Merge branch 'develop' into hybrid-tablefactor-3

cmake/FindTBB.cmake

@@ -1,323 +0,0 @@
-# The MIT License (MIT)
-#
-# Copyright (c) 2015 Justus Calvin
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in all
-# copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-# SOFTWARE.
-
-#
-# FindTBB
-# -------
-#
-# Find TBB include directories and libraries.
-#
-# Usage:
-#
-#  find_package(TBB [major[.minor]] [EXACT]
-#               [QUIET] [REQUIRED]
-#               [[COMPONENTS] [components...]]
-#               [OPTIONAL_COMPONENTS components...])
-#
-# where the allowed components are tbbmalloc and tbb_preview. Users may modify
-# the behavior of this module with the following variables:
-#
-# * TBB_ROOT_DIR          - The base directory the of TBB installation.
-# * TBB_INCLUDE_DIR       - The directory that contains the TBB headers files.
-# * TBB_LIBRARY           - The directory that contains the TBB library files.
-# * TBB_<library>_LIBRARY - The path of the TBB the corresponding TBB library.
-#                           These libraries, if specified, override the
-#                           corresponding library search results, where <library>
-#                           may be tbb, tbb_debug, tbbmalloc, tbbmalloc_debug,
-#                           tbb_preview, or tbb_preview_debug.
-# * TBB_USE_DEBUG_BUILD   - The debug version of tbb libraries, if present, will
-#                           be used instead of the release version.
-#
-# Users may modify the behavior of this module with the following environment
-# variables:
-#
-# * TBB_INSTALL_DIR
-# * TBBROOT
-# * LIBRARY_PATH
-#
-# This module will set the following variables:
-#
-# * TBB_FOUND             - Set to false, or undefined, if we haven’t found, or
-#                           don’t want to use TBB.
-# * TBB_<component>_FOUND - If False, optional <component> part of TBB sytem is
-#                           not available.
-# * TBB_VERSION           - The full version string
-# * TBB_VERSION_MAJOR     - The major version
-# * TBB_VERSION_MINOR     - The minor version
-# * TBB_INTERFACE_VERSION - The interface version number defined in
-#                           tbb/tbb_stddef.h.
-# * TBB_<library>_LIBRARY_RELEASE - The path of the TBB release version of
-#                           <library>, where <library> may be tbb, tbb_debug,
-#                           tbbmalloc, tbbmalloc_debug, tbb_preview, or
-#                           tbb_preview_debug.
-# * TBB_<library>_LIBRARY_DEGUG - The path of the TBB release version of
-#                           <library>, where <library> may be tbb, tbb_debug,
-#                           tbbmalloc, tbbmalloc_debug, tbb_preview, or
-#                           tbb_preview_debug.
-#
-# The following varibles should be used to build and link with TBB:
-#
-# * TBB_INCLUDE_DIRS        - The include directory for TBB.
-# * TBB_LIBRARIES           - The libraries to link against to use TBB.
-# * TBB_LIBRARIES_RELEASE   - The release libraries to link against to use TBB.
-# * TBB_LIBRARIES_DEBUG     - The debug libraries to link against to use TBB.
-# * TBB_DEFINITIONS         - Definitions to use when compiling code that uses
-#                             TBB.
-# * TBB_DEFINITIONS_RELEASE - Definitions to use when compiling release code that
-#                             uses TBB.
-# * TBB_DEFINITIONS_DEBUG   - Definitions to use when compiling debug code that
-#                             uses TBB.
-#
-# This module will also create the "tbb" target that may be used when building
-# executables and libraries.
-
-include(FindPackageHandleStandardArgs)
-
-if(NOT TBB_FOUND)
-
-  ##################################
-  # Check the build type
-  ##################################
-
-  if(NOT DEFINED TBB_USE_DEBUG_BUILD)
-    # Set build type to RELEASE by default for optimization.
-    set(TBB_BUILD_TYPE RELEASE)
-  elseif(TBB_USE_DEBUG_BUILD)
-    set(TBB_BUILD_TYPE DEBUG)
-  else()
-    set(TBB_BUILD_TYPE RELEASE)
-  endif()
-
-  ##################################
-  # Set the TBB search directories
-  ##################################
-
-  # Define search paths based on user input and environment variables
-  set(TBB_SEARCH_DIR ${TBB_ROOT_DIR} $ENV{TBB_INSTALL_DIR} $ENV{TBBROOT})
-
-  # Define the search directories based on the current platform
-  if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
-    set(TBB_DEFAULT_SEARCH_DIR "C:/Program Files/Intel/TBB"
-                               "C:/Program Files (x86)/Intel/TBB")
-
-    # Set the target architecture
-    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
-      set(TBB_ARCHITECTURE "intel64")
-    else()
-      set(TBB_ARCHITECTURE "ia32")
-    endif()
-
-    # Set the TBB search library path search suffix based on the version of VC
-    if(WINDOWS_STORE)
-      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc11_ui")
-    elseif(MSVC14)
-      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc14")
-    elseif(MSVC12)
-      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc12")
-    elseif(MSVC11)
-      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc11")
-    elseif(MSVC10)
-      set(TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc10")
-    endif()
-
-    # Add the library path search suffix for the VC independent version of TBB
-    list(APPEND TBB_LIB_PATH_SUFFIX "lib/${TBB_ARCHITECTURE}/vc_mt")
-
-  elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
-    # OS X
-    set(TBB_DEFAULT_SEARCH_DIR "/opt/intel/tbb"
-                               "/usr/local/opt/tbb")
-
-    # TODO: Check to see which C++ library is being used by the compiler.
-    if(NOT ${CMAKE_SYSTEM_VERSION} VERSION_LESS 13.0)
-      # The default C++ library on OS X 10.9 and later is libc++
-      set(TBB_LIB_PATH_SUFFIX "lib/libc++" "lib")
-    else()
-      set(TBB_LIB_PATH_SUFFIX "lib")
-    endif()
-  elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-    # Linux
-    set(TBB_DEFAULT_SEARCH_DIR "/opt/intel/tbb")
-
-    # TODO: Check compiler version to see the suffix should be <arch>/gcc4.1 or
-    #       <arch>/gcc4.1. For now, assume that the compiler is more recent than
-    #       gcc 4.4.x or later.
-    if(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
-      set(TBB_LIB_PATH_SUFFIX "lib/intel64/gcc4.4")
-    elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
-      set(TBB_LIB_PATH_SUFFIX "lib/ia32/gcc4.4")
-    endif()
-  endif()
-
-  ##################################
-  # Find the TBB include dir
-  ##################################
-
-  find_path(TBB_INCLUDE_DIRS tbb/tbb.h
-      HINTS ${TBB_INCLUDE_DIR} ${TBB_SEARCH_DIR}
-      PATHS ${TBB_DEFAULT_SEARCH_DIR}
-      PATH_SUFFIXES include)
-
-  ##################################
-  # Set version strings
-  ##################################
-
-  if(TBB_INCLUDE_DIRS)
-    set(_tbb_version_file_prior_to_tbb_2021_1 "${TBB_INCLUDE_DIRS}/tbb/tbb_stddef.h")
-    set(_tbb_version_file_after_tbb_2021_1 "${TBB_INCLUDE_DIRS}/oneapi/tbb/version.h")
-
-    if (EXISTS "${_tbb_version_file_prior_to_tbb_2021_1}")
-      file(READ "${_tbb_version_file_prior_to_tbb_2021_1}" _tbb_version_file )
-    elseif (EXISTS "${_tbb_version_file_after_tbb_2021_1}")
-      file(READ "${_tbb_version_file_after_tbb_2021_1}" _tbb_version_file )
-    else()
-        message(FATAL_ERROR "Found TBB installation: ${TBB_INCLUDE_DIRS} "
-      "missing version header.")
-    endif()
-
-    string(REGEX REPLACE ".*#define TBB_VERSION_MAJOR ([0-9]+).*" "\\1"
-        TBB_VERSION_MAJOR "${_tbb_version_file}")
-    string(REGEX REPLACE ".*#define TBB_VERSION_MINOR ([0-9]+).*" "\\1"
-        TBB_VERSION_MINOR "${_tbb_version_file}")
-    string(REGEX REPLACE ".*#define TBB_INTERFACE_VERSION ([0-9]+).*" "\\1"
-        TBB_INTERFACE_VERSION "${_tbb_version_file}")
-    set(TBB_VERSION "${TBB_VERSION_MAJOR}.${TBB_VERSION_MINOR}")
-  endif()
-
-  ##################################
-  # Find TBB components
-  ##################################
-
-  if(TBB_VERSION VERSION_LESS 4.3)
-    set(TBB_SEARCH_COMPOMPONENTS tbb_preview tbbmalloc tbb)
-  else()
-    set(TBB_SEARCH_COMPOMPONENTS tbb_preview tbbmalloc_proxy tbbmalloc tbb)
-  endif()
-
-  # Find each component
-  foreach(_comp ${TBB_SEARCH_COMPOMPONENTS})
-    if(";${TBB_FIND_COMPONENTS};tbb;" MATCHES ";${_comp};")
-
-      # Search for the libraries
-      find_library(TBB_${_comp}_LIBRARY_RELEASE ${_comp}
-          HINTS ${TBB_LIBRARY} ${TBB_SEARCH_DIR}
-          PATHS ${TBB_DEFAULT_SEARCH_DIR} ENV LIBRARY_PATH
-          PATH_SUFFIXES ${TBB_LIB_PATH_SUFFIX})
-
-      find_library(TBB_${_comp}_LIBRARY_DEBUG ${_comp}_debug
-          HINTS ${TBB_LIBRARY} ${TBB_SEARCH_DIR}
-          PATHS ${TBB_DEFAULT_SEARCH_DIR} ENV LIBRARY_PATH
-          PATH_SUFFIXES ${TBB_LIB_PATH_SUFFIX})
-
-      if(TBB_${_comp}_LIBRARY_DEBUG)
-        list(APPEND TBB_LIBRARIES_DEBUG "${TBB_${_comp}_LIBRARY_DEBUG}")
-      endif()
-      if(TBB_${_comp}_LIBRARY_RELEASE)
-        list(APPEND TBB_LIBRARIES_RELEASE "${TBB_${_comp}_LIBRARY_RELEASE}")
-      endif()
-      if(TBB_${_comp}_LIBRARY_${TBB_BUILD_TYPE} AND NOT TBB_${_comp}_LIBRARY)
-        set(TBB_${_comp}_LIBRARY "${TBB_${_comp}_LIBRARY_${TBB_BUILD_TYPE}}")
-      endif()
-
-      if(TBB_${_comp}_LIBRARY AND EXISTS "${TBB_${_comp}_LIBRARY}")
-        set(TBB_${_comp}_FOUND TRUE)
-      else()
-        set(TBB_${_comp}_FOUND FALSE)
-      endif()
-
-      # Mark internal variables as advanced
-      mark_as_advanced(TBB_${_comp}_LIBRARY_RELEASE)
-      mark_as_advanced(TBB_${_comp}_LIBRARY_DEBUG)
-      mark_as_advanced(TBB_${_comp}_LIBRARY)
-
-    endif()
-  endforeach()
-
-  ##################################
-  # Set compile flags and libraries
-  ##################################
-
-  set(TBB_DEFINITIONS_RELEASE "")
-  set(TBB_DEFINITIONS_DEBUG "-DTBB_USE_DEBUG=1")
-
-  if(TBB_LIBRARIES_${TBB_BUILD_TYPE})
-    set(TBB_DEFINITIONS "${TBB_DEFINITIONS_${TBB_BUILD_TYPE}}")
-    set(TBB_LIBRARIES "${TBB_LIBRARIES_${TBB_BUILD_TYPE}}")
-  elseif(TBB_LIBRARIES_RELEASE)
-    set(TBB_DEFINITIONS "${TBB_DEFINITIONS_RELEASE}")
-    set(TBB_LIBRARIES "${TBB_LIBRARIES_RELEASE}")
-  elseif(TBB_LIBRARIES_DEBUG)
-    set(TBB_DEFINITIONS "${TBB_DEFINITIONS_DEBUG}")
-    set(TBB_LIBRARIES "${TBB_LIBRARIES_DEBUG}")
-  endif()
-
-  find_package_handle_standard_args(TBB
-      REQUIRED_VARS TBB_INCLUDE_DIRS TBB_LIBRARIES
-      HANDLE_COMPONENTS
-      VERSION_VAR TBB_VERSION)
-
-  ##################################
-  # Create targets
-  ##################################
-
-  if(NOT CMAKE_VERSION VERSION_LESS 3.0 AND TBB_FOUND)
-    # Start fix to support different targets for tbb, tbbmalloc, etc.
-    # (Jose Luis Blanco, Jan 2019)
-    # Iterate over tbb, tbbmalloc, etc.
-    foreach(libname ${TBB_SEARCH_COMPOMPONENTS})
-      if ((NOT TBB_${libname}_LIBRARY_RELEASE) AND (NOT TBB_${libname}_LIBRARY_DEBUG))
-        continue()
-      endif()
-
-      add_library(${libname} SHARED IMPORTED)
-
-      set_target_properties(${libname} PROPERTIES
-            INTERFACE_INCLUDE_DIRECTORIES  ${TBB_INCLUDE_DIRS}
-            IMPORTED_LOCATION              ${TBB_${libname}_LIBRARY_RELEASE})
-      if(TBB_${libname}_LIBRARY_RELEASE AND TBB_${libname}_LIBRARY_DEBUG)
-        set_target_properties(${libname} PROPERTIES
-            INTERFACE_COMPILE_DEFINITIONS "$<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:TBB_USE_DEBUG=1>"
-            IMPORTED_LOCATION_DEBUG          ${TBB_${libname}_LIBRARY_DEBUG}
-            IMPORTED_LOCATION_RELWITHDEBINFO ${TBB_${libname}_LIBRARY_DEBUG}
-            IMPORTED_LOCATION_RELEASE        ${TBB_${libname}_LIBRARY_RELEASE}
-            IMPORTED_LOCATION_MINSIZEREL     ${TBB_${libname}_LIBRARY_RELEASE}
-            )
-      elseif(TBB_${libname}_LIBRARY_RELEASE)
-        set_target_properties(${libname} PROPERTIES IMPORTED_LOCATION ${TBB_${libname}_LIBRARY_RELEASE})
-      else()
-        set_target_properties(${libname} PROPERTIES
-            INTERFACE_COMPILE_DEFINITIONS "${TBB_DEFINITIONS_DEBUG}"
-            IMPORTED_LOCATION              ${TBB_${libname}_LIBRARY_DEBUG}
-            )
-      endif()
-    endforeach()
-    # End of fix to support different targets
-  endif()
-
-  mark_as_advanced(TBB_INCLUDE_DIRS TBB_LIBRARIES)
-
-  unset(TBB_ARCHITECTURE)
-  unset(TBB_BUILD_TYPE)
-  unset(TBB_LIB_PATH_SUFFIX)
-  unset(TBB_DEFAULT_SEARCH_DIR)
-
-endif()

cmake/HandleTBB.cmake

@@ -14,7 +14,7 @@ if (GTSAM_WITH_TBB)
         endif()
         # all definitions and link requisites will go via imported targets:
         # tbb & tbbmalloc
-        list(APPEND GTSAM_ADDITIONAL_LIBRARIES tbb tbbmalloc)
+        list(APPEND GTSAM_ADDITIONAL_LIBRARIES TBB::tbb TBB::tbbmalloc)
     else()
         set(GTSAM_USE_TBB 0)  # This will go into config.h
     endif()

gtsam/base/Group.h

@@ -22,13 +22,6 @@
 
 #include <gtsam/base/Testable.h>
 
-#ifdef GTSAM_USE_BOOST_FEATURES
-#include <boost/concept_check.hpp>
-#include <boost/concept/requires.hpp>
-#include <boost/type_traits/is_base_of.hpp>
-#include <boost/static_assert.hpp>
-#endif
-
 #include <utility>
 
 namespace gtsam {

gtsam/base/timing.cpp

@@ -19,9 +19,10 @@
 #include <gtsam/base/debug.h>
 #include <gtsam/base/timing.h>
 
+#include <algorithm>
+#include <cassert>
 #include <cmath>
 #include <cstddef>
-#include <cassert>
 #include <iomanip>
 #include <iostream>
 #include <map>

gtsam/base/types.h

@@ -19,16 +19,11 @@
 
 #pragma once
 
+#include <gtsam/config.h>  // for GTSAM_USE_TBB
 #include <gtsam/dllexport.h>
-#ifdef GTSAM_USE_BOOST_FEATURES
-#include <boost/concept/assert.hpp>
-#include <boost/range/concepts.hpp>
-#endif
-#include <gtsam/config.h> // for GTSAM_USE_TBB
 
 #include <cstddef>
 #include <cstdint>
-
 #include <exception>
 #include <string>
 

gtsam/discrete/AlgebraicDecisionTree.h

@@ -29,9 +29,9 @@
 namespace gtsam {
 
   /**
-   * Algebraic Decision Trees fix the range to double
+   * An algebraic decision tree fixes the range of a DecisionTree to double.
-   * Just has some nice constructors and some syntactic sugar
+   * Just has some nice constructors and some syntactic sugar.
-   * TODO: consider eliminating this class altogether?
+   * TODO(dellaert): consider eliminating this class altogether?
    *
    * @ingroup discrete
    */
@@ -81,20 +81,62 @@ namespace gtsam {
     AlgebraicDecisionTree(const L& label, double y1, double y2)
         : Base(label, y1, y2) {}
 
-    /** Create a new leaf function splitting on a variable */
+    /**
+     * @brief Create a new leaf function splitting on a variable
+     *
+     * @param labelC: The label with cardinality 2
+     * @param y1: The value for the first key
+     * @param y2: The value for the second key
+     *
+     * Example:
+     * @code{.cpp}
+     * std::pair<string, size_t> A {"a", 2};
+     * AlgebraicDecisionTree<string> a(A, 0.6, 0.4);
+     * @endcode
+     */
     AlgebraicDecisionTree(const typename Base::LabelC& labelC, double y1,
                           double y2)
         : Base(labelC, y1, y2) {}
 
