timing VectorConfig to speed up iterative

cpp/Makefile.am

@@ -238,7 +238,7 @@ testVSLAMConfig_LDADD = libgtsam.la
 headers += $(sources:.cpp=.h)
 
 # Timing tests
-noinst_PROGRAMS = timeGaussianFactor timeGaussianFactorGraph timeRot3 timeMatrix timeSymbolMaps
+noinst_PROGRAMS = timeGaussianFactor timeGaussianFactorGraph timeRot3 timeMatrix timeSymbolMaps timeVectorConfig
 timeRot3_SOURCES = timeRot3.cpp
 timeRot3_LDADD   = libgtsam.la
 timeGaussianFactor_SOURCES = timeGaussianFactor.cpp
@@ -249,6 +249,8 @@ timeMatrix_SOURCES 			  = timeMatrix.cpp
 timeMatrix_LDADD 			   = libgtsam.la
 timeSymbolMaps_SOURCES   = timeSymbolMaps.cpp
 timeSymbolMaps_LDADD     = libgtsam.la
+timeVectorConfig_SOURCES = timeVectorConfig.cpp 
+timeVectorConfig_LDADD 	 = libgtsam.la
 
 # create both dynamic and static libraries
 AM_CXXFLAGS = -I$(boost) -fPIC

cpp/timeVectorConfig.cpp

@@ -0,0 +1,57 @@
+/*
+ * @file timeVectorConfig.cpp
+ * @brief Performs timing and profiling for VectorConfig operations
+ * @author Frank Dellaert
+ */
+
+#include <iostream>
+#include <boost/timer.hpp>
+#include "VectorConfig.h"
+
+using namespace std;
+using namespace gtsam;
+
+/*
+ * Results:
+ * Frank's machine:
+ */
+double timeAssignment(size_t n, size_t m, size_t r) {
+	// assign a large VectorConfig
+	// n =  number of times to loop
+	// m =  number of vectors
+	// r =  rows per vector
+
+	// Create 2 VectorConfigs
+	VectorConfig a, b;
+	for (int i = 0; i < m; ++i) {
+		Vector v = zero(r);
+		Symbol key('x', i);
+		a.add(key, v);
+		b.add(key, v);
+	}
+
+	// start timing
+	double elapsed;
+	{
+		boost::timer t;
+
+		for (int j = 0; j < n; ++j)
+			a = b;
+
+		elapsed = t.elapsed();
+	}
+
+	return elapsed;
+}
+
+int main(int argc, char ** argv) {
+
+	// Time assignment operator
+	cout << "Starting operator=() Timing" << endl;
+	size_t n = 1000, m = 10000, r = 3;
+	double time = timeAssignment(n, m, r);
+	cout << "Average Elapsed time for assigning " << m << "*" << r
+			<< " VectorConfigs: " << 10e3 * time / n << "ms." << endl;
+
+	return 0;
+}