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/*
//
// Copyright 1997-2009 Torsten Rohlfing
// Copyright 2004-2009 SRI International
//
// This file is part of the Computational Morphometry Toolkit.
//
// http://www.nitrc.org/projects/cmtk/
//
// The Computational Morphometry Toolkit 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 3 of
// the License, or (at your option) any later version.
//
// The Computational Morphometry Toolkit 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 the Computational Morphometry Toolkit. If not, see
// <http://www.gnu.org/licenses/>.
//
// $Revision: 2398 $
//
// $LastChangedDate: 2010-10-05 14:54:37 -0700 (Tue, 05 Oct 2010) $
//
// $LastChangedBy: torstenrohlfing $
//
*/
#include <iostream>
#include <Base/cmtkMathUtil.h>
// test whether uniform random numbers are reasonably uniform; does NOT test whether they are random!
int
testMathUtilUniformRandom()
{
const size_t nSamples = 100000;
const size_t nBins = 50;
unsigned int histogram[nBins];
memset( histogram, 0, sizeof( histogram ) );
for ( size_t n = 0; n < nSamples; ++n )
{
++histogram[static_cast<size_t>( nBins * cmtk::MathUtil::UniformRandom() )];
}
// allow +/- 5% deviation in each bin. This seems to be what Numerical Recipes can do.
const unsigned int lower = static_cast<unsigned int>( 0.95 * nSamples / nBins );
const unsigned int upper = static_cast<unsigned int>( 1.05 * nSamples / nBins );
unsigned int countOutside = 0;
for ( size_t n = 0; n < nBins; ++n )
{
if ( (histogram[n] < lower ) || (histogram[n] > upper ) )
++countOutside;
}
const unsigned int threshold = static_cast<unsigned int>( 0.05 * nBins );
if ( countOutside > threshold )
{
std::cerr << "Too many bins outside +/- 5% range. Actual: " << countOutside << ", threshold: " << threshold << std::endl;
return 1;
}
return 0;
}
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