-    /** Create from keys and vector table */
+    /** 
+     * @brief Create from keys with cardinalities and a vector table
+     * 
+     * @param labelCs: The keys, with cardinalities, given as pairs
+     * @param ys: The vector table
+     *
+     * Example with three keys, A, B, and C, with cardinalities 2, 3, and 2,
+     * respectively, and a vector table of size 12:
+     * @code{.cpp}
+     * DiscreteKey A(0, 2), B(1, 3), C(2, 2);
+     * const vector<double> cpt{
+     *   1.0 / 3, 2.0 / 3, 3.0 / 7, 4.0 / 7, 5.0 / 11, 6.0 / 11,  //
+     *   1.0 / 9, 8.0 / 9, 3.0 / 6, 3.0 / 6, 5.0 / 10, 5.0 / 10};
+     * AlgebraicDecisionTree<Key> expected(A & B & C, cpt);
+     * @endcode
+     * The table is given in the following order:
+     *   A=0, B=0, C=0
+     *   A=0, B=0, C=1
+     *   ...
+     *   A=1, B=1, C=1
+     * Hence, the first line in the table is for A==0, and the second for A==1.
+     * In each line, the first two entries are for B==0, the next two for B==1,
+     * and the last two for B==2. Each pair is for a C value of 0 and 1.
+     */
     AlgebraicDecisionTree  //
         (const std::vector<typename Base::LabelC>& labelCs,
-        const std::vector<double>& ys) {
+         const std::vector<double>& ys) {
       this->root_ =
           Base::create(labelCs.begin(), labelCs.end(), ys.begin(), ys.end());
     }
 
-    /** Create from keys and string table */
+    /** 
+     * @brief Create from keys and string table
+     * 
+     * @param labelCs: The keys, with cardinalities, given as pairs
+     * @param table: The string table, given as a string of doubles.
+     * 
+     * @note Table needs to be in same order as the vector table in the other constructor.
+     */
     AlgebraicDecisionTree  //
         (const std::vector<typename Base::LabelC>& labelCs,
         const std::string& table) {
@@ -109,7 +151,13 @@ namespace gtsam {
           Base::create(labelCs.begin(), labelCs.end(), ys.begin(), ys.end());
     }
 
-    /** Create a new function splitting on a variable */
+    /** 
+     * @brief Create a range of decision trees, splitting on a single variable.
+     * 
+     * @param begin: Iterator to beginning of a range of decision trees
+     * @param end: Iterator to end of a range of decision trees
+     * @param label: The label to split on
+     */
     template <typename Iterator>
     AlgebraicDecisionTree(Iterator begin, Iterator end, const L& label)
         : Base(nullptr) {

gtsam/discrete/DecisionTree-inl.h

@@ -93,7 +93,8 @@ namespace gtsam {
     /// print
     void print(const std::string& s, const LabelFormatter& labelFormatter,
                const ValueFormatter& valueFormatter) const override {
-      std::cout << s << " Leaf " << valueFormatter(constant_) << std::endl;
+      std::cout << s << " Leaf [" << nrAssignments() << "] "
+                << valueFormatter(constant_) << std::endl;
     }
 
     /** Write graphviz format to stream `os`. */
@@ -626,7 +627,7 @@ namespace gtsam {
   // B=1
   //  A=0: 3
   //  A=1: 4
-  // Note, through the magic of "compose", create([A B],[1 2 3 4]) will produce
+  // Note, through the magic of "compose", create([A B],[1 3 2 4]) will produce
   // exactly the same tree as above: the highest label is always the root.
   // However, it will be *way* faster if labels are given highest to lowest.
   template<typename L, typename Y>
@@ -827,6 +828,16 @@ namespace gtsam {
     return total;
   }
 
+  /****************************************************************************/
+  template <typename L, typename Y>
+  size_t DecisionTree<L, Y>::nrAssignments() const {
+    size_t n = 0;
+    this->visitLeaf([&n](const DecisionTree<L, Y>::Leaf& leaf) {
+      n += leaf.nrAssignments();
+    });
+    return n;
+  }
+
   /****************************************************************************/
   // fold is just done with a visit
   template <typename L, typename Y>

gtsam/discrete/DecisionTree.h

@@ -39,9 +39,23 @@
 namespace gtsam {
 
   /**
-   * Decision Tree
+   * @brief a decision tree is a function from assignments to values.
-   * L = label for variables
+   * @tparam L label for variables
-   * Y = function range (any algebra), e.g., bool, int, double
+   * @tparam Y function range (any algebra), e.g., bool, int, double
+   * 
+   * After creating a decision tree on some variables, the tree can be evaluated
+   * on an assignment to those variables. Example:
+   * 
+   * @code{.cpp}
+   * // Create a decision stump one one variable 'a' with values 10 and 20.
+   * DecisionTree<char, int> tree('a', 10, 20);
+   * 
+   * // Evaluate the tree on an assignment to the variable.
+   * int value0 = tree({{'a', 0}}); // value0 = 10
+   * int value1 = tree({{'a', 1}}); // value1 = 20
+   * @endcode
+   * 
+   * More examples can be found in testDecisionTree.cpp
    *
    * @ingroup discrete
    */
@@ -136,7 +150,8 @@ namespace gtsam {
     NodePtr root_;
 
    protected:
-    /** Internal recursive function to create from keys, cardinalities, 
+    /** 
+     * Internal recursive function to create from keys, cardinalities, 
      * and Y values 
      */
     template<typename It, typename ValueIt>
@@ -167,7 +182,13 @@ namespace gtsam {
     /** Create a constant */
     explicit DecisionTree(const Y& y);
 
-    /// Create tree with 2 assignments `y1`, `y2`, splitting on variable `label`
+    /**
+     * @brief Create tree with 2 assignments `y1`, `y2`, splitting on variable `label`
+     * 
+     * @param label The variable to split on.
+     * @param y1 The value for the first assignment.
+     * @param y2 The value for the second assignment.
+     */
     DecisionTree(const L& label, const Y& y1, const Y& y2);
 
     /** Allow Label+Cardinality for convenience */
@@ -299,6 +320,42 @@ namespace gtsam {
     /// Return the number of leaves in the tree.
     size_t nrLeaves() const;
 
+    /**
+     * @brief This is a convenience function which returns the total number of
+     * leaf assignments in the decision tree.
+     * This function is not used for anymajor operations within the discrete
+     * factor graph framework.
+     *
+     * Leaf assignments represent the cardinality of each leaf node, e.g. in a
+     * binary tree each leaf has 2 assignments. This includes counts removed
+     * from implicit pruning hence, it will always be >= nrLeaves().
+     *
+     * E.g. we have a decision tree as below, where each node has 2 branches:
+     *
+     * Choice(m1)
+     * 0 Choice(m0)
+     * 0 0 Leaf 0.0
+     * 0 1 Leaf 0.0
+     * 1 Choice(m0)
+     * 1 0 Leaf 1.0
+     * 1 1 Leaf 2.0
+     *
+     * In the unpruned form, the tree will have 4 assignments, 2 for each key,
+     * and 4 leaves.
+     *
+     * In the pruned form, the number of assignments is still 4 but the number
+     * of leaves is now 3, as below:
+     *
+     * Choice(m1)
+     * 0 Leaf 0.0
+     * 1 Choice(m0)
+     * 1 0 Leaf 1.0
+     * 1 1 Leaf 2.0
+     *
+     * @return size_t
+     */
+    size_t nrAssignments() const;
+
     /**
      * @brief Fold a binary function over the tree, returning accumulator.
      *

gtsam/discrete/DecisionTreeFactor.cpp

@@ -117,6 +117,14 @@ namespace gtsam {
     return DecisionTreeFactor(keys, result);
   }
 
+  /* ************************************************************************ */
+  DecisionTreeFactor DecisionTreeFactor::apply(ADT::UnaryAssignment op) const {
+    // apply operand
+    ADT result = ADT::apply(op);
+    // Make a new factor
+    return DecisionTreeFactor(discreteKeys(), result);
+  }
+
   /* ************************************************************************ */
   DecisionTreeFactor::shared_ptr DecisionTreeFactor::combine(
       size_t nrFrontals, ADT::Binary op) const {

gtsam/discrete/DecisionTreeFactor.h

@@ -59,11 +59,46 @@ namespace gtsam {
     /** Constructor from DiscreteKeys and AlgebraicDecisionTree */
     DecisionTreeFactor(const DiscreteKeys& keys, const ADT& potentials);
 
-    /** Constructor from doubles */
+    /**
+     * @brief Constructor from doubles
+     *
+     * @param keys The discrete keys.
+     * @param table The table of values.
+     *
+     * @throw std::invalid_argument if the size of `table` does not match the
+     * number of assignments.
+     *
+     * Example:
+     * @code{.cpp}
+     * DiscreteKey X(0,2), Y(1,3);
+     * const std::vector<double> table {2, 5, 3, 6, 4, 7};
+     * DecisionTreeFactor f1({X, Y}, table);
+     * @endcode
+     *
+     * The values in the table should be laid out so that the first key varies
+     * the slowest, and the last key the fastest.
+     */
     DecisionTreeFactor(const DiscreteKeys& keys,
-                      const std::vector<double>& table);
+                       const std::vector<double>& table);
 
-    /** Constructor from string */
+    /**
+     * @brief Constructor from string
+     *
+     * @param keys The discrete keys.
+     * @param table The table of values.
+     *
+     * @throw std::invalid_argument if the size of `table` does not match the
+     * number of assignments.
+     *
+     * Example:
+     * @code{.cpp}
+     * DiscreteKey X(0,2), Y(1,3);
+     * DecisionTreeFactor factor({X, Y}, "2 5 3 6 4 7");
+     * @endcode
+     *
+     * The values in the table should be laid out so that the first key varies
+     * the slowest, and the last key the fastest.
+     */
     DecisionTreeFactor(const DiscreteKeys& keys, const std::string& table);
 
     /// Single-key specialization

gtsam/discrete/DiscreteBayesTree.h

@@ -58,6 +58,11 @@ class GTSAM_EXPORT DiscreteBayesTreeClique
 
   //** evaluate conditional probability of subtree for given DiscreteValues */
   double evaluate(const DiscreteValues& values) const;
+
+  //** (Preferred) sugar for the above for given DiscreteValues */
+  double operator()(const DiscreteValues& values) const {
+    return evaluate(values);
+  }
 };
 
 /* ************************************************************************* */

gtsam/discrete/DiscreteFactorGraph.h

@@ -41,16 +41,30 @@ class DiscreteJunctionTree;
 
 /**
  * @brief Main elimination function for DiscreteFactorGraph.
- * 
+ *
- * @param factors 
+ * @param factors The factor graph to eliminate.
- * @param keys 
+ * @param frontalKeys An ordering for which variables to eliminate.
- * @return GTSAM_EXPORT
+ * @return A pair of the resulting conditional and the separator factor.
  * @ingroup discrete
  */
-GTSAM_EXPORT std::pair<std::shared_ptr<DiscreteConditional>, DecisionTreeFactor::shared_ptr>
+GTSAM_EXPORT
-EliminateDiscrete(const DiscreteFactorGraph& factors, const Ordering& keys);
+std::pair<DiscreteConditional::shared_ptr, DecisionTreeFactor::shared_ptr>
+EliminateDiscrete(const DiscreteFactorGraph& factors,
+                  const Ordering& frontalKeys);
+
+/**
+ * @brief Alternate elimination function for that creates non-normalized lookup tables.
+ *
+ * @param factors The factor graph to eliminate.
+ * @param frontalKeys An ordering for which variables to eliminate.
+ * @return A pair of the resulting lookup table and the separator factor.
+ * @ingroup discrete
+ */
+GTSAM_EXPORT
+std::pair<DiscreteConditional::shared_ptr, DecisionTreeFactor::shared_ptr>
+EliminateForMPE(const DiscreteFactorGraph& factors,
+                const Ordering& frontalKeys);
 
-/* ************************************************************************* */
 template<> struct EliminationTraits<DiscreteFactorGraph>
 {
   typedef DiscreteFactor FactorType;                   ///< Type of factors in factor graph
@@ -60,12 +74,14 @@ template<> struct EliminationTraits<DiscreteFactorGraph>
   typedef DiscreteEliminationTree EliminationTreeType; ///< Type of elimination tree
   typedef DiscreteBayesTree BayesTreeType;             ///< Type of Bayes tree
   typedef DiscreteJunctionTree JunctionTreeType;       ///< Type of Junction tree
+  
   /// The default dense elimination function
   static std::pair<std::shared_ptr<ConditionalType>,
                    std::shared_ptr<FactorType> >
   DefaultEliminate(const FactorGraphType& factors, const Ordering& keys) {
     return EliminateDiscrete(factors, keys);
   }
+  
   /// The default ordering generation function
   static Ordering DefaultOrderingFunc(
       const FactorGraphType& graph,
@@ -74,7 +90,6 @@ template<> struct EliminationTraits<DiscreteFactorGraph>
   }
 };
 
-/* ************************************************************************* */
 /**
  * A Discrete Factor Graph is a factor graph where all factors are Discrete, i.e.
  *   Factor == DiscreteFactor
@@ -108,8 +123,8 @@ class GTSAM_EXPORT DiscreteFactorGraph
 
   /** Implicit copy/downcast constructor to override explicit template container
    * constructor */
-  template <class DERIVEDFACTOR>
+  template <class DERIVED_FACTOR>
-  DiscreteFactorGraph(const FactorGraph<DERIVEDFACTOR>& graph) : Base(graph) {}
+  DiscreteFactorGraph(const FactorGraph<DERIVED_FACTOR>& graph) : Base(graph) {}
 
   /// @name Testable
   /// @{
@@ -227,10 +242,6 @@ class GTSAM_EXPORT DiscreteFactorGraph
   /// @}
 };  // \ DiscreteFactorGraph
 
-std::pair<DiscreteConditional::shared_ptr, DecisionTreeFactor::shared_ptr>  //
-EliminateForMPE(const DiscreteFactorGraph& factors,
-                const Ordering& frontalKeys);
-
 /// traits
 template <>
 struct traits<DiscreteFactorGraph> : public Testable<DiscreteFactorGraph> {};

gtsam/discrete/DiscreteJunctionTree.h

@@ -66,4 +66,6 @@ namespace gtsam {
     DiscreteJunctionTree(const DiscreteEliminationTree& eliminationTree);
   };
 
+  /// typedef for wrapper:
+  using DiscreteCluster = DiscreteJunctionTree::Cluster;
 }

gtsam/discrete/DiscreteValues.h

@@ -120,6 +120,11 @@ class GTSAM_EXPORT DiscreteValues : public Assignment<Key> {
   /// @}
 };
 
+/// Free version of CartesianProduct.
+inline std::vector<DiscreteValues> cartesianProduct(const DiscreteKeys& keys) {
+  return DiscreteValues::CartesianProduct(keys);
+}
+
 /// Free version of markdown.
 std::string markdown(const DiscreteValues& values,
                      const KeyFormatter& keyFormatter = DefaultKeyFormatter,

gtsam/discrete/discrete.i

@@ -17,6 +17,8 @@ class DiscreteKeys {
 };
 
 // DiscreteValues is added in specializations/discrete.h as a std::map
+std::vector<gtsam::DiscreteValues> cartesianProduct(
+    const gtsam::DiscreteKeys& keys);
 string markdown(
     const gtsam::DiscreteValues& values,
     const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter);
@@ -31,27 +33,30 @@ string html(const gtsam::DiscreteValues& values,
             std::map<gtsam::Key, std::vector<std::string>> names);
 
 #include <gtsam/discrete/DiscreteFactor.h>
-class DiscreteFactor {
+virtual class DiscreteFactor : gtsam::Factor {
   void print(string s = "DiscreteFactor\n",
              const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::DiscreteFactor& other, double tol = 1e-9) const;
-  bool empty() const;
-  size_t size() const;
   double operator()(const gtsam::DiscreteValues& values) const;
 };
 
 #include <gtsam/discrete/DecisionTreeFactor.h>
 virtual class DecisionTreeFactor : gtsam::DiscreteFactor {
   DecisionTreeFactor();
-  
+
   DecisionTreeFactor(const gtsam::DiscreteKey& key,
                      const std::vector<double>& spec);
   DecisionTreeFactor(const gtsam::DiscreteKey& key, string table);
-  
+
+  DecisionTreeFactor(const gtsam::DiscreteKeys& keys,
+                     const std::vector<double>& table);
   DecisionTreeFactor(const gtsam::DiscreteKeys& keys, string table);
+
+  DecisionTreeFactor(const std::vector<gtsam::DiscreteKey>& keys,
+                     const std::vector<double>& table);
   DecisionTreeFactor(const std::vector<gtsam::DiscreteKey>& keys, string table);
-  
+
   DecisionTreeFactor(const gtsam::DiscreteConditional& c);
   
   void print(string s = "DecisionTreeFactor\n",
@@ -59,6 +64,8 @@ virtual class DecisionTreeFactor : gtsam::DiscreteFactor {
                  gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::DecisionTreeFactor& other, double tol = 1e-9) const;
 
