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accu/stat/var.cc
1 // Copyright (C) 2009 EPITA Research and Development Laboratory (LRDE)
2 //
3 // This file is part of Olena.
4 //
5 // Olena is free software: you can redistribute it and/or modify it under
6 // the terms of the GNU General Public License as published by the Free
7 // Software Foundation, version 2 of the License.
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12 // General Public License for more details.
13 //
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15 // along with Olena. If not, see <http://www.gnu.org/licenses/>.
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17 // As a special exception, you may use this file as part of a free
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19 // instantiate templates or use macros or inline functions from this
20 // file, or you compile this file and link it with other files to produce
21 // an executable, this file does not by itself cause the resulting
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24 // executable file might be covered by the GNU General Public License.
25 
26 #include <cstdlib>
27 #include <mln/accu/stat/var.hh>
28 
29 
30 float my_rand(int c)
31 {
32  return (1 + c) * float(std::rand()) / RAND_MAX;
33 }
34 
35 
36 int main()
37 {
38  using namespace mln;
39 
40  typedef algebra::vec<3,float> vec3f;
41 
42  enum { n = 1000 };
43  vec3f v[n];
44 
45  for (int i = 0; i < n; ++i)
46  {
47  v[i][0] = my_rand(0);
48  v[i][1] = my_rand(1);
49  v[i][2] = my_rand(2);
50  }
51 
53  for (int i = 0; i < n; ++i)
54  a.take(v[i]);
55 
56  mln_assertion(a.n_items() == n);
57 
58  vec3f m = a.mean();
59  mln_assertion(m[0] > 0.4 && m[0] < 0.6);
60  mln_assertion(m[1] > 0.9 && m[1] < 1.1);
61  mln_assertion(m[2] > 1.4 && m[2] < 1.6);
62 
63  algebra::mat<3,3,float> s_1 = a.variance()._1();
64  mln_assertion(s_1(0,0) > 11 && s_1(0,0) < 13);
65  mln_assertion(s_1(1,1) > 2 && s_1(1,1) < 4);
66  mln_assertion(s_1(2,2) > 1.1 && s_1(2,2) < 1.5);
67 }