vcglib/vcg/math/histogram.h

188 lines
5.6 KiB
C++

/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* 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 (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
* *
****************************************************************************/
/****************************************************************************
History
$Log: not supported by cvs2svn $
Revision 1.9 2005/06/14 14:27:00 ganovelli
added include of algorithm
Revision 1.8 2005/06/10 14:59:39 cignoni
Added include assert.h and cast to ScalarType for a pow in SetRange() function.
Revision 1.7 2005/06/09 14:19:55 cignoni
Added typedef Histogramf and Histogramd
Revision 1.6 2005/06/07 09:37:33 ponchio
Added fabs() to variance, which can sometime be negative in case
of rounding errors (and sqrt chokes on it).
Revision 1.5 2005/06/07 07:44:08 cignoni
Added Percentile and removed small bug in Add
Revision 1.4 2005/04/04 10:48:35 cignoni
Added missing functions Avg, rms etc, now fully (almost) functional
Revision 1.3 2005/03/14 09:23:40 cignoni
Added missing include<vector>
Revision 1.2 2004/08/25 15:15:26 ganovelli
minor changes to comply gcc compiler (typename's and stuff)
Revision 1.1 2004/06/24 09:12:28 cignoni
Initial Release
****************************************************************************/
#ifndef __VCG_HISTOGRAM
#define __VCG_HISTOGRAM
#include <vector>
#include <algorithm>
#include <assert.h>
namespace vcg {
/**
*/
template <class ScalarType>
class Histogram {
public:
std::vector <int> H; /// counters for bins
std::vector <ScalarType> R; /// Range for bins (
ScalarType minv;
ScalarType maxv;
int n; // numero di intervalli
int cnt; // numero di campioni accumulati
ScalarType avg;
ScalarType rms;
void SetRange(ScalarType _minv, ScalarType _maxv, int _n);
void SetRange(ScalarType _minv, ScalarType _maxv, int _n, ScalarType gamma);
int Interize(ScalarType val);
void Add(ScalarType v);
ScalarType Percentile(ScalarType frac) const;
ScalarType Avg() { return avg/cnt; }
ScalarType RMS() { return sqrt(rms/double(cnt));}
ScalarType Variance() { return fabs(rms/cnt-Avg()*Avg()); }
ScalarType StandardDeviation() { return sqrt(Variance()); }
void FileWrite(const std::string &filename);
void Clear();
};
template <class ScalarType>
void Histogram<ScalarType> ::Clear()
{
H.clear();
R.clear();
cnt=0;
avg=0;
rms=0;
n=0;
minv=0;
maxv=1;
}
template <class ScalarType>
void Histogram<ScalarType>::SetRange(ScalarType _minv, ScalarType _maxv, int _n)
{
Clear();
minv=_minv;maxv=_maxv;n=_n;
H.resize(n+1);
fill(H.begin(),H.end(),0);
R.resize(n+1);
ScalarType dlt=(maxv-minv)/n;
for(int i=0;i<n+1;++i)
R[i]=minv+dlt*i;
}
template <class ScalarType>
void Histogram<ScalarType>::SetRange(ScalarType _minv, ScalarType _maxv, int _n, ScalarType gamma)
{
Clear();
minv=_minv;maxv=_maxv;n=_n;
H.resize(n+1);
fill(H.begin(),H.end(),0);
R.resize(n+1);
double dlt=(maxv-minv);
for(int i=0;i<n+1;++i)
R[i]=minv+dlt*pow(ScalarType(i)/n,gamma);
}
template <class ScalarType>
int Histogram<ScalarType>::Interize(ScalarType val)
{
int pos = lower_bound(R.begin(),R.end(),val) - R.begin() - 1;
if(pos>n) pos=n;
return pos;
}
template <class ScalarType>
void Histogram<ScalarType>::Add(ScalarType v){
int pos= lower_bound(R.begin(),R.end(),v)-R.begin()-1;
if(pos>=0 && pos<=n){
++H[pos];
++cnt;
avg+=v;
rms += v*v;
}
}
template <class ScalarType>
void Histogram<ScalarType>::FileWrite(const std::string &filename){
FILE *fp;
fp=fopen(filename.c_str(),"w");
for(int i=0;i<H.size();i++)
fprintf (fp,"%12.8lf , %12.8lf \n",R[i],double(H[i])/cnt);
}
template <class ScalarType>
ScalarType Histogram<ScalarType>::Percentile(ScalarType frac) const
{
if(H.size()==0 && R.size()==0) return 0;
assert(frac>=0 && frac<=1);
ScalarType sum=0,partsum=0;
int isum=0,ipartsum=0;
int i;
for(i=0;i<n+1;i++) { sum+=H[i]; isum+=H[i];}
assert(isum==cnt);
assert(sum==cnt);
sum*=frac;
for(i=0;i<n;i++) {
partsum+=H[i];
if(partsum>=sum) break;
}
return R[i+1];
}
typedef Histogram<double> Histogramd ;
typedef Histogram<float> Histogramf ;
}// end namespace
#endif