+  size_t cardinality(gtsam::Key j) const;
+  
   double operator()(const gtsam::DiscreteValues& values) const;
   gtsam::DecisionTreeFactor operator*(const gtsam::DecisionTreeFactor& f) const;
   size_t cardinality(gtsam::Key j) const;
@@ -66,6 +73,7 @@ virtual class DecisionTreeFactor : gtsam::DiscreteFactor {
   gtsam::DecisionTreeFactor* sum(size_t nrFrontals) const;
   gtsam::DecisionTreeFactor* sum(const gtsam::Ordering& keys) const;
   gtsam::DecisionTreeFactor* max(size_t nrFrontals) const;
+  gtsam::DecisionTreeFactor* max(const gtsam::Ordering& keys) const;
 
   string dot(
       const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter,
@@ -203,10 +211,16 @@ class DiscreteBayesTreeClique {
   DiscreteBayesTreeClique(const gtsam::DiscreteConditional* conditional);
   const gtsam::DiscreteConditional* conditional() const;
   bool isRoot() const;
+  size_t nrChildren() const;
+  const gtsam::DiscreteBayesTreeClique* operator[](size_t i) const;
+  void print(string s = "DiscreteBayesTreeClique",
+             const gtsam::KeyFormatter& keyFormatter =
+                 gtsam::DefaultKeyFormatter) const;
   void printSignature(
       const string& s = "Clique: ",
       const gtsam::KeyFormatter& formatter = gtsam::DefaultKeyFormatter) const;
   double evaluate(const gtsam::DiscreteValues& values) const;
+  double operator()(const gtsam::DiscreteValues& values) const;
 };
 
 class DiscreteBayesTree {
@@ -220,6 +234,9 @@ class DiscreteBayesTree {
   bool empty() const;
   const DiscreteBayesTreeClique* operator[](size_t j) const;
 
+  double evaluate(const gtsam::DiscreteValues& values) const;
+  double operator()(const gtsam::DiscreteValues& values) const;
+
   string dot(const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
   void saveGraph(string s,
@@ -242,9 +259,9 @@ class DiscreteBayesTree {
 class DiscreteLookupTable : gtsam::DiscreteConditional{
   DiscreteLookupTable(size_t nFrontals, const gtsam::DiscreteKeys& keys,
                       const gtsam::DecisionTreeFactor::ADT& potentials);
-  void print(
+  void print(string s = "Discrete Lookup Table: ",
-    const std::string& s = "Discrete Lookup Table: ",
+             const gtsam::KeyFormatter& keyFormatter =
-    const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter) const;
+                 gtsam::DefaultKeyFormatter) const;
   size_t argmax(const gtsam::DiscreteValues& parentsValues) const;
 };
 
@@ -263,6 +280,14 @@ class DiscreteLookupDAG {
 };
 
 #include <gtsam/discrete/DiscreteFactorGraph.h>
+std::pair<gtsam::DiscreteConditional*, gtsam::DecisionTreeFactor*>
+EliminateDiscrete(const gtsam::DiscreteFactorGraph& factors,
+                  const gtsam::Ordering& frontalKeys);
+
+std::pair<gtsam::DiscreteConditional*, gtsam::DecisionTreeFactor*>
+EliminateForMPE(const gtsam::DiscreteFactorGraph& factors,
+                const gtsam::Ordering& frontalKeys);
+
 class DiscreteFactorGraph {
   DiscreteFactorGraph();
   DiscreteFactorGraph(const gtsam::DiscreteBayesNet& bayesNet);
@@ -277,6 +302,7 @@ class DiscreteFactorGraph {
   void add(const gtsam::DiscreteKey& j, const std::vector<double>& spec);
   void add(const gtsam::DiscreteKeys& keys, string spec);
   void add(const std::vector<gtsam::DiscreteKey>& keys, string spec);
+  void add(const std::vector<gtsam::DiscreteKey>& keys, const std::vector<double>& spec);
 
   bool empty() const;
   size_t size() const;
@@ -290,25 +316,46 @@ class DiscreteFactorGraph {
   double operator()(const gtsam::DiscreteValues& values) const;
   gtsam::DiscreteValues optimize() const;
 
-  gtsam::DiscreteBayesNet sumProduct();
+  gtsam::DiscreteBayesNet sumProduct(
-  gtsam::DiscreteBayesNet sumProduct(gtsam::Ordering::OrderingType type);
+      gtsam::Ordering::OrderingType type = gtsam::Ordering::COLAMD);
   gtsam::DiscreteBayesNet sumProduct(const gtsam::Ordering& ordering);
 
-  gtsam::DiscreteLookupDAG maxProduct();
+  gtsam::DiscreteLookupDAG maxProduct(
-  gtsam::DiscreteLookupDAG maxProduct(gtsam::Ordering::OrderingType type);
+      gtsam::Ordering::OrderingType type = gtsam::Ordering::COLAMD);
   gtsam::DiscreteLookupDAG maxProduct(const gtsam::Ordering& ordering);
 
-  gtsam::DiscreteBayesNet* eliminateSequential();
+  gtsam::DiscreteBayesNet* eliminateSequential(
-  gtsam::DiscreteBayesNet* eliminateSequential(gtsam::Ordering::OrderingType type);
+      gtsam::Ordering::OrderingType type = gtsam::Ordering::COLAMD);
+  gtsam::DiscreteBayesNet* eliminateSequential(
+      gtsam::Ordering::OrderingType type,
+      const gtsam::DiscreteFactorGraph::Eliminate& function);
   gtsam::DiscreteBayesNet* eliminateSequential(const gtsam::Ordering& ordering);
+  gtsam::DiscreteBayesNet* eliminateSequential(
+      const gtsam::Ordering& ordering,
+      const gtsam::DiscreteFactorGraph::Eliminate& function);
   pair<gtsam::DiscreteBayesNet*, gtsam::DiscreteFactorGraph*>
-      eliminatePartialSequential(const gtsam::Ordering& ordering);
+  eliminatePartialSequential(const gtsam::Ordering& ordering);
+  pair<gtsam::DiscreteBayesNet*, gtsam::DiscreteFactorGraph*>
+  eliminatePartialSequential(
+      const gtsam::Ordering& ordering,
+      const gtsam::DiscreteFactorGraph::Eliminate& function);
 
-  gtsam::DiscreteBayesTree* eliminateMultifrontal();
+  gtsam::DiscreteBayesTree* eliminateMultifrontal(
-  gtsam::DiscreteBayesTree* eliminateMultifrontal(gtsam::Ordering::OrderingType type);  
+      gtsam::Ordering::OrderingType type = gtsam::Ordering::COLAMD);
-  gtsam::DiscreteBayesTree* eliminateMultifrontal(const gtsam::Ordering& ordering);  
+  gtsam::DiscreteBayesTree* eliminateMultifrontal(
+      gtsam::Ordering::OrderingType type,
+      const gtsam::DiscreteFactorGraph::Eliminate& function);
+  gtsam::DiscreteBayesTree* eliminateMultifrontal(
+      const gtsam::Ordering& ordering);
+  gtsam::DiscreteBayesTree* eliminateMultifrontal(
+      const gtsam::Ordering& ordering,
+      const gtsam::DiscreteFactorGraph::Eliminate& function);
   pair<gtsam::DiscreteBayesTree*, gtsam::DiscreteFactorGraph*>
-      eliminatePartialMultifrontal(const gtsam::Ordering& ordering);
+  eliminatePartialMultifrontal(const gtsam::Ordering& ordering);
+  pair<gtsam::DiscreteBayesTree*, gtsam::DiscreteFactorGraph*>
+  eliminatePartialMultifrontal(
+      const gtsam::Ordering& ordering,
+      const gtsam::DiscreteFactorGraph::Eliminate& function);
 
   string dot(
       const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter,
@@ -328,4 +375,41 @@ class DiscreteFactorGraph {
               std::map<gtsam::Key, std::vector<std::string>> names) const;
 };
 
+#include <gtsam/discrete/DiscreteEliminationTree.h>
+
+class DiscreteEliminationTree {
+  DiscreteEliminationTree(const gtsam::DiscreteFactorGraph& factorGraph,
+                          const gtsam::VariableIndex& structure,
+                          const gtsam::Ordering& order);
+
+  DiscreteEliminationTree(const gtsam::DiscreteFactorGraph& factorGraph,
+                          const gtsam::Ordering& order);
+
+  void print(
+      string name = "EliminationTree: ",
+      const gtsam::KeyFormatter& formatter = gtsam::DefaultKeyFormatter) const;
+  bool equals(const gtsam::DiscreteEliminationTree& other,
+              double tol = 1e-9) const;
+};
+
+#include <gtsam/discrete/DiscreteJunctionTree.h>
+
+class DiscreteCluster {
+  gtsam::Ordering orderedFrontalKeys;
+  gtsam::DiscreteFactorGraph factors;
+  const gtsam::DiscreteCluster& operator[](size_t i) const;
+  size_t nrChildren() const;
+  void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
+                                gtsam::DefaultKeyFormatter) const;
+};
+
+class DiscreteJunctionTree {
+  DiscreteJunctionTree(const gtsam::DiscreteEliminationTree& eliminationTree);
+  void print(
+      string name = "JunctionTree: ",
+      const gtsam::KeyFormatter& formatter = gtsam::DefaultKeyFormatter) const;
+  size_t nrRoots() const;
+  const gtsam::DiscreteCluster& operator[](size_t i) const;
+};
+
 }  // namespace gtsam

gtsam/discrete/tests/testDecisionTree.cpp

@@ -25,6 +25,7 @@
 #include <gtsam/base/serializationTestHelpers.h>
 #include <gtsam/discrete/DecisionTree-inl.h>
 #include <gtsam/discrete/Signature.h>
+#include <gtsam/inference/Symbol.h>
 
 #include <iomanip>
 
@@ -75,6 +76,19 @@ struct traits<CrazyDecisionTree> : public Testable<CrazyDecisionTree> {};
 
 GTSAM_CONCEPT_TESTABLE_INST(CrazyDecisionTree)
 
+/* ************************************************************************** */
+// Test char labels and int range
+/* ************************************************************************** */
+
+// Create a decision stump one one variable 'a' with values 10 and 20.
+TEST(DecisionTree, Constructor) {
+  DecisionTree<char, int> tree('a', 10, 20);
+
+  // Evaluate the tree on an assignment to the variable.
+  EXPECT_LONGS_EQUAL(10, tree({{'a', 0}}));
+  EXPECT_LONGS_EQUAL(20, tree({{'a', 1}}));
+}
+
 /* ************************************************************************** */
 // Test string labels and int range
 /* ************************************************************************** */
@@ -118,18 +132,47 @@ struct Ring {
   static inline int mul(const int& a, const int& b) { return a * b; }
 };
 
+/* ************************************************************************** */
+// Check that creating decision trees respects key order.
+TEST(DecisionTree, ConstructorOrder) {
+  // Create labels
+  string A("A"), B("B");
+
+  const std::vector<int> ys1 = {1, 2, 3, 4};
+  DT tree1({{B, 2}, {A, 2}}, ys1); // faster version, as B is "higher" than A!
+
+  const std::vector<int> ys2 = {1, 3, 2, 4};
+  DT tree2({{A, 2}, {B, 2}}, ys2); // slower version !
+
+  // Both trees will be the same, tree is order from high to low labels.
+  // Choice(B)
+  //  0 Choice(A)
+  //  0 0 Leaf 1
+  //  0 1 Leaf 2
+  //  1 Choice(A)
+  //  1 0 Leaf 3
+  //  1 1 Leaf 4
+
+  EXPECT(tree2.equals(tree1));
+
+  // Check the values are as expected by calling the () operator:
+  EXPECT_LONGS_EQUAL(1, tree1({{A, 0}, {B, 0}}));
+  EXPECT_LONGS_EQUAL(3, tree1({{A, 0}, {B, 1}}));
+  EXPECT_LONGS_EQUAL(2, tree1({{A, 1}, {B, 0}}));
+  EXPECT_LONGS_EQUAL(4, tree1({{A, 1}, {B, 1}}));
+}
+
 /* ************************************************************************** */
 // test DT
-TEST(DecisionTree, example) {
+TEST(DecisionTree, Example) {
   // Create labels
   string A("A"), B("B"), C("C");
 
-  // create a value
+  // Create assignments using brace initialization:
-  Assignment<string> x00, x01, x10, x11;
+  Assignment<string> x00{{A, 0}, {B, 0}};
-  x00[A] = 0, x00[B] = 0;
+  Assignment<string> x01{{A, 0}, {B, 1}};
-  x01[A] = 0, x01[B] = 1;
+  Assignment<string> x10{{A, 1}, {B, 0}};
-  x10[A] = 1, x10[B] = 0;
+  Assignment<string> x11{{A, 1}, {B, 1}};
-  x11[A] = 1, x11[B] = 1;
 
   // empty
   DT empty;
@@ -241,8 +284,7 @@ TEST(DecisionTree, ConvertValuesOnly) {
   StringBoolTree f2(f1, bool_of_int);
 
   // Check a value
-  Assignment<string> x00;
+  Assignment<string> x00 {{A, 0}, {B, 0}};
-  x00["A"] = 0, x00["B"] = 0;
   EXPECT(!f2(x00));
 }
 
@@ -266,10 +308,11 @@ TEST(DecisionTree, ConvertBoth) {
 
   // Check some values
   Assignment<Label> x00, x01, x10, x11;
-  x00[X] = 0, x00[Y] = 0;
+  x00 = {{X, 0}, {Y, 0}};
-  x01[X] = 0, x01[Y] = 1;
+  x01 = {{X, 0}, {Y, 1}};
-  x10[X] = 1, x10[Y] = 0;
+  x10 = {{X, 1}, {Y, 0}};
-  x11[X] = 1, x11[Y] = 1;
+  x11 = {{X, 1}, {Y, 1}};
+
   EXPECT(!f2(x00));
   EXPECT(!f2(x01));
   EXPECT(f2(x10));

gtsam/discrete/tests/testDecisionTreeFactor.cpp

@@ -27,6 +27,18 @@
 using namespace std;
 using namespace gtsam;
 
+/* ************************************************************************* */
+TEST(DecisionTreeFactor, ConstructorsMatch) {
+  // Declare two keys
+  DiscreteKey X(0, 2), Y(1, 3);
+
+  // Create with vector and with string
+  const std::vector<double> table {2, 5, 3, 6, 4, 7};
+  DecisionTreeFactor f1({X, Y}, table);
+  DecisionTreeFactor f2({X, Y}, "2 5 3 6 4 7");
+  EXPECT(assert_equal(f1, f2));
+}
+
 /* ************************************************************************* */
 TEST( DecisionTreeFactor, constructors)
 {
@@ -41,21 +53,18 @@ TEST( DecisionTreeFactor, constructors)
   EXPECT_LONGS_EQUAL(2,f2.size());
   EXPECT_LONGS_EQUAL(3,f3.size());
 
-  DiscreteValues values;
+  DiscreteValues x121{{0, 1}, {1, 2}, {2, 1}};
-  values[0] = 1; // x
+  EXPECT_DOUBLES_EQUAL(8, f1(x121), 1e-9);
-  values[1] = 2; // y
+  EXPECT_DOUBLES_EQUAL(7, f2(x121), 1e-9);
-  values[2] = 1; // z
+  EXPECT_DOUBLES_EQUAL(75, f3(x121), 1e-9);
-  EXPECT_DOUBLES_EQUAL(8, f1(values), 1e-9);
-  EXPECT_DOUBLES_EQUAL(7, f2(values), 1e-9);
-  EXPECT_DOUBLES_EQUAL(75, f3(values), 1e-9);
 
   // Assert that error = -log(value)
-  EXPECT_DOUBLES_EQUAL(-log(f1(values)), f1.error(values), 1e-9);
+  EXPECT_DOUBLES_EQUAL(-log(f1(x121)), f1.error(x121), 1e-9);
 
   // Construct from DiscreteConditional
   DiscreteConditional conditional(X | Y = "1/1 2/3 1/4");
   DecisionTreeFactor f4(conditional);
-  EXPECT_DOUBLES_EQUAL(0.8, f4(values), 1e-9);
+  EXPECT_DOUBLES_EQUAL(0.8, f4(x121), 1e-9);
 }
 
 /* ************************************************************************* */

gtsam/discrete/tests/testDiscreteBayesTree.cpp

@@ -16,23 +16,24 @@
  */
 
 #include <gtsam/base/Vector.h>
+#include <gtsam/inference/Symbol.h>
+#include <gtsam/inference/BayesNet.h>
 #include <gtsam/discrete/DiscreteBayesNet.h>
 #include <gtsam/discrete/DiscreteBayesTree.h>
 #include <gtsam/discrete/DiscreteFactorGraph.h>
-#include <gtsam/inference/BayesNet.h>
 
 #include <CppUnitLite/TestHarness.h>
 
 #include <iostream>
 #include <vector>
 
-using namespace std;
 using namespace gtsam;
 static constexpr bool debug = false;
 
 /* ************************************************************************* */
 struct TestFixture {
-  vector<DiscreteKey> keys;
+  DiscreteKeys keys;
+  std::vector<DiscreteValues> assignments;
   DiscreteBayesNet bayesNet;
   std::shared_ptr<DiscreteBayesTree> bayesTree;
 
@@ -47,6 +48,9 @@ struct TestFixture {
       keys.push_back(key_i);
     }
 
+    // Enumerate all assignments.
+    assignments = DiscreteValues::CartesianProduct(keys);
+
     // Create thin-tree Bayesnet.
     bayesNet.add(keys[14] % "1/3");
 
@@ -74,9 +78,9 @@ struct TestFixture {
 };
 
 /* ************************************************************************* */
+// Check that BN and BT give the same answer on all configurations
 TEST(DiscreteBayesTree, ThinTree) {
-  const TestFixture self;
+  TestFixture self;
-  const auto& keys = self.keys;
 
   if (debug) {
     GTSAM_PRINT(self.bayesNet);
@@ -95,47 +99,56 @@ TEST(DiscreteBayesTree, ThinTree) {
     EXPECT_LONGS_EQUAL(i, *(clique_i->conditional_->beginFrontals()));
   }
 
-  auto R = self.bayesTree->roots().front();
+  for (const auto& x : self.assignments) {
-
-  // Check whether BN and BT give the same answer on all configurations
-  auto allPosbValues = DiscreteValues::CartesianProduct(
-      keys[0] & keys[1] & keys[2] & keys[3] & keys[4] & keys[5] & keys[6] &
-      keys[7] & keys[8] & keys[9] & keys[10] & keys[11] & keys[12] & keys[13] &
-      keys[14]);
-  for (size_t i = 0; i < allPosbValues.size(); ++i) {
-    DiscreteValues x = allPosbValues[i];
     double expected = self.bayesNet.evaluate(x);
     double actual = self.bayesTree->evaluate(x);
     DOUBLES_EQUAL(expected, actual, 1e-9);
   }
+}
 
