gtsam/gtsam/inference/inference.h

115 lines
4.6 KiB
C++

/* ----------------------------------------------------------------------------
* 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 inference.h
* @brief Contains *generic* inference algorithms that convert between templated
* graphical models, i.e., factor graphs, Bayes nets, and Bayes trees
* @author Frank Dellaert
* @author Richard Roberts
*/
#pragma once
#include <gtsam/inference/VariableIndex.h>
#include <gtsam/inference/Permutation.h>
#include <boost/foreach.hpp>
#include <boost/optional.hpp>
#include <deque>
namespace gtsam {
namespace inference {
/**
* Compute a permutation (variable ordering) using colamd
*/
Permutation::shared_ptr PermutationCOLAMD(
const VariableIndex& variableIndex);
/**
* Compute a permutation (variable ordering) using constrained colamd to move
* a set of variables to the end of the ordering
* @param variableIndex is the variable index lookup from a graph
* @param constrainlast is a vector of keys that should be constrained
* @tparam constrainLast is a std::vector (or similar structure)
* @param forceOrder if true, will not allow re-ordering of constrained variables
*/
template<typename CONSTRAINED>
Permutation::shared_ptr PermutationCOLAMD(
const VariableIndex& variableIndex, const CONSTRAINED& constrainLast, bool forceOrder=false);
/**
* Compute a permutation of variable ordering using constrained colamd to
* move variables to the end in groups (0 = unconstrained, higher numbers at
* the end).
* @param variableIndex is the variable index lookup from a graph
* @param constraintMap is a map from variable index -> group number for constrained variables
* @tparam CONSTRAINED_MAP is an associative structure (like std::map), from size_t->int
*/
template<typename CONSTRAINED_MAP>
Permutation::shared_ptr PermutationCOLAMDGrouped(
const VariableIndex& variableIndex, const CONSTRAINED_MAP& constraints);
/**
* Compute a CCOLAMD permutation using the constraint groups in cmember.
* The format for cmember is a part of ccolamd.
*
* @param variableIndex is the variable structure from a graph
* @param cmember is the constraint group list for each variable, where
* 0 is the default, unconstrained group, and higher numbers move further to
* the back of the list
*
* AGC: does cmember change?
*/
Permutation::shared_ptr PermutationCOLAMD_(
const VariableIndex& variableIndex, std::vector<int>& cmember);
/** Factor the factor graph into a conditional and a remaining factor graph.
* Given the factor graph \f$ f(X) \f$, and \c variables to factorize out
* \f$ V \f$, this function factorizes into \f$ f(X) = f(V;Y)f(Y) \f$, where
* \f$ Y := X\V \f$ are the remaining variables. If \f$ f(X) = p(X) \f$ is
* a probability density or likelihood, the factorization produces a
* conditional probability density and a marginal \f$ p(X) = p(V|Y)p(Y) \f$.
*
* For efficiency, this function treats the variables to eliminate
* \c variables as fully-connected, so produces a dense (fully-connected)
* conditional on all of the variables in \c variables, instead of a sparse
* BayesNet. If the variables are not fully-connected, it is more efficient
* to sequentially factorize multiple times.
*/
template<class Graph>
std::pair<typename Graph::sharedConditional, Graph> eliminate(
const Graph& factorGraph,
const std::vector<typename Graph::KeyType>& variables,
const typename Graph::Eliminate& eliminateFcn,
boost::optional<const VariableIndex&> variableIndex = boost::none);
/** Eliminate a single variable, by calling
* eliminate(const Graph&, const std::vector<typename Graph::KeyType>&, const typename Graph::Eliminate&, boost::optional<const VariableIndex&>)
*/
template<class Graph>
std::pair<typename Graph::sharedConditional, Graph> eliminateOne(
const Graph& factorGraph, typename Graph::KeyType variable,
const typename Graph::Eliminate& eliminateFcn,
boost::optional<const VariableIndex&> variableIndex = boost::none) {
std::vector<size_t> variables(1, variable);
return eliminate(factorGraph, variables, eliminateFcn, variableIndex);
}
} // \namespace inference
} // \namespace gtsam
#include <gtsam/inference/inference-inl.h>