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Heavily refactored the whole structure. 

Some interfaces have been changed. Be careful.
This commit is contained in:
Paolo Cignoni 2008-03-05 11:21:49 +00:00
parent 14dee656f3
commit 051c612aba
1 changed files with 123 additions and 70 deletions
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193
vcg/math/histogram.h
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@ -24,6 +24,9 @@
History
$Log: not supported by cvs2svn $
Revision 1.17 2008/02/29 12:15:06 cignoni
added maxcount
Revision 1.16 2006/11/28 21:29:21 cignoni
Re added typedef Histogramf and Histogramd
@ -98,54 +101,44 @@ class Histogram
{
// public data members
public:
private:
//! Counters for bins.
std::vector <int> H;
//! Range for bins.
std::vector <ScalarType> R;
std::vector <int> H; //! Counters for bins.
std::vector <ScalarType> R; //! Range for bins.
ScalarType minv; //! Minimum value.
ScalarType maxv; //! Maximum value.
int n; //! Number of vaild intervals stored between minv and maxv.
//! Minimum value.
ScalarType minv;
//! Maximum value.
ScalarType maxv;
/// incrementally updated values
int cnt; //! Number of accumulated samples.
ScalarType avg; //! Average.
ScalarType rms; //! Root mean square.
//! Number of intervals.
int n;
//! Number of accumulated samples.
int cnt;
//! Average.
ScalarType avg;
//! Root mean square.
ScalarType rms;
/**
* Returns the index of the bin which contains a given value.
*/
int BinIndex(ScalarType val) ;
// public methods
public:
/**
* Set the histogram values.
*
* This method is used to correctly initialize the bins of the histogram.
* n is the number of valid intervals between minv and maxv.
* for a more robust working, the Histogram class stores also the two out of range intervals (-inf, minv] and [maxv, +inf)
* Each bin is left closed (eg it contains the value
* The \a gamma parameter is applied to modify the distribution of the ranges of the bins. Default uniform distibution.
*
*/
void SetRange(ScalarType _minv, ScalarType _maxv, int _n);
void SetRange(ScalarType _minv, ScalarType _maxv, int _n,ScalarType gamma=1.0 );
/**
* Set the histogram values.
*
* This method is used to correctly initialize the bins of the histogram.
* The \a gamma parameter is applied to modify the ranges of the bins.
*/
void SetRange(ScalarType _minv, ScalarType _maxv, int _n, ScalarType gamma);
ScalarType MinV() {return minv;}; //! Minimum value.
ScalarType MaxV() {return maxv;}; //! Minimum value.
/**
* Returns the index of the bin which contains a given value.
*/
int Interize(ScalarType val);
/**
* Add a new value to the histogram.
@ -156,6 +149,11 @@ public:
void Add(ScalarType v);
int MaxCount() const;
int BinCount(ScalarType v);
int BinCount(ScalarType v, ScalarType width);
int RangeCount(ScalarType rangeMin, ScalarType rangeMax);
ScalarType BinWidth(ScalarType v);
/**
* Returns the value corresponding to a given percentile of the data.
*
@ -195,23 +193,22 @@ void Histogram<ScalarType>::Clear()
maxv=1;
}
/*
Note that the histogram holds <n> valid bins plus two semi-infinite bins.