-  // Calculate all some marginals for DiscreteValues==all1
+/* ************************************************************************* */
-  Vector marginals = Vector::Zero(15);
+// Check calculation of separator marginals
-  double joint_12_14 = 0, joint_9_12_14 = 0, joint_8_12_14 = 0, joint_8_12 = 0,
+TEST(DiscreteBayesTree, SeparatorMarginals) {
-         joint82 = 0, joint12 = 0, joint24 = 0, joint45 = 0, joint46 = 0,
+  TestFixture self;
-         joint_4_11 = 0, joint_11_13 = 0, joint_11_13_14 = 0,
+
-         joint_11_12_13_14 = 0, joint_9_11_12_13 = 0, joint_8_11_12_13 = 0;
+  // Calculate some marginals for DiscreteValues==all1
-  for (size_t i = 0; i < allPosbValues.size(); ++i) {
+  double marginal_14 = 0, joint_8_12 = 0;
-    DiscreteValues x = allPosbValues[i];
+  for (auto& x : self.assignments) {
     double px = self.bayesTree->evaluate(x);
-    for (size_t i = 0; i < 15; i++)
-      if (x[i]) marginals[i] += px;
-    if (x[12] && x[14]) {
-      joint_12_14 += px;
-      if (x[9]) joint_9_12_14 += px;
-      if (x[8]) joint_8_12_14 += px;
-    }
     if (x[8] && x[12]) joint_8_12 += px;
-    if (x[2]) {
+    if (x[14]) marginal_14 += px;
-      if (x[8]) joint82 += px;
+  }
-      if (x[1]) joint12 += px;
+  DiscreteValues all1 = self.assignments.back();
-    }
+
-    if (x[4]) {
+  // check separator marginal P(S0)
-      if (x[2]) joint24 += px;
+  auto clique = (*self.bayesTree)[0];
-      if (x[5]) joint45 += px;
+  DiscreteFactorGraph separatorMarginal0 =
-      if (x[6]) joint46 += px;
+      clique->separatorMarginal(EliminateDiscrete);
-      if (x[11]) joint_4_11 += px;
+  DOUBLES_EQUAL(joint_8_12, separatorMarginal0(all1), 1e-9);
-    }
+
+  // check separator marginal P(S9), should be P(14)
+  clique = (*self.bayesTree)[9];
+  DiscreteFactorGraph separatorMarginal9 =
+      clique->separatorMarginal(EliminateDiscrete);
+  DOUBLES_EQUAL(marginal_14, separatorMarginal9(all1), 1e-9);
+
+  // check separator marginal of root, should be empty
+  clique = (*self.bayesTree)[11];
+  DiscreteFactorGraph separatorMarginal11 =
+      clique->separatorMarginal(EliminateDiscrete);
+  LONGS_EQUAL(0, separatorMarginal11.size());
+}
+
+/* ************************************************************************* */
+// Check shortcuts in the tree
+TEST(DiscreteBayesTree, Shortcuts) {
+  TestFixture self;
+
+  // Calculate some marginals for DiscreteValues==all1
+  double joint_11_13 = 0, joint_11_13_14 = 0, joint_11_12_13_14 = 0,
+         joint_9_11_12_13 = 0, joint_8_11_12_13 = 0;
+  for (auto& x : self.assignments) {
+    double px = self.bayesTree->evaluate(x);
     if (x[11] && x[13]) {
       joint_11_13 += px;
       if (x[8] && x[12]) joint_8_11_12_13 += px;
@@ -148,32 +161,12 @@ TEST(DiscreteBayesTree, ThinTree) {
       }
     }
   }
-  DiscreteValues all1 = allPosbValues.back();
+  DiscreteValues all1 = self.assignments.back();
 
-  // check separator marginal P(S0)
+  auto R = self.bayesTree->roots().front();
-  auto clique = (*self.bayesTree)[0];
-  DiscreteFactorGraph separatorMarginal0 =
-      clique->separatorMarginal(EliminateDiscrete);
-  DOUBLES_EQUAL(joint_8_12, separatorMarginal0(all1), 1e-9);
-
-  DOUBLES_EQUAL(joint_12_14, 0.1875, 1e-9);
-  DOUBLES_EQUAL(joint_8_12_14, 0.0375, 1e-9);
-  DOUBLES_EQUAL(joint_9_12_14, 0.15, 1e-9);
-
-  // check separator marginal P(S9), should be P(14)
-  clique = (*self.bayesTree)[9];
-  DiscreteFactorGraph separatorMarginal9 =
-      clique->separatorMarginal(EliminateDiscrete);
-  DOUBLES_EQUAL(marginals[14], separatorMarginal9(all1), 1e-9);
-
-  // check separator marginal of root, should be empty
-  clique = (*self.bayesTree)[11];
-  DiscreteFactorGraph separatorMarginal11 =
-      clique->separatorMarginal(EliminateDiscrete);
-  LONGS_EQUAL(0, separatorMarginal11.size());
 
   // check shortcut P(S9||R) to root
-  clique = (*self.bayesTree)[9];
+  auto clique = (*self.bayesTree)[9];
   DiscreteBayesNet shortcut = clique->shortcut(R, EliminateDiscrete);
   LONGS_EQUAL(1, shortcut.size());
   DOUBLES_EQUAL(joint_11_13_14 / joint_11_13, shortcut.evaluate(all1), 1e-9);
@@ -202,15 +195,67 @@ TEST(DiscreteBayesTree, ThinTree) {
       shortcut.print("shortcut:");
     }
   }
+}
+
+/* ************************************************************************* */
+// Check all marginals
+TEST(DiscreteBayesTree, MarginalFactors) {
+  TestFixture self;
+
+  Vector marginals = Vector::Zero(15);
+  for (size_t i = 0; i < self.assignments.size(); ++i) {
+    DiscreteValues& x = self.assignments[i];
+    double px = self.bayesTree->evaluate(x);
+    for (size_t i = 0; i < 15; i++)
+      if (x[i]) marginals[i] += px;
+  }
 
   // Check all marginals
-  DiscreteFactor::shared_ptr marginalFactor;
+  DiscreteValues all1 = self.assignments.back();
   for (size_t i = 0; i < 15; i++) {
-    marginalFactor = self.bayesTree->marginalFactor(i, EliminateDiscrete);
+    auto marginalFactor = self.bayesTree->marginalFactor(i, EliminateDiscrete);
     double actual = (*marginalFactor)(all1);
     DOUBLES_EQUAL(marginals[i], actual, 1e-9);
   }
+}
 
+/* ************************************************************************* */
+// Check a number of joint marginals.
+TEST(DiscreteBayesTree, Joints) {
+  TestFixture self;
+
+  // Calculate some marginals for DiscreteValues==all1
+  Vector marginals = Vector::Zero(15);
+  double joint_12_14 = 0, joint_9_12_14 = 0, joint_8_12_14 = 0, joint82 = 0,
+         joint12 = 0, joint24 = 0, joint45 = 0, joint46 = 0, joint_4_11 = 0;
+  for (size_t i = 0; i < self.assignments.size(); ++i) {
+    DiscreteValues& x = self.assignments[i];
+    double px = self.bayesTree->evaluate(x);
+    for (size_t i = 0; i < 15; i++)
+      if (x[i]) marginals[i] += px;
+    if (x[12] && x[14]) {
+      joint_12_14 += px;
+      if (x[9]) joint_9_12_14 += px;
+      if (x[8]) joint_8_12_14 += px;
+    }
+    if (x[2]) {
+      if (x[8]) joint82 += px;
+      if (x[1]) joint12 += px;
+    }
+    if (x[4]) {
+      if (x[2]) joint24 += px;
+      if (x[5]) joint45 += px;
+      if (x[6]) joint46 += px;
+      if (x[11]) joint_4_11 += px;
+    }
+  }
+
+  // regression tests:
+  DOUBLES_EQUAL(joint_12_14, 0.1875, 1e-9);
+  DOUBLES_EQUAL(joint_8_12_14, 0.0375, 1e-9);
+  DOUBLES_EQUAL(joint_9_12_14, 0.15, 1e-9);
+
+  DiscreteValues all1 = self.assignments.back();
   DiscreteBayesNet::shared_ptr actualJoint;
 
   // Check joint P(8, 2)
@@ -240,8 +285,8 @@ TEST(DiscreteBayesTree, ThinTree) {
 
 /* ************************************************************************* */
 TEST(DiscreteBayesTree, Dot) {
-  const TestFixture self;
+  TestFixture self;
-  string actual = self.bayesTree->dot();
+  std::string actual = self.bayesTree->dot();
   EXPECT(actual ==
          "digraph G{\n"
          "0[label=\"13, 11, 6, 7\"];\n"
@@ -268,6 +313,62 @@ TEST(DiscreteBayesTree, Dot) {
          "}");
 }
 
+/* ************************************************************************* */
+// Check that we can have a multi-frontal lookup table
+TEST(DiscreteBayesTree, Lookup) {
+  using gtsam::symbol_shorthand::A;
+  using gtsam::symbol_shorthand::X;
+
+  // Make a small planning-like graph: 3 states, 2 actions
+  DiscreteFactorGraph graph;
+  const DiscreteKey x1{X(1), 3}, x2{X(2), 3}, x3{X(3), 3};
+  const DiscreteKey a1{A(1), 2}, a2{A(2), 2};
+
+  // Constraint on start and goal
+  graph.add(DiscreteKeys{x1}, std::vector<double>{1, 0, 0});
+  graph.add(DiscreteKeys{x3}, std::vector<double>{0, 0, 1});
+
+  // Should I stay or should I go?
+  // "Reward" (exp(-cost)) for an action is 10, and rewards multiply:
+  const double r = 10;
+  std::vector<double> table{
+      r, 0, 0, 0, r, 0,  // x1 = 0
+      0, r, 0, 0, 0, r,  // x1 = 1
+      0, 0, r, 0, 0, r   // x1 = 2
+  };
+  graph.add(DiscreteKeys{x1, a1, x2}, table);
+  graph.add(DiscreteKeys{x2, a2, x3}, table);
+
+  // eliminate for MPE (maximum probable explanation).
+  Ordering ordering{A(2), X(3), X(1), A(1), X(2)};
+  auto lookup = graph.eliminateMultifrontal(ordering, EliminateForMPE);
+
+  // Check that the lookup table is correct
+  EXPECT_LONGS_EQUAL(2, lookup->size());
+  auto lookup_x1_a1_x2 = (*lookup)[X(1)]->conditional();
+  EXPECT_LONGS_EQUAL(3, lookup_x1_a1_x2->frontals().size());
+  // check that sum is 1.0 (not 100, as we now normalize)
+  DiscreteValues empty;
+  EXPECT_DOUBLES_EQUAL(1.0, (*lookup_x1_a1_x2->sum(3))(empty), 1e-9);
+  // And that only non-zero reward is for x1 a1 x2 == 0 1 1
+  EXPECT_DOUBLES_EQUAL(1.0, (*lookup_x1_a1_x2)({{X(1),0},{A(1),1},{X(2),1}}), 1e-9);
+
+  auto lookup_a2_x3 = (*lookup)[X(3)]->conditional();
+  // check that the sum depends on x2 and is non-zero only for x2 \in {1,2}
+  auto sum_x2 = lookup_a2_x3->sum(2);
+  EXPECT_DOUBLES_EQUAL(0, (*sum_x2)({{X(2),0}}), 1e-9);
+  EXPECT_DOUBLES_EQUAL(1.0, (*sum_x2)({{X(2),1}}), 1e-9);
+  EXPECT_DOUBLES_EQUAL(2.0, (*sum_x2)({{X(2),2}}), 1e-9);
+  EXPECT_LONGS_EQUAL(2, lookup_a2_x3->frontals().size());
+  // And that the non-zero rewards are for 
+  // x2 a2 x3 == 1 1 2
+  EXPECT_DOUBLES_EQUAL(1.0, (*lookup_a2_x3)({{X(2),1},{A(2),1},{X(3),2}}), 1e-9);
+  // x2 a2 x3 == 2 0 2
+  EXPECT_DOUBLES_EQUAL(1.0, (*lookup_a2_x3)({{X(2),2},{A(2),0},{X(3),2}}), 1e-9);
+  // x2 a2 x3 == 2 1 2
+  EXPECT_DOUBLES_EQUAL(1.0, (*lookup_a2_x3)({{X(2),2},{A(2),1},{X(3),2}}), 1e-9);
+}
+
 /* ************************************************************************* */
 int main() {
   TestResult tr;

gtsam/geometry/tests/testRot3.cpp

@@ -597,6 +597,25 @@ TEST(Rot3, quaternion) {
   EXPECT(assert_equal(expected2, actual2));
 }
 
+/* ************************************************************************* */
+TEST(Rot3, ConvertQuaternion) {
+  Eigen::Quaterniond eigenQuaternion;
+  eigenQuaternion.w() = 1.0;
+  eigenQuaternion.x() = 2.0;
+  eigenQuaternion.y() = 3.0;
+  eigenQuaternion.z() = 4.0;
+  EXPECT_DOUBLES_EQUAL(1, eigenQuaternion.w(), 1e-9);
+  EXPECT_DOUBLES_EQUAL(2, eigenQuaternion.x(), 1e-9);
+  EXPECT_DOUBLES_EQUAL(3, eigenQuaternion.y(), 1e-9);
+  EXPECT_DOUBLES_EQUAL(4, eigenQuaternion.z(), 1e-9);
+
+  Rot3 R(eigenQuaternion);
+  EXPECT_DOUBLES_EQUAL(1, R.toQuaternion().w(), 1e-9);
+  EXPECT_DOUBLES_EQUAL(2, R.toQuaternion().x(), 1e-9);
+  EXPECT_DOUBLES_EQUAL(3, R.toQuaternion().y(), 1e-9);
+  EXPECT_DOUBLES_EQUAL(4, R.toQuaternion().z(), 1e-9);
+}
+
 /* ************************************************************************* */
 Matrix Cayley(const Matrix& A) {
   Matrix::Index n = A.cols();

gtsam/hybrid/HybridBayesNet.cpp

@@ -37,24 +37,6 @@ bool HybridBayesNet::equals(const This &bn, double tol) const {
   return Base::equals(bn, tol);
 }
 
-/* ************************************************************************* */
-DecisionTreeFactor::shared_ptr HybridBayesNet::discreteConditionals() const {
-  AlgebraicDecisionTree<Key> discreteProbs;
-
-  // The canonical decision tree factor which will get
-  // the discrete conditionals added to it.
-  DecisionTreeFactor discreteProbsFactor;
-
-  for (auto &&conditional : *this) {
-    if (conditional->isDiscrete()) {
-      // Convert to a DecisionTreeFactor and add it to the main factor.
-      DecisionTreeFactor f(*conditional->asDiscrete());
-      discreteProbsFactor = discreteProbsFactor * f;
-    }
-  }
-  return std::make_shared<DecisionTreeFactor>(discreteProbsFactor);
-}
-
 /* ************************************************************************* */
 /**
  * @brief Helper function to get the pruner functional.
@@ -144,53 +126,52 @@ std::function<double(const Assignment<Key> &, double)> prunerFunc(
 }
 
 /* ************************************************************************* */
-void HybridBayesNet::updateDiscreteConditionals(
+DecisionTreeFactor HybridBayesNet::pruneDiscreteConditionals(
-    const DecisionTreeFactor &prunedDiscreteProbs) {
+    size_t maxNrLeaves) {
-  KeyVector prunedTreeKeys = prunedDiscreteProbs.keys();
+  // Get the joint distribution of only the discrete keys
+  gttic_(HybridBayesNet_PruneDiscreteConditionals);
+  // The joint discrete probability.
+  DiscreteConditional discreteProbs;
+
+  std::vector<size_t> discrete_factor_idxs;
+  // Record frontal keys so we can maintain ordering
+  Ordering discrete_frontals;
 
-  // Loop with index since we need it later.
   for (size_t i = 0; i < this->size(); i++) {
-    HybridConditional::shared_ptr conditional = this->at(i);
+    auto conditional = this->at(i);
     if (conditional->isDiscrete()) {
-      auto discrete = conditional->asDiscrete();
+      discreteProbs = discreteProbs * (*conditional->asDiscrete());
 
-      // Convert pointer from conditional to factor
+      Ordering conditional_keys(conditional->frontals());
-      auto discreteTree =
+      discrete_frontals += conditional_keys;
-          std::dynamic_pointer_cast<DecisionTreeFactor::ADT>(discrete);
+      discrete_factor_idxs.push_back(i);
-      // Apply prunerFunc to the underlying AlgebraicDecisionTree
-      DecisionTreeFactor::ADT prunedDiscreteTree =
-          discreteTree->apply(prunerFunc(prunedDiscreteProbs, *conditional));
-
-      gttic_(HybridBayesNet_MakeConditional);
-      // Create the new (hybrid) conditional
-      KeyVector frontals(discrete->frontals().begin(),
-                         discrete->frontals().end());
-      auto prunedDiscrete = std::make_shared<DiscreteLookupTable>(
-          frontals.size(), conditional->discreteKeys(), prunedDiscreteTree);
-      conditional = std::make_shared<HybridConditional>(prunedDiscrete);
-      gttoc_(HybridBayesNet_MakeConditional);
-
-      // Add it back to the BayesNet
-      this->at(i) = conditional;
     }
   }
+  const DecisionTreeFactor prunedDiscreteProbs =
+      discreteProbs.prune(maxNrLeaves);
+  gttoc_(HybridBayesNet_PruneDiscreteConditionals);
+
+  // Eliminate joint probability back into conditionals
+  gttic_(HybridBayesNet_UpdateDiscreteConditionals);
+  DiscreteFactorGraph dfg{prunedDiscreteProbs};
+  DiscreteBayesNet::shared_ptr dbn = dfg.eliminateSequential(discrete_frontals);
+
+  // Assign pruned discrete conditionals back at the correct indices.
+  for (size_t i = 0; i < discrete_factor_idxs.size(); i++) {
+    size_t idx = discrete_factor_idxs.at(i);
+    this->at(idx) = std::make_shared<HybridConditional>(dbn->at(i));
+  }
+  gttoc_(HybridBayesNet_UpdateDiscreteConditionals);
+
+  return prunedDiscreteProbs;
 }
 
