Fixed default nearest neighbor approach for the dictionary when the parameter is not set.

rtabmap_gui parameters panel can be opened without rtabmap parameters set on ROS (only GUI parameters can be changed).
Rtabmap: added getStatistics() method for convenience
Rtabmap/Memory: added deleteLastLocation() method to remove the last location in the STM.
 

git-svn-id: http://rtabmap.googlecode.com/svn/trunk/rtabmap@779 f169173b-cf89-36c8-b27e-44dbe73f0c83

corelib/src/VWDictionary.cpp

@@ -50,6 +50,7 @@ VWDictionary::VWDictionary(const ParametersMap & parameters) :
 	_lastWordId(0),
 	_nn(0)
 {
+	this->setNNStrategy((NNStrategy)Parameters::defaultKpNNStrategy(), parameters);
 	this->parseParameters(parameters);
 }
 
@@ -103,7 +104,9 @@ void VWDictionary::parseParameters(const ParametersMap & parameters)
 	{
 		nnStrategy = (NNStrategy)std::atoi((*iter).second.c_str());
 	}
+
 	NNStrategy currentNNStrategy = this->nnStrategy();
+
 	if(!_nn || ( nnStrategy!=kNNUndef && (nnStrategy != currentNNStrategy) ) )
 	{
 		this->setNNStrategy(nnStrategy, parameters);