1 //                                               -*- C++ -*-
2 /**
3  *  @brief The test file of class NaiveNearestNeighbour for standard methods
4  *
5  *  Copyright 2005-2021 Airbus-EDF-IMACS-ONERA-Phimeca
6  *
7  *  This library is free software: you can redistribute it and/or modify
8  *  it under the terms of the GNU Lesser General Public License as published by
9  *  the Free Software Foundation, either version 3 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This library is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *  GNU Lesser General Public License for more details.
16  *
17  *  You should have received a copy of the GNU Lesser General Public License
18  *  along with this library.  If not, see <http://www.gnu.org/licenses/>.
19  *
20  */
21 #include "openturns/OT.hxx"
22 #include "openturns/OTtestcode.hxx"
23 
24 using namespace OT;
25 using namespace OT::Test;
26 
27 namespace
28 {
debug_squared_minimum_distance(const Point & point,const Sample & sample)29 UnsignedInteger debug_squared_minimum_distance(const Point & point, const Sample & sample)
30 {
31   Scalar result = SpecFunc::MaxScalar;
32   UnsignedInteger bestIndex = sample.getSize();
33   for(UnsignedInteger i = 0; i < sample.getSize(); ++i)
34   {
35     const Scalar distance2 = Point(sample[i] - point).normSquare();
36     if (distance2 < result)
37     {
38       result = distance2;
39       bestIndex = i;
40     }
41   }
42   return bestIndex;
43 }
44 }
45 
main(int,char * [])46 int main(int, char *[])
47 {
48   TESTPREAMBLE;
49   OStream fullprint(std::cout);
50 
51   const Sample sample(Normal().getSample(10));
52   const NearestNeighbour1D tree(sample);
53   fullprint << "tree=" << tree << std::endl;
54   const Sample test(Normal().getSample(20));
55   for (UnsignedInteger i = 0; i < test.getSize(); ++i)
56   {
57     const UnsignedInteger expected = debug_squared_minimum_distance(test[i], sample);
58     const UnsignedInteger index = tree.query(test[i]);
59     const Point neighbour(sample[tree.query(test[i])]);
60     fullprint << "Nearest neighbour of " << test[i] << "=" << neighbour << " (index=" << index << ")" << std::endl;
61     if (index != expected)
62     {
63       fullprint << "Wrong nearest neighbour of " << test[i] << " (index=" << index << ", expected=" << expected << ")" << std::endl;
64       return ExitCode::Error;
65     }
66   }
67 
68   const UnsignedInteger k = 4;
69   for (UnsignedInteger i = 0; i < test.getSize(); ++i)
70   {
71     Indices indices = tree.queryK(test[i], k, true);
72     fullprint << k << " nearest neighbours of " << test[i] << "=" << " (indices=" << indices << ")" << std::endl;
73     // Check that returned neighbours are sorted
74     Scalar last = 0.0;
75     for(UnsignedInteger j = 0; j < indices.getSize(); ++j)
76     {
77       const Scalar current = Point(test[i] - sample[indices[j]]).normSquare();
78       if (last > current)
79       {
80         fullprint << "Wrong nearest neighbour of " << test[i] << " (indices=" << indices << ")" << std::endl;
81         return ExitCode::Error;
82       }
83       last = current;
84     }
85   }
86 
87   return ExitCode::Success;
88 }
89