diff --git a/dollar/Engine.cpp b/dollar/Engine.cpp
index 714578e..b6a7516 100644
--- a/dollar/Engine.cpp
+++ b/dollar/Engine.cpp
@@ -55,6 +55,7 @@ static float pathDistance(const std::vector<vec2>& _path1, const std::vector<vec
 
 dollar::Engine::Engine():
   m_PPlusDistance(0.10f),
+  m_PPlusExcludeDistance(0.2*0.2),
   m_scaleKeepRatio(false) {
 	m_numPointsInGesture = 128;
 	DOLLAR_ASSERT(m_numPointsInGesture>16, "NB element in a path must be > 16 ...");
@@ -78,19 +79,29 @@ size_t dollar::Engine::getNumberPointInGesture() {
 }
 
 void dollar::Engine::setPPlusDistance(float _value) {
-	if (_value == m_PPlusDistance) {
+	if (_value*_value == m_PPlusDistance*) {
 		return;
 	}
-	m_PPlusDistance = _value;
+	m_PPlusDistance = _value*_value;
 	for (auto &it: m_gestures) {
 		it.configure(m_numPointsInGesture/RATIO_START_VECTOR, m_numPointsInGesture, m_paramterIgnoreRotation, m_PPlusDistance, m_scaleKeepRatio);
 	}
 }
 
 float dollar::Engine::getPPlusDistance() {
-	return m_PPlusDistance;
+	return std::sqrt(m_PPlusDistance);
 }
 
+void dollar::Engine::setPPlusExcludeDistance(float _value) {
+	if (_value == m_PPlusExcludeDistance) {
+		return;
+	}
+	m_PPlusExcludeDistance = _value;
+}
+
+float dollar::Engine::getPPlusExcludeDistance() {
+	return m_PPlusExcludeDistance;
+}
 void dollar::Engine::setScaleKeepRatio(bool _value) {
 	if (_value == m_scaleKeepRatio) {
 		return;
@@ -207,7 +218,7 @@ static float calculatePPlusDistance(const std::vector<vec2>& _points,
 		}
 		if (kkkBest != -1) {
 			// reject the distance ... if too big ...
-			if (bestDistance <= 0.2*0.2) {
+			if (bestDistance <= m_PPlusExcludeDistance) {
 				int32_t previous = usedId[kkkBest];
 				usedId[kkkBest] = iii;
 				distance[iii] = bestDistance;
@@ -560,7 +571,7 @@ dollar::Results dollar::Engine::recognizePPlus(const std::vector<std::vector<vec
 			continue;
 		}
 		if (gesture.getEnginePoints().size() == 0) {
-			DOLLAR_ERROR("Reference path with no Value");
+			//DOLLAR_ERROR("Reference path with no Value");
 			continue;
 		}
 		float distance = MAX_FLOAT;
diff --git a/dollar/Engine.h b/dollar/Engine.h
index 149b830..f481410 100644
--- a/dollar/Engine.h
+++ b/dollar/Engine.h
@@ -20,6 +20,11 @@ namespace dollar {
 		public:
 			void setPPlusDistance(float _value);
 			float getPPlusDistance();
+		protected:
+			float m_PPlusExcludeDistance;
+		public:
+			void setPPlusExcludeDistance(float _value);
+			float setPPlusExcludeDistance();
 		protected:
 			bool m_scaleKeepRatio; // when rescale the path, keep the aspect ration for processing
 		public:
diff --git a/dollar/tools.cpp b/dollar/tools.cpp
index ad92c20..8128d78 100644
--- a/dollar/tools.cpp
+++ b/dollar/tools.cpp
@@ -115,6 +115,9 @@ std::vector<vec2> dollar::translateBariCenterToZero(std::vector<vec2> _points) {
 
 static std::vector<vec2> discretize(std::vector<vec2> _points, float _interval) {
 	std::vector<vec2> out;
+	if (_points.size() == 0) {
+		return out;
+	}
 	// same first point ==> no change
 	out.push_back(_points.front());
 	float distance = 0.0f;
@@ -137,6 +140,9 @@ static std::vector<vec2> discretize(std::vector<vec2> _points, float _interval)
 
 std::vector<vec2> dollar::resample(std::vector<vec2> _points, int32_t _nbPoints) {
 	std::vector<vec2> out;
+	if (_points.size() == 0) {
+		return out;
+	}
 	// calculate the interval between every points ...
 	float interval = pathLength(_points) / (_nbPoints - 1);
 	out = discretize(_points, interval);
@@ -191,6 +197,9 @@ std::vector<vec2> dollar::combineStrokes(const std::vector<std::vector<vec2>>& _
 
