Look for NumPy C-API if building the python module

cmake/FindNumPy.cmake

@@ -0,0 +1,102 @@
+# - Find the NumPy libraries
+# This module finds if NumPy is installed, and sets the following variables
+# indicating where it is.
+#
+# TODO: Update to provide the libraries and paths for linking npymath lib.
+#
+#  NUMPY_FOUND               - was NumPy found
+#  NUMPY_VERSION             - the version of NumPy found as a string
+#  NUMPY_VERSION_MAJOR       - the major version number of NumPy
+#  NUMPY_VERSION_MINOR       - the minor version number of NumPy
+#  NUMPY_VERSION_PATCH       - the patch version number of NumPy
+#  NUMPY_VERSION_DECIMAL     - e.g. version 1.6.1 is 10601
+#  NUMPY_INCLUDE_DIRS        - path to the NumPy include files
+
+#============================================================================
+# Copyright 2012 Continuum Analytics, Inc.
+#
+# MIT License
+#
+# 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.
+#
+#============================================================================
+
+# Finding NumPy involves calling the Python interpreter
+if(NumPy_FIND_REQUIRED)
+    find_package(PythonInterp REQUIRED)
+else()
+    find_package(PythonInterp)
+endif()
+
+if(NOT PYTHONINTERP_FOUND)
+    set(NUMPY_FOUND FALSE)
+    return()
+endif()
+
+execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c"
+    "import numpy as n; print(n.__version__); print(n.get_include());"
+    RESULT_VARIABLE _NUMPY_SEARCH_SUCCESS
+    OUTPUT_VARIABLE _NUMPY_VALUES_OUTPUT
+    ERROR_VARIABLE _NUMPY_ERROR_VALUE
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+if(NOT _NUMPY_SEARCH_SUCCESS MATCHES 0)
+    if(NumPy_FIND_REQUIRED)
+        message(FATAL_ERROR
+            "NumPy import failure:\n${_NUMPY_ERROR_VALUE}")
+    endif()
+    set(NUMPY_FOUND FALSE)
+    return()
+endif()
+
+# Convert the process output into a list
+string(REGEX REPLACE ";" "\\\\;" _NUMPY_VALUES ${_NUMPY_VALUES_OUTPUT})
+string(REGEX REPLACE "\n" ";" _NUMPY_VALUES ${_NUMPY_VALUES})
+# Just in case there is unexpected output from the Python command.
+list(GET _NUMPY_VALUES -2 NUMPY_VERSION)
+list(GET _NUMPY_VALUES -1 NUMPY_INCLUDE_DIRS)
+
+string(REGEX MATCH "^[0-9]+\\.[0-9]+\\.[0-9]+" _VER_CHECK "${NUMPY_VERSION}")
+if("${_VER_CHECK}" STREQUAL "")
+    # The output from Python was unexpected. Raise an error always
+    # here, because we found NumPy, but it appears to be corrupted somehow.
+    message(FATAL_ERROR
+        "Requested version and include path from NumPy, got instead:\n${_NUMPY_VALUES_OUTPUT}\n")
+    return()
+endif()
+
+# Make sure all directory separators are '/'
+string(REGEX REPLACE "\\\\" "/" NUMPY_INCLUDE_DIRS ${NUMPY_INCLUDE_DIRS})
+
+# Get the major and minor version numbers
+string(REGEX REPLACE "\\." ";" _NUMPY_VERSION_LIST ${NUMPY_VERSION})
+list(GET _NUMPY_VERSION_LIST 0 NUMPY_VERSION_MAJOR)
+list(GET _NUMPY_VERSION_LIST 1 NUMPY_VERSION_MINOR)
+list(GET _NUMPY_VERSION_LIST 2 NUMPY_VERSION_PATCH)
+string(REGEX MATCH "[0-9]*" NUMPY_VERSION_PATCH ${NUMPY_VERSION_PATCH})
+math(EXPR NUMPY_VERSION_DECIMAL
+    "(${NUMPY_VERSION_MAJOR} * 10000) + (${NUMPY_VERSION_MINOR} * 100) + ${NUMPY_VERSION_PATCH}")
+
+find_package_message(NUMPY
+    "Found NumPy: version \"${NUMPY_VERSION}\" ${NUMPY_INCLUDE_DIRS}"
+    "${NUMPY_INCLUDE_DIRS}${NUMPY_VERSION}")
+
+set(NUMPY_FOUND TRUE)
+

python/CMakeLists.txt

@@ -28,14 +28,16 @@ else()
 	set(UPPER_BOOST_PYTHON_VERSION_STRING "")
 endif()
 
-# Be sure that python version can be found by FindPythonLibs.cmake
+# Find NumPy C-API
+find_package(NumPy)
+
+# Find Python
+# First, be sure that python version can be found by FindPythonLibs.cmake
 # See: http://stackoverflow.com/a/15660652/2220173
 set(Python_ADDITIONAL_VERSIONS ${GTSAM_PYTHON_VERSION})
-
+# Then look for the the lib. If no version is specified when looking for PythonLibs it searches the default version.
-# Find Python 
+# See: https://cmake.org/cmake/help/v3.1/module/FindPythonInterp.html
 if(GTSAM_PYTHON_VERSION STREQUAL "Default")
-	# If no version is specified when looking for PythonLibs it searches the default version.
-	# See: https://cmake.org/cmake/help/v3.1/module/FindPythonInterp.html
 	find_package(PythonLibs)
 else()
 	find_package(PythonLibs ${GTSAM_PYTHON_VERSION})
@@ -45,7 +47,7 @@ endif()
 find_package(Boost COMPONENTS python${BOOST_PYTHON_VERSION_STRING})
 
 # Add handwritten directory if we found python and boost python
-if(Boost_PYTHON${UPPER_BOOST_PYTHON_VERSION_STRING}_FOUND AND PYTHONLIBS_FOUND)
+if(Boost_PYTHON${UPPER_BOOST_PYTHON_VERSION_STRING}_FOUND AND PYTHONLIBS_FOUND AND NUMPY_FOUND)
 	include_directories(${PYTHON_INCLUDE_DIRS})
 	include_directories(${Boost_INCLUDE_DIRS})
 	include_directories(${CMAKE_SOURCE_DIR}/gtsam/3rdparty/numpy_eigen/include/)
@@ -70,4 +72,8 @@ if(NOT Boost_PYTHON${UPPER_BOOST_PYTHON_VERSION_STRING}_FOUND)
 	else()
 		message(WARNING "Boost Python for python ${GTSAM_PYTHON_VERSION} was not found -- Python module cannot be built. Option GTSAM_BUILD_PYTHON disabled.")
 	endif()
+endif()
+
+if(NOT NUMPY_FOUND)
+	message(WARNING "NumPy C-API was not found -- Python module cannot be built. Option GTSAM_BUILD_PYTHON disabled.")
 endif()