better curvilinear coordinate computation

Fltk/statisticsWindow.cpp

@@ -35,19 +35,31 @@ static void statistics_histogram_cb(Fl_Widget *w, void *data)
   std::vector<double> x, y;
 
   if(name == "Gamma2D"){
-    for(int i = 0; i < 100; i++) y.push_back(FlGui::instance()->stats->quality[0][i]);
+    for(int i = 0; i < 100; i++){
+      x.push_back((double)i / 99);
+      y.push_back(FlGui::instance()->stats->quality[0][i]);
+    }
     new PView("Gamma", "# Elements", x, y);
   }
   else if(name == "Eta2D"){
-    for(int i = 0; i < 100; i++) y.push_back(FlGui::instance()->stats->quality[1][i]);
+    for(int i = 0; i < 100; i++){
+      x.push_back((double)i / 99);
+      y.push_back(FlGui::instance()->stats->quality[1][i]);
+    }
     new PView("Eta", "# Elements", x, y);
   }
   else if(name == "Rho2D"){
-    for(int i = 0; i < 100; i++) y.push_back(FlGui::instance()->stats->quality[2][i]);
+    for(int i = 0; i < 100; i++){
+      x.push_back((double)i / 99);
+      y.push_back(FlGui::instance()->stats->quality[2][i]);
+    }
     new PView("Rho", "# Elements", x, y);
   }
   else if(name == "Disto2D"){
-    for(int i = 0; i < 100; i++) y.push_back(FlGui::instance()->stats->quality[3][i]);
+    for(int i = 0; i < 100; i++){
+      x.push_back((double)i / 99);
+      y.push_back(FlGui::instance()->stats->quality[3][i]);
+    }
     new PView("Disto", "# Elements", x, y);
   }
   else{

Graphics/drawGraph2d.cpp

@@ -117,13 +117,15 @@ static bool getGraphData(PView *p, std::vector<double> &x, double &xmin,
             y[0].push_back(vy);
           }
           else if(opt->type == PViewOptions::Plot2DSpace){
-            // store offset to origin + distance to first point
+            // compute curvilinear coordinate
             if(x.empty()){
               p0 = SPoint3(xyz[0], xyz[1], xyz[2]);
               x.push_back(ComputeScalarRep(3, xyz));
             }
             else{
-              x.push_back(x[0] + p0.distance(SPoint3(xyz[0], xyz[1], xyz[2])));
+              SPoint3 p1(xyz[0], xyz[1], xyz[2]);
+              x.push_back(x.back() + p0.distance(p1));
+              p0 = p1;
             }
             y[0].push_back(vy);
           }