File: histogram_test.cpp

package info (click to toggle)
libitpp 4.0.4-2
  • links: PTS, VCS
  • area: main
  • in suites: lenny
  • size: 7,520 kB
  • ctags: 6,341
  • sloc: cpp: 51,608; sh: 9,248; makefile: 636; fortran: 8
file content (113 lines) | stat: -rw-r--r-- 3,821 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
/*!
 * \file
 * \brief Histogram class test program
 * \author Andy Panov and Adam Piatyszek
 *
 * -------------------------------------------------------------------------
 *
 * IT++ - C++ library of mathematical, signal processing, speech processing,
 *        and communications classes and functions
 *
 * Copyright (C) 1995-2008  (see AUTHORS file for a list of contributors)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * -------------------------------------------------------------------------
 */

#include <itpp/itstat.h>
#include <iomanip>

using namespace itpp;
using namespace std;


void display_pdf(Histogram<double>& hist)
{
  cout.setf(ios::fixed);

  const int max_asterisks_per_line = 40;
  ivec bins = hist.get_bins();

  // compute and display experimental PDF
  vec exp_pdf = hist.get_pdf();
  double pdf_max = max(exp_pdf);

  cout << "  bin | count |     PDF |" << endl
       << "------+-------+---------+-------------------------------------------"
       << endl;
  for (int i = 0; i < exp_pdf.length(); i++) {
    int num_asterisks = static_cast<int>(exp_pdf(i) * max_asterisks_per_line
					 / pdf_max);
    cout << setw(5) << setprecision(1) << round_to_zero(hist.get_bin_center(i))
	 << " | " << setw(5) << hist.get_bin(i) << " | "
	 << setw(7) << setprecision(5) << round_to_zero(exp_pdf(i)) << " | ";
    for (int j = 0; j < num_asterisks; j++) {
      cout << "*";
    }
    cout << endl;
  }
  cout << "------+-------+---------+-------------------------------------------"
       << endl;
  cout << "Histogram trials counter  : " << sum(hist.get_bins()) << endl;
  cout << "Sum of the histogram bins : " << sum(hist.get_bins()) << endl;
  cout << "Sum of PDF values         : " << sum(exp_pdf) << endl;
  cout << "--------------------------------------------------------------------"
       << endl << endl;
}


int main()
{
  cout << "=======================" << endl;
  cout << "    Histogram tests    " << endl;
  cout << "=======================" << endl << endl;

  // create histogram
  Histogram<double> hist(-3, 3, 21);

  // matrix dimension for statistical test
  int mat_dim = 100;

  cout << "Experimental PDF of " << mat_dim << "x" << mat_dim
       << " normal distributed random matrix:" << endl << endl;

  // compute histogram for a random matrix
  hist.update(randn(mat_dim, mat_dim));
  display_pdf(hist);

  // reset histogram, so we can start next experiment
  hist.reset();

  // compute histogram for a random vector
  int num_stat_trials = 50000;

  cout << "Experimental PDF of "<< num_stat_trials
       << " normal distributed random variables:" << endl << endl;

  // compute histogram for random vector
  hist.update(randn(num_stat_trials));
  display_pdf(hist);

  // compute CDF. CDF is computed vs. right bin boundaries
  cout << "Experimental CDF (CDF(x) = Pr(a < x), a - random variable) " << endl
       << "of the same vector:" << endl << endl;
  vec exp_cdf = hist.get_cdf();
  for (int i = 0; i < exp_cdf.length(); i++)
    cout << "CDF(" << setw(5) << setprecision(2) << hist.get_bin_right(i)
	 << ") = " << setw(6) << setprecision(4) << exp_cdf(i) << endl;

  return 0;
}