Added findExampleDataFile to C++ gtsam (already existed in Matlab interface)

gtsam/CMakeLists.txt

@@ -114,6 +114,12 @@ if (GTSAM_BUILD_SHARED_LIBRARY)
     endif()
 endif(GTSAM_BUILD_SHARED_LIBRARY)
 
+# Set dataset paths
+set_property(SOURCE "${CMAKE_CURRENT_SOURCE_DIR}/slam/dataset.cpp"
+    APPEND PROPERTY COMPILE_DEFINITIONS
+	"SOURCE_TREE_DATASET_DIR=\"${CMAKE_SOURCE_DIR}/examples/Data\""
+	"INSTALLED_DATASET_DIR=\"${GTSAM_TOOLBOX_INSTALL_PATH}/gtsam_examples/Data\"")
+
 # Create the matlab toolbox for the gtsam library
 if (GTSAM_INSTALL_MATLAB_TOOLBOX)
     # Set up codegen

gtsam/slam/dataset.cpp

@@ -20,6 +20,8 @@
 #include <sstream>
 #include <cstdlib>
 
+#include <boost/filesystem.hpp>
+
 #include <gtsam/geometry/Pose2.h>
 #include <gtsam/linear/Sampler.h>
 #include <gtsam/slam/dataset.h>
@@ -27,11 +29,41 @@
 #include <gtsam/slam/BearingRangeFactor.h>
 
 using namespace std;
+namespace fs = boost::filesystem;
 
 #define LINESIZE 81920
 
 namespace gtsam {
 
+/* ************************************************************************* */
+string findExampleDataFile(const string& name) {
+	// Search source tree and installed location
+	vector<string> rootsToSearch;
+	rootsToSearch.push_back(SOURCE_TREE_DATASET_DIR); // Defined by CMake, see gtsam/gtsam/CMakeLists.txt
+	rootsToSearch.push_back(INSTALLED_DATASET_DIR);   // Defined by CMake, see gtsam/gtsam/CMakeLists.txt
+
+	// Search for filename as given, and with .graph and .txt extensions
+	vector<string> namesToSearch;
+	namesToSearch.push_back(name);
+	namesToSearch.push_back(name + ".graph");
+	namesToSearch.push_back(name + ".txt");
+
+	// Find first name that exists
+	BOOST_FOREACH(const fs::path& root, rootsToSearch) {
+		BOOST_FOREACH(const fs::path& name, namesToSearch) {
+			if(fs::is_regular_file(root / name))
+				return (root / name).string();
+		}
+	}
+
+	// If we did not return already, then we did not find the file
+	throw std::invalid_argument(
+		"gtsam::findExampleDataFile could not find a matching file in\n"
+		SOURCE_TREE_DATASET_DIR " or\n"
+		INSTALLED_DATASET_DIR " named\n" +
+		name + ", " + name + ".graph, or " + name + ".txt");
+}
+
 /* ************************************************************************* */
 pair<NonlinearFactorGraph::shared_ptr, Values::shared_ptr> load2D(
 		pair<string, boost::optional<noiseModel::Diagonal::shared_ptr> > dataset,

gtsam/slam/dataset.h

@@ -25,6 +25,19 @@
 
 namespace gtsam {
 
+	/**
+	 * Find the full path to an example dataset distributed with gtsam.  The name
+	 * may be specified with or without a file extension - if no extension is
+	 * give, this function first looks for the .graph extension, then .txt.  We
+	 * first check the gtsam source tree for the file, followed by the installed
+	 * example dataset location.  Both the source tree and installed locations
+	 * are obtained from CMake during compilation.
+	 * @return The full path and filename to the requested dataset.
+	 * @throw std::invalid_argument if no matching file could be found using the
+	 * search process described above.
+	 */
+	std::string findExampleDataFile(const std::string& name);
+
 	/**
 	 * Load TORO 2D Graph
 	 * @param dataset/model pair as constructed by [dataset]

gtsam/slam/tests/testDataset.cpp

@@ -0,0 +1,34 @@
+/* ----------------------------------------------------------------------------
+
+ * 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    testDataset.cpp
+ * @brief   Unit test for dataset.cpp
+ * @author  Richard Roberts
+ */
+
+#include <CppUnitLite/TestHarness.h>
+
+#include <boost/algorithm/string.hpp>
+
+#include <gtsam/base/TestableAssertions.h>
+#include <gtsam/slam/dataset.h>
+
+using namespace std;
+using namespace gtsam;
+
+TEST(dataSet, findExampleDataFile) {
+	const string expected_end = "gtsam/examples/Data/example.graph";
+	const string actual = findExampleDataFile("example");
+	string actual_end = actual.substr(actual.size() - expected_end.size(), expected_end.size());
+	boost::replace_all(actual_end, "\\", "/"); // Convert directory separators to forward-slash
+	EXPECT(assert_equal(expected_end, actual_end));
+}