 /* ************************************************************************* */
 HybridBayesNet HybridBayesNet::prune(size_t maxNrLeaves) {
-  // Get the decision tree of only the discrete keys
+  DecisionTreeFactor prunedDiscreteProbs =
-  gttic_(HybridBayesNet_PruneDiscreteConditionals);
+      this->pruneDiscreteConditionals(maxNrLeaves);
-  DecisionTreeFactor::shared_ptr discreteConditionals =
-      this->discreteConditionals();
-  const DecisionTreeFactor prunedDiscreteProbs =
-      discreteConditionals->prune(maxNrLeaves);
-  gttoc_(HybridBayesNet_PruneDiscreteConditionals);
 
-  gttic_(HybridBayesNet_UpdateDiscreteConditionals);
+  /* To prune, we visitWith every leaf in the GaussianMixture.
-  this->updateDiscreteConditionals(prunedDiscreteProbs);
-  gttoc_(HybridBayesNet_UpdateDiscreteConditionals);
-
-  /* To Prune, we visitWith every leaf in the GaussianMixture.
    * For each leaf, using the assignment we can check the discrete decision tree
    * for 0.0 probability, then just set the leaf to a nullptr.
    *

gtsam/hybrid/HybridBayesNet.h

@@ -136,13 +136,6 @@ class GTSAM_EXPORT HybridBayesNet : public BayesNet<HybridConditional> {
    */
   VectorValues optimize(const DiscreteValues &assignment) const;
 
-  /**
-   * @brief Get all the discrete conditionals as a decision tree factor.
-   *
-   * @return DecisionTreeFactor::shared_ptr
-   */
-  DecisionTreeFactor::shared_ptr discreteConditionals() const;
-
   /**
    * @brief Sample from an incomplete BayesNet, given missing variables.
    *
@@ -222,12 +215,11 @@ class GTSAM_EXPORT HybridBayesNet : public BayesNet<HybridConditional> {
 
  private:
   /**
-   * @brief Update the discrete conditionals with the pruned versions.
+   * @brief Prune all the discrete conditionals.
    *
-   * @param prunedDiscreteProbs
+   * @param maxNrLeaves
    */
-  void updateDiscreteConditionals(
+  DecisionTreeFactor pruneDiscreteConditionals(size_t maxNrLeaves);
-      const DecisionTreeFactor &prunedDiscreteProbs);
 
 #ifdef GTSAM_ENABLE_BOOST_SERIALIZATION
   /** Serialization function */

gtsam/hybrid/HybridFactor.h

@@ -20,6 +20,7 @@
 #include <gtsam/base/Testable.h>
 #include <gtsam/discrete/DecisionTree.h>
 #include <gtsam/discrete/DiscreteKey.h>
+#include <gtsam/discrete/TableFactor.h>
 #include <gtsam/inference/Factor.h>
 #include <gtsam/linear/GaussianFactorGraph.h>
 #include <gtsam/nonlinear/Values.h>

gtsam/hybrid/HybridFactorGraph.cpp

@@ -17,7 +17,6 @@
  * @date   January, 2023
  */
 
-#include <gtsam/discrete/DecisionTreeFactor.h>
 #include <gtsam/hybrid/HybridFactorGraph.h>
 
 namespace gtsam {
@@ -26,7 +25,7 @@ namespace gtsam {
 std::set<DiscreteKey> HybridFactorGraph::discreteKeys() const {
   std::set<DiscreteKey> keys;
   for (auto& factor : factors_) {
-    if (auto p = std::dynamic_pointer_cast<DecisionTreeFactor>(factor)) {
+    if (auto p = std::dynamic_pointer_cast<DiscreteFactor>(factor)) {
       for (const DiscreteKey& key : p->discreteKeys()) {
         keys.insert(key);
       }
@@ -67,6 +66,8 @@ const KeySet HybridFactorGraph::continuousKeySet() const {
       for (const Key& key : p->continuousKeys()) {
         keys.insert(key);
       }
+    } else if (auto p = std::dynamic_pointer_cast<GaussianFactor>(factor)) {
+      keys.insert(p->keys().begin(), p->keys().end());
     }
   }
   return keys;

gtsam/hybrid/HybridGaussianFactorGraph.cpp

@@ -48,8 +48,6 @@
 #include <utility>
 #include <vector>
 
-// #define HYBRID_TIMING
-
 namespace gtsam {
 
 /// Specialize EliminateableFactorGraph for HybridGaussianFactorGraph:
@@ -120,7 +118,7 @@ GaussianFactorGraphTree HybridGaussianFactorGraph::assembleGraphTree() const {
         // TODO(dellaert): in C++20, we can use std::visit.
         continue;
       }
-    } else if (dynamic_pointer_cast<DecisionTreeFactor>(f)) {
+    } else if (dynamic_pointer_cast<DiscreteFactor>(f)) {
       // Don't do anything for discrete-only factors
       // since we want to eliminate continuous values only.
       continue;
@@ -167,8 +165,8 @@ discreteElimination(const HybridGaussianFactorGraph &factors,
   DiscreteFactorGraph dfg;
 
   for (auto &f : factors) {
-    if (auto dtf = dynamic_pointer_cast<DecisionTreeFactor>(f)) {
+    if (auto df = dynamic_pointer_cast<DiscreteFactor>(f)) {
-      dfg.push_back(dtf);
+      dfg.push_back(df);
     } else if (auto orphan = dynamic_pointer_cast<OrphanWrapper>(f)) {
       // Ignore orphaned clique.
       // TODO(dellaert): is this correct? If so explain here.
@@ -231,17 +229,7 @@ hybridElimination(const HybridGaussianFactorGraph &factors,
       return {nullptr, nullptr};
     }
 
-#ifdef HYBRID_TIMING
-    gttic_(hybrid_eliminate);
-#endif
-
-    gttic_(hybrid_continuous_eliminate);
     auto result = EliminatePreferCholesky(graph, frontalKeys);
-    gttoc_(hybrid_continuous_eliminate);
-
-#ifdef HYBRID_TIMING
-    gttoc_(hybrid_eliminate);
-#endif
 
     return result;
   };
@@ -359,64 +347,68 @@ EliminateHybrid(const HybridGaussianFactorGraph &factors,
   // When the number of assignments is large we may encounter stack overflows.
   // However this is also the case with iSAM2, so no pressure :)
 
-  // PREPROCESS: Identify the nature of the current elimination
+  // Check the factors:
-
-  // TODO(dellaert): just check the factors:
   // 1. if all factors are discrete, then we can do discrete elimination:
   // 2. if all factors are continuous, then we can do continuous elimination:
   // 3. if not, we do hybrid elimination:
 
-  // First, identify the separator keys, i.e. all keys that are not frontal.
+  bool only_discrete = true, only_continuous = true;
-  KeySet separatorKeys;
   for (auto &&factor : factors) {
-    separatorKeys.insert(factor->begin(), factor->end());
+    if (auto hybrid_factor = std::dynamic_pointer_cast<HybridFactor>(factor)) {
-  }
+      if (hybrid_factor->isDiscrete()) {
-  // remove frontals from separator
+        only_continuous = false;
-  for (auto &k : frontalKeys) {
+      } else if (hybrid_factor->isContinuous()) {
-    separatorKeys.erase(k);
+        only_discrete = false;
-  }
+      } else if (hybrid_factor->isHybrid()) {
-
+        only_continuous = false;
-  // Build a map from keys to DiscreteKeys
+        only_discrete = false;
-  auto mapFromKeyToDiscreteKey = factors.discreteKeyMap();
+      }
-
+    } else if (auto cont_factor =
-  // Fill in discrete frontals and continuous frontals.
+                   std::dynamic_pointer_cast<GaussianFactor>(factor)) {
-  std::set<DiscreteKey> discreteFrontals;
+      only_discrete = false;
-  KeySet continuousFrontals;
+    } else if (auto discrete_factor =
-  for (auto &k : frontalKeys) {
+                   std::dynamic_pointer_cast<DiscreteFactor>(factor)) {
-    if (mapFromKeyToDiscreteKey.find(k) != mapFromKeyToDiscreteKey.end()) {
+      only_continuous = false;
-      discreteFrontals.insert(mapFromKeyToDiscreteKey.at(k));
-    } else {
-      continuousFrontals.insert(k);
     }
   }
 
-  // Fill in discrete discrete separator keys and continuous separator keys.
-  std::set<DiscreteKey> discreteSeparatorSet;
-  KeyVector continuousSeparator;
-  for (auto &k : separatorKeys) {
-    if (mapFromKeyToDiscreteKey.find(k) != mapFromKeyToDiscreteKey.end()) {
-      discreteSeparatorSet.insert(mapFromKeyToDiscreteKey.at(k));
-    } else {
-      continuousSeparator.push_back(k);
-    }
-  }
-
-  // Check if we have any continuous keys:
-  const bool discrete_only =
-      continuousFrontals.empty() && continuousSeparator.empty();
-
   // NOTE: We should really defer the product here because of pruning
 
-  if (discrete_only) {
+  if (only_discrete) {
     // Case 1: we are only dealing with discrete
     return discreteElimination(factors, frontalKeys);
-  } else if (mapFromKeyToDiscreteKey.empty()) {
+  } else if (only_continuous) {
     // Case 2: we are only dealing with continuous
     return continuousElimination(factors, frontalKeys);
   } else {
     // Case 3: We are now in the hybrid land!
+    KeySet frontalKeysSet(frontalKeys.begin(), frontalKeys.end());
+
+    // Find all the keys in the set of continuous keys
+    // which are not in the frontal keys. This is our continuous separator.
+    KeyVector continuousSeparator;
+    auto continuousKeySet = factors.continuousKeySet();
+    std::set_difference(
+        continuousKeySet.begin(), continuousKeySet.end(),
+        frontalKeysSet.begin(), frontalKeysSet.end(),
+        std::inserter(continuousSeparator, continuousSeparator.begin()));
+
+    // Similarly for the discrete separator.
+    KeySet discreteSeparatorSet;
+    std::set<DiscreteKey> discreteSeparator;
+    auto discreteKeySet = factors.discreteKeySet();
+    std::set_difference(
+        discreteKeySet.begin(), discreteKeySet.end(), frontalKeysSet.begin(),
+        frontalKeysSet.end(),
+        std::inserter(discreteSeparatorSet, discreteSeparatorSet.begin()));
+    // Convert from set of keys to set of DiscreteKeys
+    auto discreteKeyMap = factors.discreteKeyMap();
+    for (auto key : discreteSeparatorSet) {
+      discreteSeparator.insert(discreteKeyMap.at(key));
+    }
+
     return hybridElimination(factors, frontalKeys, continuousSeparator,
-                             discreteSeparatorSet);
+                             discreteSeparator);
   }
 }
 
@@ -440,7 +432,7 @@ AlgebraicDecisionTree<Key> HybridGaussianFactorGraph::error(
       // Add the gaussian factor error to every leaf of the error tree.
       error_tree = error_tree.apply(
           [error](double leaf_value) { return leaf_value + error; });
-    } else if (dynamic_pointer_cast<DecisionTreeFactor>(f)) {
+    } else if (dynamic_pointer_cast<DiscreteFactor>(f)) {
       // If factor at `idx` is discrete-only, we skip.
       continue;
     } else {

gtsam/hybrid/HybridGaussianFactorGraph.h

@@ -40,6 +40,7 @@ class HybridEliminationTree;
 class HybridBayesTree;
 class HybridJunctionTree;
 class DecisionTreeFactor;
+class TableFactor;
 class JacobianFactor;
 class HybridValues;
 

gtsam/hybrid/HybridJunctionTree.cpp

@@ -66,7 +66,7 @@ struct HybridConstructorTraversalData {
         for (auto& k : hf->discreteKeys()) {
           data.discreteKeys.insert(k.first);
         }
-      } else if (auto hf = std::dynamic_pointer_cast<DecisionTreeFactor>(f)) {
+      } else if (auto hf = std::dynamic_pointer_cast<DiscreteFactor>(f)) {
         for (auto& k : hf->discreteKeys()) {
           data.discreteKeys.insert(k.first);
         }
@@ -161,7 +161,7 @@ HybridJunctionTree::HybridJunctionTree(
   Data rootData(0);
   rootData.junctionTreeNode =
       std::make_shared<typename Base::Node>();  // Make a dummy node to gather
-                                                  // the junction tree roots
+                                                // the junction tree roots
   treeTraversal::DepthFirstForest(eliminationTree, rootData,
                                   Data::ConstructorTraversalVisitorPre,
                                   Data::ConstructorTraversalVisitorPost);

gtsam/hybrid/HybridNonlinearFactorGraph.cpp

@@ -17,6 +17,7 @@
  */
 
 #include <gtsam/discrete/DecisionTreeFactor.h>
+#include <gtsam/discrete/TableFactor.h>
 #include <gtsam/hybrid/GaussianMixture.h>
 #include <gtsam/hybrid/HybridGaussianFactorGraph.h>
 #include <gtsam/hybrid/HybridNonlinearFactorGraph.h>
@@ -67,7 +68,7 @@ HybridGaussianFactorGraph::shared_ptr HybridNonlinearFactorGraph::linearize(
     } else if (auto nlf = dynamic_pointer_cast<NonlinearFactor>(f)) {
       const GaussianFactor::shared_ptr& gf = nlf->linearize(continuousValues);
       linearFG->push_back(gf);
-    } else if (dynamic_pointer_cast<DecisionTreeFactor>(f)) {
+    } else if (dynamic_pointer_cast<DiscreteFactor>(f)) {
       // If discrete-only: doesn't need linearization.
       linearFG->push_back(f);
     } else if (auto gmf = dynamic_pointer_cast<GaussianMixtureFactor>(f)) {

gtsam/hybrid/HybridSmoother.cpp

@@ -72,7 +72,8 @@ void HybridSmoother::update(HybridGaussianFactorGraph graph,
       addConditionals(graph, hybridBayesNet_, ordering);
 
   // Eliminate.
-  auto bayesNetFragment = graph.eliminateSequential(ordering);
+  HybridBayesNet::shared_ptr bayesNetFragment =
+      graph.eliminateSequential(ordering);
 
   /// Prune
   if (maxNrLeaves) {
@@ -96,7 +97,8 @@ HybridSmoother::addConditionals(const HybridGaussianFactorGraph &originalGraph,
   HybridGaussianFactorGraph graph(originalGraph);
   HybridBayesNet hybridBayesNet(originalHybridBayesNet);
 
-  // If we are not at the first iteration, means we have conditionals to add.
+  // If hybridBayesNet is not empty,
+  // it means we have conditionals to add to the factor graph.
   if (!hybridBayesNet.empty()) {
     // We add all relevant conditional mixtures on the last continuous variable
     // in the previous `hybridBayesNet` to the graph

gtsam/hybrid/hybrid.i

@@ -35,14 +35,11 @@ class HybridValues {
 };
 
 #include <gtsam/hybrid/HybridFactor.h>
-virtual class HybridFactor {
+virtual class HybridFactor : gtsam::Factor {
   void print(string s = "HybridFactor\n",
              const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::HybridFactor& other, double tol = 1e-9) const;
-  bool empty() const;
-  size_t size() const;
-  gtsam::KeyVector keys() const;
 
   // Standard interface:
   double error(const gtsam::HybridValues &values) const;

gtsam/hybrid/tests/Switching.h

@@ -202,31 +202,16 @@ struct Switching {
    * @brief Add "mode chain" to HybridNonlinearFactorGraph from M(0) to M(K-2).
    * E.g. if K=4, we want M0, M1 and M2.
    *
-   * @param fg The nonlinear factor graph to which the mode chain is added.
+   * @param fg The factor graph to which the mode chain is added.
    */
-  void addModeChain(HybridNonlinearFactorGraph *fg,
+  template <typename FACTORGRAPH>
+  void addModeChain(FACTORGRAPH *fg,
                     std::string discrete_transition_prob = "1/2 3/2") {
-    fg->emplace_shared<DiscreteDistribution>(modes[0], "1/1");
+    fg->template emplace_shared<DiscreteDistribution>(modes[0], "1/1");
     for (size_t k = 0; k < K - 2; k++) {
       auto parents = {modes[k]};
-      fg->emplace_shared<DiscreteConditional>(modes[k + 1], parents,
+      fg->template emplace_shared<DiscreteConditional>(
-                                              discrete_transition_prob);
+          modes[k + 1], parents, discrete_transition_prob);
-    }
-  }
-
-  /**
-   * @brief Add "mode chain" to HybridGaussianFactorGraph from M(0) to M(K-2).
-   * E.g. if K=4, we want M0, M1 and M2.
-   *
-   * @param fg The gaussian factor graph to which the mode chain is added.
-   */
-  void addModeChain(HybridGaussianFactorGraph *fg,
-                    std::string discrete_transition_prob = "1/2 3/2") {
-    fg->emplace_shared<DiscreteDistribution>(modes[0], "1/1");
-    for (size_t k = 0; k < K - 2; k++) {
-      auto parents = {modes[k]};
-      fg->emplace_shared<DiscreteConditional>(modes[k + 1], parents,
-                                              discrete_transition_prob);
     }
   }
 };

gtsam/hybrid/tests/testGaussianMixtureFactor.cpp

@@ -108,7 +108,7 @@ TEST(GaussianMixtureFactor, Printing) {
   std::string expected =
       R"(Hybrid [x1 x2; 1]{
  Choice(1) 
- 0 Leaf :
+ 0 Leaf [1] :
   A[x1] = [
 	0;
 	0
@@ -120,7 +120,7 @@ TEST(GaussianMixtureFactor, Printing) {
   b = [ 0 0 ]
   No noise model
 
