/usr/include/mia-2.2/mia/core/meanvar.hh is in libmia-2.2-dev 2.2.2-1+b1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | /* -*- mia-c++ -*-
*
* This file is part of MIA - a toolbox for medical image analysis
* Copyright (c) Leipzig, Madrid 1999-2014 Gert Wollny
*
* MIA 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.
*
* 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 MIA; if not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef mia_core_meanvar_hh
#define mia_core_meanvar_hh
#include <map>
#include <cmath>
#include <mia/core/defines.hh>
NS_MIA_BEGIN
/**
\ingroup misc
Evaluate the mean and the variance of a series of scalars
\tparam ForwardIterator
\param begin
\param end
\returns mean as .first and variance as .second of the std::pair.
\todo could be extended to vector types
*/
template <typename ForwardIterator>
std::pair<double, double> mean_var(ForwardIterator begin, ForwardIterator end)
{
std::pair<double, double> result;
result.first = 0.0;
result.second = 0.0;
size_t n = 0;
while (begin != end) {
const double help = *begin;
result.first += help;
result.second += help * help;
++n;
++begin;
}
if (n > 0)
result.first /= n;
if (n > 1)
result.second = sqrt((result.second - n * result.first * result.first) / (n - 1));
else
result.second = 0.0;
return result;
}
NS_MIA_END
#endif
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