00001 // Copyright (C) 2009 EPITA Research and Development Laboratory (LRDE) 00002 // 00003 // This file is part of Olena. 00004 // 00005 // Olena is free software: you can redistribute it and/or modify it under 00006 // the terms of the GNU General Public License as published by the Free 00007 // Software Foundation, version 2 of the License. 00008 // 00009 // Olena is distributed in the hope that it will be useful, 00010 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00012 // General Public License for more details. 00013 // 00014 // You should have received a copy of the GNU General Public License 00015 // along with Olena. If not, see <http://www.gnu.org/licenses/>. 00016 // 00017 // As a special exception, you may use this file as part of a free 00018 // software project without restriction. Specifically, if other files 00019 // instantiate templates or use macros or inline functions from this 00020 // file, or you compile this file and link it with other files to produce 00021 // an executable, this file does not by itself cause the resulting 00022 // executable to be covered by the GNU General Public License. This 00023 // exception does not however invalidate any other reasons why the 00024 // executable file might be covered by the GNU General Public License. 00025 00026 #include <cstdlib> 00027 #include <mln/accu/stat/var.hh> 00028 #include <mln/fun/stat/mahalanobis.hh> 00029 00030 00031 float my_rand(int c) 00032 { 00033 return (1 + c) * float(std::rand()) / RAND_MAX; 00034 } 00035 00036 00037 int main() 00038 { 00039 using namespace mln; 00040 00041 typedef algebra::vec<3,float> vec3f; 00042 00043 enum { n = 1000 }; 00044 vec3f v[n]; 00045 00046 for (int i = 0; i < n; ++i) 00047 { 00048 v[i][0] = my_rand(0); 00049 v[i][1] = my_rand(1); 00050 v[i][2] = my_rand(2); 00051 } 00052 00053 accu::stat::var<vec3f> a; 00054 for (int i = 0; i < n; ++i) 00055 a.take(v[i]); 00056 00057 fun::stat::mahalanobis<vec3f> f(a.variance(), a.mean()); 00058 mln_assertion(f(a.mean()) == 0.f); 00059 00060 float sum = 0.f; 00061 for (int i = 0; i < n; ++i) 00062 { 00063 float f_ = f(v[i]); 00064 sum += f_ * f_; 00065 } 00066 mln_assertion(std::abs(sum / n - 3.f) < 0.00002f); 00067 }