--- /dev/null
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2017 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE at
+// the top level of the deal.II distribution.
+//
+//---------------------------------------------------------------------
+
+// Create a list of points, and compute the minimum distance from some other points
+// to this set, using a kdtree library
+
+#include <deal.II/base/logstream.h>
+#include <deal.II/numerics/kdtree.h>
+
+
+int main ()
+{
+ KDTree<2> kdtree;
+
+ std::vector<Point<2> > points;
+
+ // Add four points
+ points.push_back(Point<2>(0,0));
+ points.push_back(Point<2>(0,1));
+ points.push_back(Point<2>(1,0));
+ points.push_back(Point<2>(1,1));
+
+ deallog << "Distance from unit square:" << std::endl;
+
+ std::vector<Point<2> > test_points;
+ test_points.push_back(Point<2>(.5, .5));
+ test_points.push_back(Point<2>(2, 0));
+ test_points.push_back(Point<2>(2, 2));
+
+ kdtree.set_points(points);
+
+ for (auto &p : test_points)
+ {
+ auto res = kdtree.get_closest_points(p,1)[0];
+ deallog << "P: " << p << ", distance: " << res.second << ", index: " << res.first << std::endl;
+ }
+
+ deallog << "Consistency checking: the following are all the points in the set." << std::endl;
+ for (auto &p : points)
+ {
+ auto res = kdtree.get_closest_points(p,1)[0];
+ deallog << "P: " << p << ", distance: " << res.second << ", index: " << res.first << std::endl;
+ Assert(res.second < 1e-10, ExcMessage("Should be zero!"));
+ }
+}