- 1 Leaf :
+ 1 Leaf [1] :
   A[x1] = [
 	0;
 	0

gtsam/hybrid/tests/testHybridBayesNet.cpp

@@ -231,7 +231,7 @@ TEST(HybridBayesNet, Pruning) {
   auto prunedTree = prunedBayesNet.evaluate(delta.continuous());
 
   // Regression test on pruned logProbability tree
-  std::vector<double> pruned_leaves = {0.0, 20.346113, 0.0, 19.738098};
+  std::vector<double> pruned_leaves = {0.0, 32.713418, 0.0, 31.735823};
   AlgebraicDecisionTree<Key> expected_pruned(discrete_keys, pruned_leaves);
   EXPECT(assert_equal(expected_pruned, prunedTree, 1e-6));
 
@@ -248,8 +248,10 @@ TEST(HybridBayesNet, Pruning) {
   logProbability +=
       posterior->at(4)->asDiscrete()->logProbability(hybridValues);
 
+  // Regression
   double density = exp(logProbability);
-  EXPECT_DOUBLES_EQUAL(density, actualTree(discrete_values), 1e-9);
+  EXPECT_DOUBLES_EQUAL(density,
+                       1.6078460548731697 * actualTree(discrete_values), 1e-6);
   EXPECT_DOUBLES_EQUAL(density, prunedTree(discrete_values), 1e-9);
   EXPECT_DOUBLES_EQUAL(logProbability, posterior->logProbability(hybridValues),
                        1e-9);
@@ -283,20 +285,30 @@ TEST(HybridBayesNet, UpdateDiscreteConditionals) {
   EXPECT_LONGS_EQUAL(7, posterior->size());
 
   size_t maxNrLeaves = 3;
-  auto discreteConditionals = posterior->discreteConditionals();
+  DiscreteConditional discreteConditionals;
+  for (auto&& conditional : *posterior) {
+    if (conditional->isDiscrete()) {
+      discreteConditionals =
+          discreteConditionals * (*conditional->asDiscrete());
+    }
+  }
   const DecisionTreeFactor::shared_ptr prunedDecisionTree =
       std::make_shared<DecisionTreeFactor>(
-          discreteConditionals->prune(maxNrLeaves));
+          discreteConditionals.prune(maxNrLeaves));
 
   EXPECT_LONGS_EQUAL(maxNrLeaves + 2 /*2 zero leaves*/,
                      prunedDecisionTree->nrLeaves());
 
-  auto original_discrete_conditionals = *(posterior->at(4)->asDiscrete());
+  // regression
+  DiscreteKeys dkeys{{M(0), 2}, {M(1), 2}, {M(2), 2}};
+  DecisionTreeFactor::ADT potentials(
+      dkeys, std::vector<double>{0, 0, 0, 0.505145423, 0, 1, 0, 0.494854577});
+  DiscreteConditional expected_discrete_conditionals(1, dkeys, potentials);
 
   // Prune!
   posterior->prune(maxNrLeaves);
 
-  // Functor to verify values against the original_discrete_conditionals
+  // Functor to verify values against the expected_discrete_conditionals
   auto checker = [&](const Assignment<Key>& assignment,
                      double probability) -> double {
     // typecast so we can use this to get probability value
@@ -304,7 +316,7 @@ TEST(HybridBayesNet, UpdateDiscreteConditionals) {
     if (prunedDecisionTree->operator()(choices) == 0) {
       EXPECT_DOUBLES_EQUAL(0.0, probability, 1e-9);
     } else {
-      EXPECT_DOUBLES_EQUAL(original_discrete_conditionals(choices), probability,
+      EXPECT_DOUBLES_EQUAL(expected_discrete_conditionals(choices), probability,
                            1e-9);
     }
     return 0.0;

gtsam/hybrid/tests/testHybridBayesTree.cpp

@@ -146,7 +146,7 @@ TEST(HybridBayesTree, Optimize) {
 
   DiscreteFactorGraph dfg;
   for (auto&& f : *remainingFactorGraph) {
-    auto discreteFactor = dynamic_pointer_cast<DecisionTreeFactor>(f);
+    auto discreteFactor = dynamic_pointer_cast<DiscreteFactor>(f);
     assert(discreteFactor);
     dfg.push_back(discreteFactor);
   }

gtsam/hybrid/tests/testHybridEstimation.cpp

@@ -140,6 +140,61 @@ TEST(HybridEstimation, IncrementalSmoother) {
   EXPECT(assert_equal(expected_continuous, result));
 }
 
+/****************************************************************************/
+// Test approximate inference with an additional pruning step.
+TEST(HybridEstimation, ISAM) {
+  size_t K = 15;
+  std::vector<double> measurements = {0, 1, 2, 2, 2, 2,  3,  4,  5,  6, 6,
+                                      7, 8, 9, 9, 9, 10, 11, 11, 11, 11};
+  // Ground truth discrete seq
+  std::vector<size_t> discrete_seq = {1, 1, 0, 0, 0, 1, 1, 1, 1, 0,
+                                      1, 1, 1, 0, 0, 1, 1, 0, 0, 0};
+  // Switching example of robot moving in 1D
+  // with given measurements and equal mode priors.
+  Switching switching(K, 1.0, 0.1, measurements, "1/1 1/1");
+  HybridNonlinearISAM isam;
+  HybridNonlinearFactorGraph graph;
+  Values initial;
+
+  // gttic_(Estimation);
+
+  // Add the X(0) prior
+  graph.push_back(switching.nonlinearFactorGraph.at(0));
+  initial.insert(X(0), switching.linearizationPoint.at<double>(X(0)));
+
+  HybridGaussianFactorGraph linearized;
+
+  for (size_t k = 1; k < K; k++) {
+    // Motion Model
+    graph.push_back(switching.nonlinearFactorGraph.at(k));
+    // Measurement
+    graph.push_back(switching.nonlinearFactorGraph.at(k + K - 1));
+
+    initial.insert(X(k), switching.linearizationPoint.at<double>(X(k)));
+
+    isam.update(graph, initial, 3);
+    // isam.bayesTree().print("\n\n");
+
+    graph.resize(0);
+    initial.clear();
+  }
+
+  Values result = isam.estimate();
+  DiscreteValues assignment = isam.assignment();
+
+  DiscreteValues expected_discrete;
+  for (size_t k = 0; k < K - 1; k++) {
+    expected_discrete[M(k)] = discrete_seq[k];
+  }
+  EXPECT(assert_equal(expected_discrete, assignment));
+
+  Values expected_continuous;
+  for (size_t k = 0; k < K; k++) {
+    expected_continuous.insert(X(k), measurements[k]);
+  }
+  EXPECT(assert_equal(expected_continuous, result));
+}
+
 /**
  * @brief A function to get a specific 1D robot motion problem as a linearized
  * factor graph. This is the problem P(X|Z, M), i.e. estimating the continuous

gtsam/hybrid/tests/testHybridFactorGraph.cpp

@@ -18,7 +18,9 @@
 #include <gtsam/base/TestableAssertions.h>
 #include <gtsam/base/utilities.h>
 #include <gtsam/hybrid/HybridFactorGraph.h>
+#include <gtsam/hybrid/HybridGaussianFactorGraph.h>
 #include <gtsam/inference/Symbol.h>
+#include <gtsam/linear/JacobianFactor.h>
 #include <gtsam/nonlinear/PriorFactor.h>
 
 using namespace std;
@@ -37,6 +39,32 @@ TEST(HybridFactorGraph, Constructor) {
   HybridFactorGraph fg;
 }
 
+/* ************************************************************************* */
+// Test if methods to get keys work as expected.
+TEST(HybridFactorGraph, Keys) {
+  HybridGaussianFactorGraph hfg;
+
+  // Add prior on x0
+  hfg.add(JacobianFactor(X(0), I_3x3, Z_3x1));
+
+  // Add factor between x0 and x1
+  hfg.add(JacobianFactor(X(0), I_3x3, X(1), -I_3x3, Z_3x1));
+
+  // Add a gaussian mixture factor ϕ(x1, c1)
+  DiscreteKey m1(M(1), 2);
+  DecisionTree<Key, GaussianFactor::shared_ptr> dt(
+      M(1), std::make_shared<JacobianFactor>(X(1), I_3x3, Z_3x1),
+      std::make_shared<JacobianFactor>(X(1), I_3x3, Vector3::Ones()));
+  hfg.add(GaussianMixtureFactor({X(1)}, {m1}, dt));
+
+  KeySet expected_continuous{X(0), X(1)};
+  EXPECT(
+      assert_container_equality(expected_continuous, hfg.continuousKeySet()));
+
+  KeySet expected_discrete{M(1)};
+  EXPECT(assert_container_equality(expected_discrete, hfg.discreteKeySet()));
+}
+
 /* ************************************************************************* */
 int main() {
   TestResult tr;

gtsam/hybrid/tests/testHybridGaussianFactorGraph.cpp

@@ -902,7 +902,7 @@ TEST(HybridGaussianFactorGraph, EliminateSwitchingNetwork) {
   // Test resulting posterior Bayes net has correct size:
   EXPECT_LONGS_EQUAL(8, posterior->size());
 
-  // TODO(dellaert): this test fails - no idea why.
+  // Ratio test
   EXPECT(ratioTest(bn, measurements, *posterior));
 }
 

gtsam/hybrid/tests/testHybridNonlinearFactorGraph.cpp

@@ -492,7 +492,7 @@ factor 0:
 factor 1: 
 Hybrid [x0 x1; m0]{
  Choice(m0) 
- 0 Leaf :
+ 0 Leaf [1] :
   A[x0] = [
 	-1
 ]
@@ -502,7 +502,7 @@ Hybrid [x0 x1; m0]{
   b = [ -1 ]
   No noise model
 
- 1 Leaf :
+ 1 Leaf [1] :
   A[x0] = [
 	-1
 ]
@@ -516,7 +516,7 @@ Hybrid [x0 x1; m0]{
 factor 2: 
 Hybrid [x1 x2; m1]{
  Choice(m1) 
- 0 Leaf :
+ 0 Leaf [1] :
   A[x1] = [
 	-1
 ]
@@ -526,7 +526,7 @@ Hybrid [x1 x2; m1]{
   b = [ -1 ]
   No noise model
 
- 1 Leaf :
+ 1 Leaf [1] :
   A[x1] = [
 	-1
 ]
@@ -550,16 +550,16 @@ factor 4:
   b = [ -10 ]
   No noise model
 factor 5:  P( m0 ):
- Leaf  0.5
+ Leaf [2]  0.5
 
 factor 6:  P( m1 | m0 ):
  Choice(m1) 
  0 Choice(m0) 
- 0 0 Leaf 0.33333333
+ 0 0 Leaf [1] 0.33333333
- 0 1 Leaf  0.6
+ 0 1 Leaf [1]  0.6
  1 Choice(m0) 
- 1 0 Leaf 0.66666667
+ 1 0 Leaf [1] 0.66666667
- 1 1 Leaf  0.4
+ 1 1 Leaf [1]  0.4
 
 )";
   EXPECT(assert_print_equal(expected_hybridFactorGraph, linearizedFactorGraph));
@@ -570,13 +570,13 @@ size: 3
 conditional 0: Hybrid  P( x0 | x1 m0)
  Discrete Keys = (m0, 2), 
  Choice(m0) 
- 0 Leaf  p(x0 | x1)
+ 0 Leaf [1] p(x0 | x1)
   R = [ 10.0499 ]
   S[x1] = [ -0.0995037 ]
   d = [ -9.85087 ]
   No noise model
 
- 1 Leaf  p(x0 | x1)
+ 1 Leaf [1] p(x0 | x1)
   R = [ 10.0499 ]
   S[x1] = [ -0.0995037 ]
   d = [ -9.95037 ]
@@ -586,26 +586,26 @@ conditional 1: Hybrid  P( x1 | x2 m0 m1)
  Discrete Keys = (m0, 2), (m1, 2), 
  Choice(m1) 
  0 Choice(m0) 
- 0 0 Leaf  p(x1 | x2)
+ 0 0 Leaf [1] p(x1 | x2)
   R = [ 10.099 ]
   S[x2] = [ -0.0990196 ]
   d = [ -9.99901 ]
   No noise model
 
- 0 1 Leaf  p(x1 | x2)
+ 0 1 Leaf [1] p(x1 | x2)
   R = [ 10.099 ]
   S[x2] = [ -0.0990196 ]
   d = [ -9.90098 ]
   No noise model
 
  1 Choice(m0) 
- 1 0 Leaf  p(x1 | x2)
+ 1 0 Leaf [1] p(x1 | x2)
   R = [ 10.099 ]
   S[x2] = [ -0.0990196 ]
   d = [ -10.098 ]
   No noise model
 
- 1 1 Leaf  p(x1 | x2)
+ 1 1 Leaf [1] p(x1 | x2)
   R = [ 10.099 ]
   S[x2] = [ -0.0990196 ]
   d = [ -10 ]
@@ -615,14 +615,14 @@ conditional 2: Hybrid  P( x2 | m0 m1)
  Discrete Keys = (m0, 2), (m1, 2), 
  Choice(m1) 
  0 Choice(m0) 
- 0 0 Leaf  p(x2)
+ 0 0 Leaf [1] p(x2)
   R = [ 10.0494 ]
   d = [ -10.1489 ]
   mean: 1 elements
   x2: -1.0099
   No noise model
 
- 0 1 Leaf  p(x2)
+ 0 1 Leaf [1] p(x2)
   R = [ 10.0494 ]
   d = [ -10.1479 ]
   mean: 1 elements
@@ -630,14 +630,14 @@ conditional 2: Hybrid  P( x2 | m0 m1)
   No noise model
 
  1 Choice(m0) 
- 1 0 Leaf  p(x2)
+ 1 0 Leaf [1] p(x2)
   R = [ 10.0494 ]
   d = [ -10.0504 ]
   mean: 1 elements
   x2: -1.0001
   No noise model
 
- 1 1 Leaf  p(x2)
+ 1 1 Leaf [1] p(x2)
   R = [ 10.0494 ]
   d = [ -10.0494 ]
   mean: 1 elements

gtsam/hybrid/tests/testMixtureFactor.cpp

@@ -63,8 +63,8 @@ TEST(MixtureFactor, Printing) {
       R"(Hybrid [x1 x2; 1]
 MixtureFactor
  Choice(1) 
- 0 Leaf Nonlinear factor on 2 keys
+ 0 Leaf [1] Nonlinear factor on 2 keys
- 1 Leaf Nonlinear factor on 2 keys
+ 1 Leaf [1] Nonlinear factor on 2 keys
 )";
   EXPECT(assert_print_equal(expected, mixtureFactor));
 }

gtsam/inference/BayesTreeCliqueBase.h

@@ -140,9 +140,15 @@ namespace gtsam {
     /** Access the conditional */
     const sharedConditional& conditional() const { return conditional_; }
 
-    /** is this the root of a Bayes tree ? */
+    /// Return true if this clique is the root of a Bayes tree. 
     inline bool isRoot() const { return parent_.expired(); }
 
+    /// Return the number of children.
+    size_t nrChildren() const { return children.size(); }
+
+    /// Return the child at index i.
+    const derived_ptr operator[](size_t i) const { return children.at(i); }
+
     /** The size of subtree rooted at this clique, i.e., nr of Cliques */
     size_t treeSize() const;
 

gtsam/inference/ClusterTree.h

@@ -49,7 +49,7 @@ class ClusterTree {
     virtual ~Cluster() {}
 
     const Cluster& operator[](size_t i) const {
-      return *(children[i]);
+      return *(children.at(i));
     }
 
     /// Construct from factors associated with a single key
@@ -161,7 +161,7 @@ class ClusterTree {
   }
 
   const Cluster& operator[](size_t i) const {
-    return *(roots_[i]);
+    return *(roots_.at(i));
   }
 
   /// @}

gtsam/inference/EliminateableFactorGraph-inst.h

@@ -74,8 +74,9 @@ namespace gtsam {
       EliminationTreeType etree(asDerived(), (*variableIndex).get(), ordering);
       const auto [bayesNet, factorGraph] = etree.eliminate(function);
       // If any factors are remaining, the ordering was incomplete
-      if(!factorGraph->empty())
+      if(!factorGraph->empty()) {
-        throw InconsistentEliminationRequested();
+        throw InconsistentEliminationRequested(factorGraph->keys());
+      }
       // Return the Bayes net
       return bayesNet;
     }
@@ -136,8 +137,9 @@ namespace gtsam {
       JunctionTreeType junctionTree(etree);
       const auto [bayesTree, factorGraph] = junctionTree.eliminate(function);
       // If any factors are remaining, the ordering was incomplete
-      if(!factorGraph->empty())
+      if(!factorGraph->empty()) {
-        throw InconsistentEliminationRequested();
+        throw InconsistentEliminationRequested(factorGraph->keys());
+      }
       // Return the Bayes tree
       return bayesTree;
     }

gtsam/inference/EliminateableFactorGraph.h

@@ -51,12 +51,12 @@ namespace gtsam {
    *  algorithms.  Any factor graph holding eliminateable factors can derive from this class to
    *  expose functions for computing marginals, conditional marginals, doing multifrontal and
    *  sequential elimination, etc. */
-  template<class FACTORGRAPH>
+  template<class FACTOR_GRAPH>
   class EliminateableFactorGraph
   {
   private:
-    typedef EliminateableFactorGraph<FACTORGRAPH> This; ///< Typedef to this class.
+    typedef EliminateableFactorGraph<FACTOR_GRAPH> This; ///< Typedef to this class.
-    typedef FACTORGRAPH FactorGraphType; ///< Typedef to factor graph type
+    typedef FACTOR_GRAPH FactorGraphType; ///< Typedef to factor graph type
     // Base factor type stored in this graph (private because derived classes will get this from
     // their FactorGraph base class)
     typedef typename EliminationTraits<FactorGraphType>::FactorType _FactorType;

gtsam/inference/FactorGraph.h

@@ -29,10 +29,6 @@
 
 #include <Eigen/Core>  // for Eigen::aligned_allocator
 
-#ifdef GTSAM_USE_BOOST_FEATURES
-#include <boost/assign/list_inserter.hpp>
-#endif
-
 #ifdef GTSAM_ENABLE_BOOST_SERIALIZATION
 #include <boost/serialization/nvp.hpp>
 #include <boost/serialization/vector.hpp>
@@ -53,45 +49,6 @@ class BayesTree;
 
 class HybridValues;
 
