Changeset 10211 for branches/HeuristicLab.Analysis.AlgorithmBehavior/HeuristicLab.Analysis.AlgorithmBehavior.Analyzers

Timestamp:

12/09/13 22:42:34 (11 years ago)

Author:

ascheibe

Message:

#1886 added a wrapper for calculating the convex hull using qhull

Location:

branches/HeuristicLab.Analysis.AlgorithmBehavior/HeuristicLab.Analysis.AlgorithmBehavior.Analyzers/3.3

Files:

• HeuristicLab.Analysis.AlgorithmBehavior.Analyzers-3.3.csproj (modified) (1 diff)
• QhullWrapper.cs (modified) (2 diffs)

branches/HeuristicLab.Analysis.AlgorithmBehavior/HeuristicLab.Analysis.AlgorithmBehavior.Analyzers/3.3/HeuristicLab.Analysis.AlgorithmBehavior.Analyzers-3.3.csproj

@@ -22 +22 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">

branches/HeuristicLab.Analysis.AlgorithmBehavior/HeuristicLab.Analysis.AlgorithmBehavior.Analyzers/3.3/QhullWrapper.cs

@@ -20 +20 @@
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -42 +43 @@
     }
 
+    public unsafe static List<int> CalculateConvexHull(List<double[]> points) {
+      int dimension = points.First().Length;
+      int numPoints = points.Count();
+      List<int> convexHullIndices = new List<int>();
+
+      double[] data = new double[dimension * numPoints];
+      for (int i = 0; i < numPoints; i++) {
+        for (int j = 0; j < dimension; j++) {
+          data[i * dimension + j] = points[i][j];
+        }
+      }
+
+      IntPtr result = IntPtr.Zero;
+      Int32 nrOfFacets = -1;
+      Int32 retCode = 0;
+
+      result = qhull_convex_hull(dimension, numPoints, data, &retCode, &nrOfFacets);
+      if (result != IntPtr.Zero && retCode == 0) {
+        try {
+          var faces = new int[nrOfFacets * dimension];
+          Marshal.Copy(result, faces, 0, nrOfFacets * dimension);
+          convexHullIndices.AddRange(faces.Distinct());
+        }
+        finally {
+          qhull_free(result);
+        }
+      }
+      return convexHullIndices;
+    }
+
     [System.Runtime.InteropServices.DllImportAttribute("HeuristicLab.qhull.dll", EntryPoint = "qhull_volume", CallingConvention = CallingConvention.Cdecl)]
     public static extern double qhull_volume(int dim, int numpoints, [In]double[] data);
+
+    [System.Runtime.InteropServices.DllImportAttribute("HeuristicLab.qhull.dll", EntryPoint = "qhull_convex_hull", CallingConvention = CallingConvention.Cdecl)]
+    public unsafe static extern IntPtr qhull_convex_hull(int dim, int numpoints, [In]double[] data, [Out] Int32* retCode, [Out] Int32* nrOfFacets);
+
+    [System.Runtime.InteropServices.DllImportAttribute("HeuristicLab.qhull.dll", EntryPoint = "qhull_free", CallingConvention = CallingConvention.Cdecl)]
+    public static extern void qhull_free(IntPtr data);
   }
 }