New example + update examples + documentation

2017-03-01 15:35:01 +01:00
parent 7e181c9c7e
commit 8f4974df7b
6 changed files with 127 additions and 2 deletions
@@ -0,0 +1,99 @@
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <string>
+
+#include <CGAL/Simple_cartesian.h>
+#include <CGAL/Classifier.h>
+#include <CGAL/Classification/Point_set_neighborhood.h>
+#include <CGAL/Classification/Planimetric_grid.h>
+#include <CGAL/Classification/Feature_base.h>
+#include <CGAL/Classification/Feature/Eigen.h>
+
+#include <CGAL/IO/read_ply_points.h>
+
+typedef CGAL::Simple_cartesian<double> Kernel;
+typedef Kernel::Point_3 Point;
+typedef Kernel::Iso_cuboid_3 Iso_cuboid_3;
+typedef std::vector<Point> Point_range;
+typedef CGAL::Identity_property_map<Point> Pmap;
+
+typedef CGAL::Classifier<Point_range, Pmap> Classifier;
+
+typedef CGAL::Classification::Point_set_neighborhood<Kernel, Point_range, Pmap>       Neighborhood;
+typedef CGAL::Classification::Local_eigen_analysis<Kernel, Point_range, Pmap>         Local_eigen_analysis;
+
+typedef CGAL::Classification::Label_handle                                            Label_handle;
+typedef CGAL::Classification::Feature_handle                                          Feature_handle;
+
+typedef CGAL::Classification::Feature::Sphericity<Kernel, Point_range, Pmap>          Sphericity;
+
+
+// User-defined feature that identifies a specific area of the 3D
+// space. This feature takes value 1 for points that lie inside the
+// area and 0 for the others.
+class My_feature : public CGAL::Classification::Feature_base
+{
+  const Point_range& range;
+  double xmin, xmax, ymin, ymax;
+public:
+  My_feature (const Point_range& range, // constructor should start with item range
+              double xmin, double xmax, double ymin, double ymax)
+    : range (range), xmin(xmin), xmax(xmax), ymin(ymin), ymax(ymax)
+  { }
+
+  double value (std::size_t pt_index)
+  {
+    if (xmin < range[pt_index].x() && range[pt_index].x() < xmax &&
+        ymin < range[pt_index].y() && range[pt_index].y() < ymax)
+      return 1.;
+    else
+      return 0.;
+  }
+    
+};
+
+int main (int argc, char** argv)
+{
+  std::string filename (argc > 1 ? argv[1] : "data/b9.ply");
+  std::ifstream in (filename.c_str());
+  std::vector<Point> pts;
+
+  std::cerr << "Reading input" << std::endl;
+  if (!in
+      || !(CGAL::read_ply_points (in, std::back_inserter (pts))))
+    {
+      std::cerr << "Error: cannot read " << filename << std::endl;
+      return EXIT_FAILURE;
+    }
+
+  Neighborhood neighborhood (pts, Pmap());
+  Local_eigen_analysis eigen (pts, Pmap(), neighborhood.k_neighbor_query(6));
+
+  Classifier classifier (pts, Pmap());
+
+  std::cerr << "Computing features" << std::endl;
+  Feature_handle sphericity = classifier.add_feature<Sphericity> (eigen);
+
+  // Feature that identifies points whose x coordinate is between -20
+  // and 20 and whose y coordinate is between -15 and 15
+  Feature_handle my_feature = classifier.add_feature<My_feature> (-20., 20., -15., 15.);
+                                                     
+  std::cerr << "Setting weights" << std::endl;
+  sphericity->set_weight(0.5);
+  my_feature->set_weight(0.25);
+
+  std::cerr << "Setting up labels" << std::endl;
+  Label_handle a = classifier.add_label ("label_A");
+  a->set_feature_effect (sphericity,  CGAL::Classification::Feature::FAVORING);
+  a->set_feature_effect (my_feature,  CGAL::Classification::Feature::FAVORING);
+
+  Label_handle b = classifier.add_label ("label_B");
+  b->set_feature_effect (sphericity,  CGAL::Classification::Feature::PENALIZING);
+  b->set_feature_effect (my_feature,  CGAL::Classification::Feature::PENALIZING);
+
+  classifier.run_with_graphcut (neighborhood.k_neighbor_query(12), 0.2);
+
+  std::cerr << "All done" << std::endl;
+  return EXIT_SUCCESS;
+}