-/** Helper */
-template <class C>
-class CRefCallPushBack {
-  C& obj;
-
- public:
-  explicit CRefCallPushBack(C& obj) : obj(obj) {}
-  template <typename A>
-  void operator()(const A& a) {
-    obj.push_back(a);
-  }
-};
-
-/** Helper */
-template <class C>
-class RefCallPushBack {
-  C& obj;
-
- public:
-  explicit RefCallPushBack(C& obj) : obj(obj) {}
-  template <typename A>
-  void operator()(A& a) {
-    obj.push_back(a);
-  }
-};
-
-/** Helper */
-template <class C>
-class CRefCallAddCopy {
-  C& obj;
-
- public:
-  explicit CRefCallAddCopy(C& obj) : obj(obj) {}
-  template <typename A>
-  void operator()(const A& a) {
-    obj.addCopy(a);
-  }
-};
-
 /**
  * A factor graph is a bipartite graph with factor nodes connected to variable
  * nodes. In this class, however, only factor nodes are kept around.
@@ -215,17 +172,26 @@ class FactorGraph {
     push_back(factor);
   }
 
-#ifdef GTSAM_USE_BOOST_FEATURES
+  /// Append factor to factor graph
-  /// `+=` works well with boost::assign list inserter.
   template <class DERIVEDFACTOR>
-  typename std::enable_if<
+  typename std::enable_if<std::is_base_of<FactorType, DERIVEDFACTOR>::value,
-      std::is_base_of<FactorType, DERIVEDFACTOR>::value,
+                          This>::type&
-      boost::assign::list_inserter<RefCallPushBack<This>>>::type
   operator+=(std::shared_ptr<DERIVEDFACTOR> factor) {
-    return boost::assign::make_list_inserter(RefCallPushBack<This>(*this))(
+    push_back(factor);
-        factor);
+    return *this;
+  }
+
+  /**
+   * @brief Overload comma operator to allow for append chaining.
+   *
+   * E.g. fg += factor1, factor2, ...
+   */
+  template <class DERIVEDFACTOR>
+  typename std::enable_if<std::is_base_of<FactorType, DERIVEDFACTOR>::value, This>::type& operator,(
+      std::shared_ptr<DERIVEDFACTOR> factor) {
+    push_back(factor);
+    return *this;
   }
-#endif
 
   /// @}
   /// @name Adding via iterators
@@ -276,18 +242,15 @@ class FactorGraph {
     push_back(factorOrContainer);
   }
 
-#ifdef GTSAM_USE_BOOST_FEATURES
   /**
    * Add a factor or container of factors, including STL collections,
    * BayesTrees, etc.
    */
   template <class FACTOR_OR_CONTAINER>
-  boost::assign::list_inserter<CRefCallPushBack<This>> operator+=(
+  This& operator+=(const FACTOR_OR_CONTAINER& factorOrContainer) {
-      const FACTOR_OR_CONTAINER& factorOrContainer) {
+    push_back(factorOrContainer);
-    return boost::assign::make_list_inserter(CRefCallPushBack<This>(*this))(
+    return *this;
-        factorOrContainer);
   }
-#endif
 
   /// @}
   /// @name Specialized versions

gtsam/inference/Ordering.cpp

@@ -281,6 +281,18 @@ void Ordering::print(const std::string& str,
   cout.flush();
 }
 
+/* ************************************************************************* */
+Ordering::This& Ordering::operator+=(Key key) {
+  this->push_back(key);
+  return *this;
+}
+
+/* ************************************************************************* */
+Ordering::This& Ordering::operator,(Key key) {
+  this->push_back(key);
+  return *this;
+}
+
 /* ************************************************************************* */
 Ordering::This& Ordering::operator+=(KeyVector& keys) {
   this->insert(this->end(), keys.begin(), keys.end());

gtsam/inference/Ordering.h

@@ -25,10 +25,6 @@
 #include <gtsam/inference/MetisIndex.h>
 #include <gtsam/base/FastSet.h>
 
-#ifdef GTSAM_USE_BOOST_FEATURES
-#include <boost/assign/list_inserter.hpp>
-#endif
-
 #include <algorithm>
 #include <vector>
 
@@ -61,15 +57,13 @@ public:
       Base(keys.begin(), keys.end()) {
   }
 
-#ifdef GTSAM_USE_BOOST_FEATURES
+  /// Add new variables to the ordering as
-  /// Add new variables to the ordering as ordering += key1, key2, ...  Equivalent to calling
+  /// `ordering += key1, key2, ...`.
-  /// push_back.
+  This& operator+=(Key key);
-  boost::assign::list_inserter<boost::assign_detail::call_push_back<This> > operator+=(
+
-      Key key) {
+  /// Overloading the comma operator allows for chaining appends
-    return boost::assign::make_list_inserter(
+  // e.g. keys += key1, key2
-        boost::assign_detail::call_push_back<This>(*this))(key);
+  This& operator,(Key key);
-  }
-#endif
 
   /**
    * @brief Append new keys to the ordering as `ordering += keys`.

gtsam/inference/inference.i

@@ -104,6 +104,7 @@ class Ordering {
   // Standard Constructors and Named Constructors
   Ordering();
   Ordering(const gtsam::Ordering& other);
+  Ordering(const std::vector<size_t>& keys);
 
   template <
       FACTOR_GRAPH = {gtsam::NonlinearFactorGraph, gtsam::DiscreteFactorGraph,
@@ -148,7 +149,7 @@ class Ordering {
 
   // Standard interface
   size_t size() const;
-  size_t at(size_t key) const;
+  size_t at(size_t i) const;
   void push_back(size_t key);
 
   // enabling serialization functionality
@@ -194,4 +195,15 @@ class VariableIndex {
   size_t nEntries() const;
 };
 
+#include <gtsam/inference/Factor.h>
+virtual class Factor {
+  void print(string s = "Factor\n", const gtsam::KeyFormatter& keyFormatter =
+                                        gtsam::DefaultKeyFormatter) const;
+  void printKeys(string s = "") const;
+  bool equals(const gtsam::Factor& other, double tol = 1e-9) const;
+  bool empty() const;
+  size_t size() const;
+  gtsam::KeyVector keys() const;
+};
+
 }  // namespace gtsam

gtsam/inference/inferenceExceptions.cpp

@@ -0,0 +1,60 @@
+/* ----------------------------------------------------------------------------
+
+ * GTSAM Copyright 2010, Georgia Tech Research Corporation,
+ * Atlanta, Georgia 30332-0415
+ * All Rights Reserved
+ * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+
+ * See LICENSE for the license information
+
+ * -------------------------------------------------------------------------- */
+
+/**
+ * @file    inferenceExceptions.cpp
+ * @brief   Exceptions that may be thrown by inference algorithms
+ * @author  Richard Roberts, Varun Agrawal
+ * @date    Apr 25, 2013
+ */
+
+#include <gtsam/inference/inferenceExceptions.h>
+
+#include <sstream>
+
+namespace gtsam {
+
+InconsistentEliminationRequested::InconsistentEliminationRequested(
+    const KeySet& keys, const KeyFormatter& key_formatter)
+    : keys_(keys.begin(), keys.end()), keyFormatter(key_formatter) {}
+
+const char* InconsistentEliminationRequested::what() const noexcept {
+  // Format keys for printing
+  std::stringstream sstr;
+  size_t nrKeysToDisplay = std::min(size_t(4), keys_.size());
+  for (size_t i = 0; i < nrKeysToDisplay; i++) {
+    sstr << keyFormatter(keys_.at(i));
+    if (i < nrKeysToDisplay - 1) {
+      sstr << ", ";
+    }
+  }
+  if (keys_.size() > nrKeysToDisplay) {
+    sstr << ", ... (total " << keys_.size() << " keys)";
+  }
+  sstr << ".";
+  std::string keys = sstr.str();
+
+  std::string msg =
+      "An inference algorithm was called with inconsistent "
+      "arguments.  "
+      "The\n"
+      "factor graph, ordering, or variable index were "
+      "inconsistent with "
+      "each\n"
+      "other, or a full elimination routine was called with "
+      "an ordering "
+      "that\n"
+      "does not include all of the variables.\n";
+  msg += ("Leftover keys after elimination: " + keys);
+  // `new` to allocate memory on heap instead of stack
+  return (new std::string(msg))->c_str();
+}
+}  // namespace gtsam

gtsam/inference/inferenceExceptions.h

@@ -12,30 +12,35 @@
 /**
  * @file    inferenceExceptions.h
  * @brief   Exceptions that may be thrown by inference algorithms
- * @author  Richard Roberts
+ * @author  Richard Roberts, Varun Agrawal
  * @date    Apr 25, 2013
  */
 #pragma once
 
 #include <gtsam/global_includes.h>
+#include <gtsam/inference/Key.h>
+
 #include <exception>
 
 namespace gtsam {
 
-  /** An inference algorithm was called with inconsistent arguments.  The factor graph, ordering, or
+/** An inference algorithm was called with inconsistent arguments.  The factor
-   *  variable index were inconsistent with each other, or a full elimination routine was called
+ * graph, ordering, or variable index were inconsistent with each other, or a
-   *  with an ordering that does not include all of the variables. */
+ * full elimination routine was called with an ordering that does not include
-  class InconsistentEliminationRequested : public std::exception {
+ * all of the variables. */
-  public:
+class InconsistentEliminationRequested : public std::exception {
-    InconsistentEliminationRequested() noexcept {}
+  KeyVector keys_;
-    ~InconsistentEliminationRequested() noexcept override {}
+  const KeyFormatter& keyFormatter = DefaultKeyFormatter;
-    const char* what() const noexcept override {
-      return
-        "An inference algorithm was called with inconsistent arguments.  The\n"
-        "factor graph, ordering, or variable index were inconsistent with each\n"
-        "other, or a full elimination routine was called with an ordering that\n"
-        "does not include all of the variables.";
-    }
-  };
 
-}
+ public:
+  InconsistentEliminationRequested() noexcept {}
+
+  InconsistentEliminationRequested(
+      const KeySet& keys,
+      const KeyFormatter& key_formatter = DefaultKeyFormatter);
+
+  ~InconsistentEliminationRequested() noexcept override {}
+
+  const char* what() const noexcept override;
+};
+}  // namespace gtsam

gtsam/inference/tests/testOrdering.cpp

@@ -196,6 +196,20 @@ TEST(Ordering, csr_format_3) {
   EXPECT(adjExpected == adjAcutal);
 }
 
+/* ************************************************************************* */
+TEST(Ordering, AppendKey) {
+  using symbol_shorthand::X;
+  Ordering actual;
+  actual += X(0);
+
+  Ordering expected1{X(0)};
+  EXPECT(assert_equal(expected1, actual));
+
+  actual += X(1), X(2), X(3);
+  Ordering expected2{X(0), X(1), X(2), X(3)};
+  EXPECT(assert_equal(expected2, actual));
+}
+
 /* ************************************************************************* */
 TEST(Ordering, AppendVector) {
   using symbol_shorthand::X;

gtsam/linear/GaussianConditional.cpp

@@ -99,7 +99,7 @@ namespace gtsam {
 
   /* ************************************************************************ */
   void GaussianConditional::print(const string &s, const KeyFormatter& formatter) const {
-    cout << s << " p(";
+    cout << (s.empty() ? "" : s + " ") << "p(";
     for (const_iterator it = beginFrontals(); it != endFrontals(); ++it) {
       cout << formatter(*it) << (nrFrontals() > 1 ? " " : "");
     }

gtsam/linear/linear.i

@@ -261,8 +261,7 @@ class VectorValues {
 };
 
 #include <gtsam/linear/GaussianFactor.h>
-virtual class GaussianFactor {
+virtual class GaussianFactor : gtsam::Factor {
-  gtsam::KeyVector keys() const;
   void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
                                 gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::GaussianFactor& lf, double tol) const;
@@ -273,8 +272,6 @@ virtual class GaussianFactor {
   Matrix information() const;
   Matrix augmentedJacobian() const;
   pair<Matrix, Vector> jacobian() const;
-  size_t size() const;
-  bool empty() const;
 };
 
 #include <gtsam/linear/JacobianFactor.h>
@@ -301,10 +298,7 @@ virtual class JacobianFactor : gtsam::GaussianFactor {
   //Testable
   void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
                                 gtsam::DefaultKeyFormatter) const;
-  void printKeys(string s) const;
-  gtsam::KeyVector& keys() const;
   bool equals(const gtsam::GaussianFactor& lf, double tol) const;
-  size_t size() const;
   Vector unweighted_error(const gtsam::VectorValues& c) const;
   Vector error_vector(const gtsam::VectorValues& c) const;
   double error(const gtsam::VectorValues& c) const;
@@ -346,10 +340,8 @@ virtual class HessianFactor : gtsam::GaussianFactor {
   HessianFactor(const gtsam::GaussianFactorGraph& factors);
 
   //Testable
-  size_t size() const;
   void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
                                 gtsam::DefaultKeyFormatter) const;
-  void printKeys(string s) const;
   bool equals(const gtsam::GaussianFactor& lf, double tol) const;
   double error(const gtsam::VectorValues& c) const;
 

gtsam/linear/tests/testGaussianFactorGraph.cpp

@@ -21,6 +21,7 @@
 #include <gtsam/linear/GaussianFactorGraph.h>
 #include <gtsam/linear/GaussianConditional.h>
 #include <gtsam/linear/GaussianBayesNet.h>
+#include <gtsam/inference/Symbol.h>
 #include <gtsam/inference/VariableSlots.h>
 #include <gtsam/inference/VariableIndex.h>
 #include <gtsam/base/debug.h>
@@ -70,6 +71,28 @@ TEST(GaussianFactorGraph, initialization) {
   EQUALITY(expectedIJS, actualIJS);
 }
 
+/* ************************************************************************* */
+TEST(GaussianFactorGraph, Append) {
+  // Create empty graph
+  GaussianFactorGraph fg;
+  SharedDiagonal unit2 = noiseModel::Unit::Create(2);
+
+  auto f1 =
+      make_shared<JacobianFactor>(0, 10 * I_2x2, -1.0 * Vector::Ones(2), unit2);
+  auto f2 = make_shared<JacobianFactor>(0, -10 * I_2x2, 1, 10 * I_2x2,
+                                        Vector2(2.0, -1.0), unit2);
+  auto f3 = make_shared<JacobianFactor>(0, -5 * I_2x2, 2, 5 * I_2x2,
+                                        Vector2(0.0, 1.0), unit2);
+
+  fg += f1;
+  fg += f2;
+  EXPECT_LONGS_EQUAL(2, fg.size());
+
+  fg = GaussianFactorGraph();
+  fg += f1, f2, f3;
+  EXPECT_LONGS_EQUAL(3, fg.size());
+}
+
 /* ************************************************************************* */
 TEST(GaussianFactorGraph, sparseJacobian) {
   // Create factor graph:
@@ -435,6 +458,64 @@ TEST(GaussianFactorGraph, ProbPrime) {
   EXPECT_DOUBLES_EQUAL(expected, gfg.probPrime(values), 1e-12);
 }
 
+TEST(GaussianFactorGraph, InconsistentEliminationMessage) {
+  // Create empty graph
+  GaussianFactorGraph fg;
+  SharedDiagonal unit2 = noiseModel::Unit::Create(2);
+
+  using gtsam::symbol_shorthand::X;
+  fg.emplace_shared<JacobianFactor>(0, 10 * I_2x2, -1.0 * Vector::Ones(2),
+                                    unit2);
+  fg.emplace_shared<JacobianFactor>(0, -10 * I_2x2, 1, 10 * I_2x2,
+                                    Vector2(2.0, -1.0), unit2);
+  fg.emplace_shared<JacobianFactor>(1, -5 * I_2x2, 2, 5 * I_2x2,
+                                    Vector2(-1.0, 1.5), unit2);
+  fg.emplace_shared<JacobianFactor>(2, -5 * I_2x2, X(3), 5 * I_2x2,
+                                    Vector2(-1.0, 1.5), unit2);
+
+  Ordering ordering{0, 1};
+
+  try {
+    fg.eliminateSequential(ordering);
+  } catch (const exception& exc) {
+    std::string expected_exception_message = "An inference algorithm was called with inconsistent "
+        "arguments.  "
+        "The\n"
+        "factor graph, ordering, or variable index were "
+        "inconsistent with "
+        "each\n"
+        "other, or a full elimination routine was called with "
+        "an ordering "
+        "that\n"
+        "does not include all of the variables.\n"
+        "Leftover keys after elimination: 2, x3.";
+    EXPECT(expected_exception_message == exc.what());
+  }
+
+  // Test large number of keys
+  fg = GaussianFactorGraph();
+  for (size_t i = 0; i < 1000; i++) {
+    fg.emplace_shared<JacobianFactor>(i, -I_2x2, i + 1, I_2x2,
+                                      Vector2(2.0, -1.0), unit2);
+  }
+
+  try {
+    fg.eliminateSequential(ordering);
+  } catch (const exception& exc) {
+    std::string expected_exception_message = "An inference algorithm was called with inconsistent "
+        "arguments.  "
+        "The\n"
+        "factor graph, ordering, or variable index were "
+        "inconsistent with "
+        "each\n"
+        "other, or a full elimination routine was called with "
+        "an ordering "
+        "that\n"
+        "does not include all of the variables.\n"
+        "Leftover keys after elimination: 2, 3, 4, 5, ... (total 999 keys).";
+    EXPECT(expected_exception_message == exc.what());
+  }
+}
 /* ************************************************************************* */
 int main() {
   TestResult tr;

gtsam/nonlinear/nonlinear.i

@@ -109,13 +109,10 @@ class NonlinearFactorGraph {
 };
 