template <class ScalarType>
void Histogram<ScalarType>::SetRange(ScalarType _minv, ScalarType _maxv, int _n)
{
// reset data
Clear();
R[0] = -inf
R[1] = minv
R[n+1] = maxv
R[n+2] = +inf
// set bins
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;
}
Eg. SetRange(0, 10, 5) asks for 5 intervals covering the 0..10 range
H[0] H[1] H[2] H[3] H[4] H[5] H[6]
-inf 0 2 4 6 8 10 +inf
R[0] R[1] R[2] R[3] R[4] R[5] R[6] R[7]
*/
template <class ScalarType>
void Histogram<ScalarType>::SetRange(ScalarType _minv, ScalarType _maxv, int _n, ScalarType gamma)
@ -220,31 +217,61 @@ void Histogram<ScalarType>::SetRange(ScalarType _minv, ScalarType _maxv, int _n,
Clear();
minv=_minv;maxv=_maxv;n=_n;
H.resize(n+1);
H.resize(n+2);
fill(H.begin(),H.end(),0);
R.resize(n+1);
R.resize(n+3);
double dlt=(maxv-minv);
for(int i=0;i<n+1;++i)
R[i]=minv+dlt*pow(ScalarType(i)/n,gamma);
R[0] = - std::numeric_limits< ScalarType >::max();
R[n+2] = std::numeric_limits< ScalarType >::max();
double delta=(maxv-minv);
if(gamma==1)
{
for(int i=0; i<=n; ++i)
R[i+1] = minv + delta*ScalarType(i)/n;
}
else
{
for(int i=0; i<=n; ++i)
R[i+1] = minv + delta*pow(ScalarType(i)/n,gamma);
}
}
template <class ScalarType>
int Histogram<ScalarType>::Interize(ScalarType val)
int Histogram<ScalarType>::BinIndex(ScalarType val)
{
int pos = lower_bound(R.begin(),R.end(),val) - R.begin() - 1;
if (pos>n) pos=n;
// lower_bound returns the furthermost iterator i in [first, last) such that, for every iterator j in [first, i), *j < value.
// E.g. An iterator pointing to the first element "not less than" val, or end() if every element is less than val.
typename std::vector<ScalarType>::iterator it = lower_bound(R.begin(),R.end(),val);
assert(it!=R.begin());
assert(it!=R.end());
assert((*it)>=val);
int pos = it-R.begin();
assert(pos >=1);
pos -= 1;
assert (R[pos] < val);
assert ( val <= R[pos+1] );
return pos;
}
/*
H[0] H[1] H[2] H[3] H[4] H[5] H[6]
-inf 0 2 4 6 8 10 +inf
R[0] R[1] R[2] R[3] R[4] R[5] R[6] R[7]
asking for 3.14 lower bound will return an iterator pointing to R[3]==4; and will increase H[2]
asking for 4 lower bound will return an iterator pointing to R[3]==4; and will increase H[2]
*/
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)
int pos=BinIndex(v);
if(pos>=0 && pos<=n)
{
++H[pos];
++cnt;
@ -253,6 +280,35 @@ void Histogram<ScalarType>::Add(ScalarType v)
}
}
template <class ScalarType>
int Histogram<ScalarType>::BinCount(ScalarType v)
{
return H[BinIndex(v)];
}
template <class ScalarType>
int Histogram<ScalarType>::BinCount(ScalarType v, ScalarType width)
{
return RangeCount(v-width/2.0,v+width/2.0);
}
template <class ScalarType>
int Histogram<ScalarType>::RangeCount(ScalarType rangeMin, ScalarType rangeMax)
{
int firstBin=BinIndex(rangeMin);
int lastBin=BinIndex (rangeMax);
int sum=0;
for(int i=firstBin; i<=lastBin;++i)
sum+=H[i];
return sum;
}
template <class ScalarType>
ScalarType Histogram<ScalarType>::BinWidth(ScalarType v)
{
int pos=BinIndex(v);
return R[pos+1]-R[pos];
}
template <class ScalarType>
void Histogram<ScalarType>::FileWrite(const std::string &filename)
@ -273,7 +329,9 @@ int Histogram<ScalarType>::MaxCount() const
return *(std::max_element(H.begin(),H.end()));
}
// Return the scalar value <r> such that there are <frac> samples <= <r>.
// E.g. Percentile(0.0) will return R[1] e.g. min value
// E.g. Percentile(1.0) will return R[n+1] e.g max value
template <class ScalarType>
ScalarType Histogram<ScalarType>::Percentile(ScalarType frac) const
@ -285,26 +343,21 @@ ScalarType Histogram<ScalarType>::Percentile(ScalarType frac) const
assert(frac >= 0 && frac <= 1);
ScalarType sum=0,partsum=0;
int isum=0;
int i;
for(i=0;i<n+1;i++)
{
sum+=H[i];
isum+=H[i];
}
// check
assert(isum==cnt);
// useless summation just to be sure
for(i=0;i<H.size();i++) sum+=H[i];
assert(sum==cnt);
sum*=frac;
for(i=0; i<n; i++)
for(i=0; i<H.size(); i++)
{
partsum+=H[i];
if(partsum>=sum) break;
}
assert(i<H.size());
return R[i+1];
}