 vec2 dollar::getStartVector(const std::vector<vec2>& _points, float _index) {
 	DOLLAR_ASSERT(_index > 0, "index must be != of 0");
+	if (_points.size() <= _index) {
+		return vec2(1.0, 0.0);
+	}
 	vec2 vect = _points[_index] - _points[0];
 	float len = vect.length();
 	return vect / len;
diff --git a/tool/generate-form/main.cpp b/tool/generate-form/main.cpp
index 14fa097..b2fe26b 100644
--- a/tool/generate-form/main.cpp
+++ b/tool/generate-form/main.cpp
@@ -24,10 +24,20 @@ void usage(const std::string& _progName) {
 
 bool testCorpus(const std::string& _srcCorpus);
 
+static bool keepAspectRatio = false;
+static float distanceReference; // distance of the gesture reference [0.02, 0.3]
+static float distanceCheck; // distance of the test points           [0.02, 0.3]
+static float distanceExclude; // distance of the exclusion point     [0.1, 1.0]
+
+setScaleKeepRatio(keepAspectRatio);
+setPPlusDistance(distanceReference); // to generate reference gesture
+setPPlusDistance(distanceCheck); // to generate test gesture
+setPPlusExcludeDistance(distanceExclude);
 int main(int _argc, const char *_argv[]) {
 	// init etk log system and file interface:
 	etk::init(_argc, _argv);
 	std::string srcCorpus;
+	
 	for (int32_t iii=1; iii<_argc; ++iii) {
 		std::string arg = _argv[iii];
 		if (    arg == "-h"
@@ -35,8 +45,27 @@ int main(int _argc, const char *_argv[]) {
 			usage(_argv[0]);
 			return 0;
 		}
-		if(    arg[0] == '-'
-		    && arg[1] == '-') {
+		if (arg == "--keep_ratio") {
+			keepAspectRatio = true;
+			continue;
+		}
+		if (etk::start_with(arg,"--dist-ref=") == true) {
+			std::string val(&arg[11]);
+			distanceReference = etk::string_to_float(val);
+			continue;
+		}
+		if (etk::start_with(arg,"--dist-check=") == true) {
+			std::string val(&arg[13]);
+			distanceCheck = etk::string_to_float(val);
+			continue;
+		}
+		if (etk::start_with(arg,"--dist-excl=") == true) {
+			std::string val(&arg[12]);
+			distanceExclude = etk::string_to_float(val);
+			continue;
+		}
+		if (    arg[0] == '-'
+		     && arg[1] == '-') {
 			// subLibrary usage ...
 			continue;
 		}
@@ -118,13 +147,14 @@ bool testCorpus(const std::string& _srcCorpus) {
 		}
 	}
 //listOfElementInCorpus.clear();
-//listOfElementInCorpus.push_back("z");
+//listOfElementInCorpus.push_back("slash");
 // Value to stop grouping in the same element ...
 float groupSize = 1.0;
 groupSize = 1.0;
 bool keepAspectRatio = false;
 
 	TEST_PRINT(" will done for: " << listOfElementInCorpus);
+	int32_t nbElementGenerated = 0;
 	for (auto &itTypeOfCorpus : listOfElementInCorpus) {
 		TEST_PRINT("---------------------------------------------------------------------------");
 		TEST_PRINT("-- Generate FOR: '" << itTypeOfCorpus << "'");
@@ -134,7 +164,7 @@ bool keepAspectRatio = false;
 			if (etk::end_with(it, ".json") == true) {
 				std::vector<std::string> path = etk::split(it, '/');
 				std::string filename = path[path.size()-1];
-				if (etk::start_with(filename, itTypeOfCorpus) == true) {
+				if (etk::start_with(filename, itTypeOfCorpus + "_") == true) {
 					fileFiltered.push_back(it);
 				}
 			}
@@ -321,8 +351,12 @@ bool keepAspectRatio = false;
 			
 			// Increment subId...
 			subId++;
+			nbElementGenerated++;
 		}
 	}
+	TEST_PRINT("===========================================================================");
+	TEST_PRINT("== Gererate Done: " << nbElementGenerated);
+	TEST_PRINT("===========================================================================");
 	return 0;
 }