 #include <gtsam/nonlinear/NonlinearFactor.h>
-virtual class NonlinearFactor {
+virtual class NonlinearFactor : gtsam::Factor {
   // Factor base class
-  size_t size() const;
-  gtsam::KeyVector keys() const;
   void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
                                 gtsam::DefaultKeyFormatter) const;
-  void printKeys(string s) const;
   // NonlinearFactor
   bool equals(const gtsam::NonlinearFactor& other, double tol) const;
   double error(const gtsam::Values& c) const;

gtsam/sfm/ShonanAveraging.cpp

@@ -894,6 +894,9 @@ template <size_t d>
 std::pair<Values, double> ShonanAveraging<d>::run(const Values &initialEstimate,
                                                   size_t pMin,
                                                   size_t pMax) const {
+  if (pMin < d) {
+    throw std::runtime_error("pMin is smaller than the base dimension d");
+  }
   Values Qstar;
   Values initialSOp = LiftTo<Rot>(pMin, initialEstimate);  // lift to pMin!
   for (size_t p = pMin; p <= pMax; p++) {

gtsam/sfm/tests/testShonanAveraging.cpp

@@ -415,6 +415,20 @@ TEST(ShonanAveraging3, PriorWeights) {
   auto result = shonan.run(initial, 3, 3);
   EXPECT_DOUBLES_EQUAL(0.0015, shonan.cost(result.first), 1e-4);
 }
+
+/* ************************************************************************* */
+// Check a small graph created using binary measurements
+TEST(ShonanAveraging3, BinaryMeasurements) {
+  std::vector<BinaryMeasurement<Rot3>> measurements;
+  auto unit3 = noiseModel::Unit::Create(3);
+  measurements.emplace_back(0, 1, Rot3::Yaw(M_PI_2), unit3);
+  measurements.emplace_back(1, 2, Rot3::Yaw(M_PI_2), unit3);
+  ShonanAveraging3 shonan(measurements);
+  Values initial = shonan.initializeRandomly();
+  auto result = shonan.run(initial, 3, 5);
+  EXPECT_DOUBLES_EQUAL(0.0, shonan.cost(result.first), 1e-4);
+}
+
 /* ************************************************************************* */
 int main() {
   TestResult tr;

gtsam/symbolic/SymbolicJunctionTree.h

@@ -65,4 +65,6 @@ namespace gtsam {
     SymbolicJunctionTree(const SymbolicEliminationTree& eliminationTree);
   };
 
+  /// typedef for wrapper:
+  using SymbolicCluster = SymbolicJunctionTree::Cluster;
 }

gtsam/symbolic/symbolic.i

@@ -4,7 +4,7 @@
 namespace gtsam {
 
 #include <gtsam/symbolic/SymbolicFactor.h>
-virtual class SymbolicFactor {
+virtual class SymbolicFactor : gtsam::Factor {
   // Standard Constructors and Named Constructors
   SymbolicFactor(const gtsam::SymbolicFactor& f);
   SymbolicFactor();
@@ -18,12 +18,10 @@ virtual class SymbolicFactor {
   static gtsam::SymbolicFactor FromKeys(const gtsam::KeyVector& js);
 
   // From Factor
-  size_t size() const;
   void print(string s = "SymbolicFactor",
              const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::SymbolicFactor& other, double tol) const;
-  gtsam::KeyVector keys();
 };
 
 #include <gtsam/symbolic/SymbolicFactorGraph.h>
@@ -139,7 +137,60 @@ class SymbolicBayesNet {
       const gtsam::DotWriter& writer = gtsam::DotWriter()) const;
 };
 
+#include <gtsam/symbolic/SymbolicEliminationTree.h>
+
+class SymbolicEliminationTree {
+  SymbolicEliminationTree(const gtsam::SymbolicFactorGraph& factorGraph,
+                          const gtsam::VariableIndex& structure,
+                          const gtsam::Ordering& order);
+
+  SymbolicEliminationTree(const gtsam::SymbolicFactorGraph& factorGraph,
+                          const gtsam::Ordering& order);
+
+  void print(
+      string name = "EliminationTree: ",
+      const gtsam::KeyFormatter& formatter = gtsam::DefaultKeyFormatter) const;
+  bool equals(const gtsam::SymbolicEliminationTree& other,
+              double tol = 1e-9) const;
+};
+
+#include <gtsam/symbolic/SymbolicJunctionTree.h>
+
+class SymbolicCluster {
+  gtsam::Ordering orderedFrontalKeys;
+  gtsam::SymbolicFactorGraph factors;
+  const gtsam::SymbolicCluster& operator[](size_t i) const;
+  size_t nrChildren() const;
+  void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
+                                gtsam::DefaultKeyFormatter) const;
+};
+
+class SymbolicJunctionTree {
+  SymbolicJunctionTree(const gtsam::SymbolicEliminationTree& eliminationTree);
+  void print(
+      string name = "JunctionTree: ",
+      const gtsam::KeyFormatter& formatter = gtsam::DefaultKeyFormatter) const;
+  size_t nrRoots() const;
+  const gtsam::SymbolicCluster& operator[](size_t i) const;
+};
+
 #include <gtsam/symbolic/SymbolicBayesTree.h>
+
+class SymbolicBayesTreeClique {
+  SymbolicBayesTreeClique();
+  SymbolicBayesTreeClique(const gtsam::SymbolicConditional* conditional);
+  bool equals(const gtsam::SymbolicBayesTreeClique& other, double tol) const;
+  void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
+                                gtsam::DefaultKeyFormatter);
+  const gtsam::SymbolicConditional* conditional() const;
+  bool isRoot() const;
+  gtsam::SymbolicBayesTreeClique* parent() const;
+  size_t treeSize() const;
+  size_t numCachedSeparatorMarginals() const;
+  void deleteCachedShortcuts();
+};
+
+
 class SymbolicBayesTree {
   // Constructors
   SymbolicBayesTree();
@@ -151,9 +202,14 @@ class SymbolicBayesTree {
   bool equals(const gtsam::SymbolicBayesTree& other, double tol) const;
 
   // Standard Interface
-  // size_t findParentClique(const gtsam::IndexVector& parents) const;
+  bool empty() const;
-  size_t size();
+  size_t size() const;
-  void saveGraph(string s) const;
+
+  const gtsam::SymbolicBayesTreeClique* operator[](size_t j) const;
+
+  void saveGraph(string s,
+                const gtsam::KeyFormatter& keyFormatter =
+                 gtsam::DefaultKeyFormatter) const;
   void clear();
   void deleteCachedShortcuts();
   size_t numCachedSeparatorMarginals() const;
@@ -161,28 +217,9 @@ class SymbolicBayesTree {
   gtsam::SymbolicConditional* marginalFactor(size_t key) const;
   gtsam::SymbolicFactorGraph* joint(size_t key1, size_t key2) const;
   gtsam::SymbolicBayesNet* jointBayesNet(size_t key1, size_t key2) const;
-};
 
-class SymbolicBayesTreeClique {
+  string dot(const gtsam::KeyFormatter& keyFormatter =
-  SymbolicBayesTreeClique();
+                 gtsam::DefaultKeyFormatter) const;
-  // SymbolicBayesTreeClique(gtsam::sharedConditional* conditional);
-
-  bool equals(const gtsam::SymbolicBayesTreeClique& other, double tol) const;
-  void print(string s = "", const gtsam::KeyFormatter& keyFormatter =
-                                gtsam::DefaultKeyFormatter) const;
-  size_t numCachedSeparatorMarginals() const;
-  // gtsam::sharedConditional* conditional() const;
-  bool isRoot() const;
-  size_t treeSize() const;
-  gtsam::SymbolicBayesTreeClique* parent() const;
-
-  //   // TODO: need wrapped versions graphs, BayesNet
-  //  BayesNet<ConditionalType> shortcut(derived_ptr root, Eliminate function)
-  //  const; FactorGraph<FactorType> marginal(derived_ptr root, Eliminate
-  //  function) const; FactorGraph<FactorType> joint(derived_ptr C2, derived_ptr
-  //  root, Eliminate function) const;
-  //
-  void deleteCachedShortcuts();
 };
 
 }  // namespace gtsam

gtsam_unstable/linear/tests/testQPSolver.cpp

@@ -181,7 +181,7 @@ TEST(QPSolver, iterate) {
   QPSolver::State state(currentSolution, VectorValues(), workingSet, false,
                         100);
 
-  int it = 0;
+  // int it = 0;
   while (!state.converged) {
     state = solver.iterate(state);
     // These checks will fail because the expected solutions obtained from
@@ -190,7 +190,7 @@ TEST(QPSolver, iterate) {
     // do not recompute dual variables after every step!!!
     //    CHECK(assert_equal(expected[it], state.values, 1e-10));
     //    CHECK(assert_equal(expectedDuals[it], state.duals, 1e-10));
-    it++;
+    // it++;
   }
 
   CHECK(assert_equal(expected[3], state.values, 1e-10));

python/gtsam/tests/test_DecisionTreeFactor.py

@@ -26,7 +26,13 @@ class TestDecisionTreeFactor(GtsamTestCase):
         self.B = (5, 2)
         self.factor = DecisionTreeFactor([self.A, self.B], "1 2  3 4  5 6")
 
+    def test_from_floats(self):
+        """Test whether we can construct a factor from floats."""
+        actual = DecisionTreeFactor([self.A, self.B], [1., 2.,  3., 4.,  5., 6.])
+        self.gtsamAssertEquals(actual, self.factor)
+
     def test_enumerate(self):
+        """Test whether we can enumerate the factor."""
         actual = self.factor.enumerate()
         _, values = zip(*actual)
         self.assertEqual(list(values), [1.0, 2.0, 3.0, 4.0, 5.0, 6.0])

python/gtsam/tests/test_DiscreteBayesTree.py

@@ -13,10 +13,15 @@ Author: Frank Dellaert
 
 import unittest
 
-from gtsam import (DiscreteBayesNet, DiscreteBayesTreeClique,
+import numpy as np
-                   DiscreteConditional, DiscreteFactorGraph, Ordering)
+from gtsam.symbol_shorthand import A, X
 from gtsam.utils.test_case import GtsamTestCase
 
+import gtsam
+from gtsam import (DiscreteBayesNet, DiscreteBayesTreeClique,
+                   DiscreteConditional, DiscreteFactorGraph,
+                   DiscreteValues, Ordering)
+
 
 class TestDiscreteBayesNet(GtsamTestCase):
     """Tests for Discrete Bayes Nets."""
@@ -27,7 +32,7 @@ class TestDiscreteBayesNet(GtsamTestCase):
         # Define DiscreteKey pairs.
         keys = [(j, 2) for j in range(15)]
 
-        # Create thin-tree Bayesnet.
+        # Create thin-tree Bayes net.
         bayesNet = DiscreteBayesNet()
 
         bayesNet.add(keys[0], [keys[8], keys[12]], "2/3 1/4 3/2 4/1")
@@ -65,15 +70,91 @@ class TestDiscreteBayesNet(GtsamTestCase):
         #     bayesTree[key].printSignature()
         # bayesTree.saveGraph("test_DiscreteBayesTree.dot")
 
-        self.assertFalse(bayesTree.empty())
-        self.assertEqual(12, bayesTree.size())
-
         # The root is P( 8 12 14), we can retrieve it by key:
         root = bayesTree[8]
         self.assertIsInstance(root, DiscreteBayesTreeClique)
         self.assertTrue(root.isRoot())
         self.assertIsInstance(root.conditional(), DiscreteConditional)
 
+        # Test all methods in DiscreteBayesTree
+        self.gtsamAssertEquals(bayesTree, bayesTree)
+
+        # Check value at 0
+        zero_values = DiscreteValues()
+        for j in range(15):
+            zero_values[j] = 0
+        value_at_zeros = bayesTree.evaluate(zero_values)
+        self.assertAlmostEqual(value_at_zeros, 0.0)
+
+        # Check value at max
+        values_star = factorGraph.optimize()
+        max_value = bayesTree.evaluate(values_star)
+        self.assertAlmostEqual(max_value, 0.002548)
+
+        # Check operator sugar
+        max_value = bayesTree(values_star)
+        self.assertAlmostEqual(max_value, 0.002548)
+
+        self.assertFalse(bayesTree.empty())
+        self.assertEqual(12, bayesTree.size())
+
+    def test_discrete_bayes_tree_lookup(self):
+        """Check that we can have a multi-frontal lookup table."""
+        # Make a small planning-like graph: 3 states, 2 actions
+        graph = DiscreteFactorGraph()
+        x1, x2, x3 = (X(1), 3), (X(2), 3), (X(3), 3)
+        a1, a2 = (A(1), 2), (A(2), 2)
+
+        # Constraint on start and goal
+        graph.add([x1], np.array([1, 0, 0]))
+        graph.add([x3], np.array([0, 0, 1]))
+
+        # Should I stay or should I go?
+        # "Reward" (exp(-cost)) for an action is 10, and rewards multiply:
+        r = 10
+        table = np.array([
+            r, 0, 0, 0, r, 0,  # x1 = 0
+            0, r, 0, 0, 0, r,  # x1 = 1
+            0, 0, r, 0, 0, r   # x1 = 2
+        ])
+        graph.add([x1, a1, x2], table)
+        graph.add([x2, a2, x3], table)
+
+        # Eliminate for MPE (maximum probable explanation).
+        ordering = Ordering(keys=[A(2), X(3), X(1), A(1), X(2)])
+        lookup = graph.eliminateMultifrontal(ordering, gtsam.EliminateForMPE)
+
+        # Check that the lookup table is correct
+        assert lookup.size() == 2
+        lookup_x1_a1_x2 = lookup[X(1)].conditional()
+        assert lookup_x1_a1_x2.nrFrontals() == 3
+        # Check that sum is 1.0 (not 100, as we now normalize to prevent underflow)
+        empty = gtsam.DiscreteValues()
+        self.assertAlmostEqual(lookup_x1_a1_x2.sum(3)(empty), 1.0)
+        # And that only non-zero reward is for x1 a1 x2 == 0 1 1
+        values = DiscreteValues()
+        values[X(1)] = 0
+        values[A(1)] = 1
+        values[X(2)] = 1
+        self.assertAlmostEqual(lookup_x1_a1_x2(values), 1.0)
+
+        lookup_a2_x3 = lookup[X(3)].conditional()
+        # Check that the sum depends on x2 and is non-zero only for x2 in {1, 2}
+        sum_x2 = lookup_a2_x3.sum(2)
+        values = DiscreteValues()
+        values[X(2)] = 0
+        self.assertAlmostEqual(sum_x2(values), 0)
+        values[X(2)] = 1
+        self.assertAlmostEqual(sum_x2(values), 1.0)  # not 10, as we normalize
+        values[X(2)] = 2
+        self.assertAlmostEqual(sum_x2(values), 2.0)  # not 20, as we normalize
+        assert lookup_a2_x3.nrFrontals() == 2
+        # And that the non-zero rewards are for x2 a2 x3 == 1 1 2
+        values = DiscreteValues()
+        values[X(2)] = 1
+        values[A(2)] = 1
+        values[X(3)] = 2
+        self.assertAlmostEqual(lookup_a2_x3(values), 1.0)  # not 10...
 
 if __name__ == "__main__":
     unittest.main()

python/gtsam/tests/test_ShonanAveraging.py

@@ -10,14 +10,16 @@ Author: Frank Dellaert
 """
 # pylint: disable=invalid-name, no-name-in-module, no-member
 
+import math
 import unittest
 
 import numpy as np
 from gtsam.utils.test_case import GtsamTestCase
 
 import gtsam
-from gtsam import (BetweenFactorPose2, LevenbergMarquardtParams, Pose2, Rot2,
+from gtsam import (BetweenFactorPose2, BetweenFactorPose3,
-                   ShonanAveraging2, ShonanAveraging3,
+                   BinaryMeasurementRot3, LevenbergMarquardtParams, Pose2,
+                   Pose3, Rot2, Rot3, ShonanAveraging2, ShonanAveraging3,
                    ShonanAveragingParameters2, ShonanAveragingParameters3)
 
 DEFAULT_PARAMS = ShonanAveragingParameters3(
@@ -197,6 +199,19 @@ class TestShonanAveraging(GtsamTestCase):
         expected_thetas_deg = np.array([0.0, 90.0, 0.0])
         np.testing.assert_allclose(thetas_deg, expected_thetas_deg, atol=0.1)
 
+    def test_measurements3(self):
+        """Create from Measurements."""
+        measurements = []
+        unit3 = gtsam.noiseModel.Unit.Create(3)
+        m01 = BinaryMeasurementRot3(0, 1, Rot3.Yaw(math.radians(90)), unit3)
+        m12 = BinaryMeasurementRot3(1, 2, Rot3.Yaw(math.radians(90)), unit3)
+        measurements.append(m01)
+        measurements.append(m12)
+        obj = ShonanAveraging3(measurements)
+        self.assertIsInstance(obj, ShonanAveraging3)
+        initial = obj.initializeRandomly()
+        _, cost = obj.run(initial, min_p=3, max_p=5)
+        self.assertAlmostEqual(cost, 0)
 
 if __name__ == "__main__":
     unittest.main()

python/gtsam/tests/test_VisualISAMExample.py

@@ -84,7 +84,7 @@ class TestVisualISAMExample(GtsamTestCase):
 
             values.insert(key, v)
 
-        self.assertAlmostEqual(isam.error(values), 34212421.14731998)
+        self.assertAlmostEqual(isam.error(values), 34212421.14732)
 
     def test_isam2_update(self):
         """