nearest neighbor plugin (quick hack)

Plugin/CMakeLists.txt

@@ -23,7 +23,7 @@ set(SRC
   Probe.cpp MinMax.cpp
   HarmonicToTime.cpp ModulusPhase.cpp
   HomologyComputation.cpp
-  Distance.cpp ExtractEdges.cpp
+  Distance.cpp ExtractEdges.cpp NearestNeighbor.cpp
   AnalyseCurvedMesh.cpp
 )
 

Plugin/NearestNeighbor.cpp

+// Gmsh - Copyright (C) 1997-2010 C. Geuzaine, J.-F. Remacle
+//
+// See the LICENSE.txt file for license information. Please report all
+// bugs and problems to <gmsh@geuz.org>.
+
+#include "GmshConfig.h"
+#include "NearestNeighbor.h"
+
+#if defined(HAVE_ANN)
+#include "ANN/ANN.h"
+#endif
+
+StringXNumber NearestNeighborOptions_Number[] = {
+  {GMSH_FULLRC, "View", NULL, -1.},
+};
+
+extern "C"
+{
+  GMSH_Plugin *GMSH_RegisterNearestNeighborPlugin()
+  {
+    return new GMSH_NearestNeighborPlugin();
+  }
+}
+
+std::string GMSH_NearestNeighborPlugin::getHelp() const
+{
+  return "Plugin(NearestNeighbor) computes the distance from each "
+    "point in `View' to its nearest neighbor.\n\n"
+    "If `View' < 0, the plugin is run on the current view.\n\n"
+    "Plugin(NearestNeighbor) is executed in-place.";
+}
+
+int GMSH_NearestNeighborPlugin::getNbOptions() const
+{
+  return sizeof(NearestNeighborOptions_Number) / sizeof(StringXNumber);
+}
+
+StringXNumber *GMSH_NearestNeighborPlugin::getOption(int iopt)
+{
+  return &NearestNeighborOptions_Number[iopt];
+}
+
+PView *GMSH_NearestNeighborPlugin::execute(PView *v)
+{
+  int iView = (int)NearestNeighborOptions_Number[0].def;
+  
+  PView *v1 = getView(iView, v);
+  if(!v1) return v;
+  PViewData *data1 = v1->getData();
+
+  int totpoints = data1->getNumPoints();
+  if(!totpoints){
+    Msg::Error("View[%d] contains no points", v1->getNum());
+    return 0;
+  }
+
+#if defined(HAVE_ANN)
+  ANNpointArray zeronodes = annAllocPts(totpoints, 4);
+  int k = 0, step = 0;
+  for(int ent = 0; ent < data1->getNumEntities(step); ent++){
+    for(int ele = 0; ele < data1->getNumElements(step, ent); ele++){
+      if(data1->skipElement(step, ent, ele)) continue;
+      int numNodes = data1->getNumNodes(step, ent, ele);
+      if(numNodes != 1) continue;
+      data1->getNode(step, ent, ele, 0, zeronodes[k][0], zeronodes[k][1],
+                     zeronodes[k][2]);
+      k++;
+    }
+  }
+  ANNkd_tree *kdtree = new ANNkd_tree(zeronodes, totpoints, 3);
+  ANNidxArray index = new ANNidx[2];
+  ANNdistArray dist = new ANNdist[2];
+
+  v1->setChanged(true);
+  for(int ent = 0; ent < data1->getNumEntities(step); ent++){
+    for(int ele = 0; ele < data1->getNumElements(step, ent); ele++){
+      if(data1->skipElement(step, ent, ele)) continue;
+      int numNodes = data1->getNumNodes(step, ent, ele);
+      if(numNodes != 1) continue;
+      double xyz[3];
+      data1->getNode(step, ent, ele, 0, xyz[0], xyz[1], xyz[2]);
+      kdtree->annkSearch(xyz, 2, index, dist);
+      data1->setValue(step, ent, ele, 0, 0, sqrt(dist[1]));
+    }
+  }
+
+  delete kdtree;
+  annDeallocPts(zeronodes);
+  delete [] index;
+  delete [] dist;
+#endif
+
+  data1->setName(v1->getData()->getName() + "_NearestNeighbor");
+  data1->finalize();
+  
+  return v1;
+}

Plugin/NearestNeighbor.h

+// Gmsh - Copyright (C) 1997-2010 C. Geuzaine, J.-F. Remacle
+//
+// See the LICENSE.txt file for license information. Please report all
+// bugs and problems to <gmsh@geuz.org>.
+
+#ifndef _NEAREST_NEIGHBOR_H_
+#define _NEAREST_NEIGHBOR_H_
+
+#include "Plugin.h"
+
+extern "C"
+{
+  GMSH_Plugin *GMSH_RegisterNearestNeighborPlugin();
+}
+
+class GMSH_NearestNeighborPlugin : public GMSH_PostPlugin
+{
+ public:
+  GMSH_NearestNeighborPlugin(){}
+  std::string getName() const { return "NearestNeighbor"; }
+  std::string getShortHelp() const
+  {
+    return "Compute distance to the nearest neighbor";
+  }
+  std::string getHelp() const;
+  int getNbOptions() const;
+  StringXNumber *getOption(int iopt);  
+  PView *execute(PView *);
+};
+
+#endif

Plugin/PluginManager.cpp

@@ -30,6 +30,7 @@
 #include "Divergence.h"
 #include "Annotate.h"
 #include "Distance.h"
+#include "NearestNeighbor.h"
 #include "Remove.h"
 #include "MakeSimplex.h"
 #include "Smooth.h"
@@ -46,7 +47,6 @@
 #include "Probe.h"
 #include "GSHHS.h"
 #include "HomologyComputation.h"
-#include "Distance.h"
 #include "ExtractEdges.h"
 
 // for testing purposes only :-)
@@ -199,8 +199,6 @@ void PluginManager::registerDefaultPlugins()
                       ("Curl", GMSH_RegisterCurlPlugin()));
     allPlugins.insert(std::pair<std::string, GMSH_Plugin*>
                       ("Divergence", GMSH_RegisterDivergencePlugin()));
-    allPlugins.insert(std::pair<std::string, GMSH_Plugin*>
-		    ("Distance", GMSH_RegisterDistancePlugin()));
     allPlugins.insert(std::pair<std::string, GMSH_Plugin*>
                       ("Annotate", GMSH_RegisterAnnotatePlugin()));
     allPlugins.insert(std::pair<std::string, GMSH_Plugin*>
@@ -230,6 +228,10 @@ void PluginManager::registerDefaultPlugins()
 #if defined(HAVE_SOLVER)
     allPlugins.insert(std::pair<std::string, GMSH_Plugin*>
                       ("Distance", GMSH_RegisterDistancePlugin()));
+#endif
+#if defined(HAVE_ANN)
+    allPlugins.insert(std::pair<std::string, GMSH_Plugin*>
+                      ("NearestNeighbor", GMSH_RegisterNearestNeighborPlugin()));
 #endif
   }