histogram< T > Class Template Reference

Count instances in 1D. Equally spaced intervals except the end intervals (-infinty,xlow) and (xhigh,infinity). More...

#include <histogram.h>

Inheritance diagram for histogram< T >:

Collaboration diagram for histogram< T >:

List of all members.

Public Member Functions
void	reset ()
	Sets counts to zero.
	histogram (T const xlow_, T const xhigh_, uintc N_)
	Constructor defines the intervals.
void	eval (T const x)
	Count the instance.
void	frequencydist (vector< T > &vd, boolc exclude_low=true, boolc exclude_high=true) const
	Construct a frequency distribution from data.
void	frequencydistpair (vector< T > &vd, boolc exclude_low=true, boolc exclude_high=true) const
	Interlace the middle of the range and the frequency distribution.
ostream &	printfrequencydistpair (ostream &os, boolc exclude_low=true, boolc exclude_high=true) const
	Same as frequencydistpair but prints a return after each pair.
ostream &	print (ostream &os) const
	Prints the counter including lowest and highest intervals.
Public Attributes
vector< T >	counter
	Keeps interval counts.

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Detailed Description

template<typename T>
class histogram< T >

Count instances in 1D. Equally spaced intervals except the end intervals (-infinty,xlow) and (xhigh,infinity).

xlow is the lowest partition point. xhigh is the highest partition point. N is the number of inner divisions. ie N-1 partitions between xlow and xhigh. The other two partitions are for x>xhigh and x<xlow. n+1 partitions in total.

Definition at line 23 of file histogram.h.

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Constructor & Destructor Documentation

template<typename T>

histogram< T >::histogram	(	T const	xlow_,
		T const	xhigh_,
		uintc	N_
	)			[inline]

Constructor defines the intervals.

Definition at line 200 of file histogram.h.

References reset().

  : xlow(xlow_), xhigh(xhigh_), N(N_)
{
  assert(xlow<xhigh);
  assert(N>0);

  dw = (N-1.0)/(xhigh-xlow);
  reset();
}

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Member Function Documentation

template<typename T>

void histogram< T >::eval

(

T const

x

)

[inline]

Count the instance.

Definition at line 91 of file histogram.h.

References histogram< T >::counter.

Referenced by histogramtest::test01().

{
  assert(counter.size()==N+1);
  assert(N>0);
  if ((xlow<x)&&(x<xhigh))
  {
    uint k = (uint)((x-xlow)*dw+1);
    ++counter[k];
    return;
  }

  if ((xlow<x)==false)
  {
    ++counter[0];
    return;
  }

  ++counter[N];
}

template<typename T>

void histogram< T >::frequencydist	(	vector< T > &	vd,
		boolc	exclude_low = true,
		boolc	exclude_high = true
	)			const [inline]

Construct a frequency distribution from data.

ie c[i]/sum(c[i])

Definition at line 157 of file histogram.h.

Referenced by histogramtest::test01().

{
  if (counter.empty()||(N<3))
    return;

  uint i=0;
  uint imax=counter.size();
  if (exclude_low)
    ++i;

  if (exclude_high)
    --imax;

  T sum = 0;
  for (uint k=i;k<imax;++k)
    sum += counter[k];

  vd.resize(imax-i);

  if (sum==0)
    return;

  T suminv = T(1.0) / sum;
  for (uint k=i;k<imax;++k)
    vd[k-i] = counter[k]*suminv;
}

template<typename T>

void histogram< T >::frequencydistpair	(	vector< T > &	vd,
		boolc	exclude_low = true,
		boolc	exclude_high = true
	)			const [inline]

Interlace the middle of the range and the frequency distribution.

Useful for plots.

Definition at line 133 of file histogram.h.

{
  if (counter.empty()||(N<3))
    return;

  vector<T> v;
  frequencydist(v,exclude_low,exclude_high);

  uintc imax = v.size();
  vd.resize(imax*2);
  for (uint i=0; i<imax; ++i)
  {
    vd[i*2] = xlow+(xhigh-xlow)*(.5+i)/(N-1);
    vd[i*2+1] = v[i];
  }

}

template<typename T >

ostream & histogram< T >::print

(

ostream &

os

)

const [inline]

Prints the counter including lowest and highest intervals.

Definition at line 189 of file histogram.h.

References histogram< T >::counter.

{
  uint imax = counter.size();
  for (uint i=0; i<imax; ++i)
    os << counter[i] << " ";

  return os;
}

template<typename T >

ostream & histogram< T >::printfrequencydistpair	(	ostream &	os,
		boolc	exclude_low = true,
		boolc	exclude_high = true
	)			const [inline]

Same as frequencydistpair but prints a return after each pair.

Definition at line 113 of file histogram.h.

Referenced by histogramtest::test01().

{
  vector<T> fd;
  frequencydistpair(fd,exclude_low,exclude_high);
  uint imax=fd.size()/2;
  for (uint i=0; i<imax; ++i)
  {
    os << fd[2*i] << " ";
    os << fd[2*i+1] << endl;
  }

  return os;
}

template<typename T >

void histogram< T >::reset

(

)

[inline]

Sets counts to zero.

Definition at line 215 of file histogram.h.

References histogram< T >::counter.

{
  counter.resize(N+1);
  assert(counter.size()==N+1);
  uintc imax=counter.size();

  for (uint i=0; i<imax; ++i)
    counter[i]=0;
}

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Member Data Documentation

template<typename T>

vector<T> histogram< T >::counter

Keeps interval counts.

Definition at line 32 of file histogram.h.

Referenced by histogram< T >::eval(), histogram< T >::print(), and histogram< T >::reset().

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The documentation for this class was generated from the following file:

• mathlib/histogram.h