Name space for various (mostly templated) chi-squared distribution functions. More...

Defines
#define	VNL_CHI_SQUARED_INSTANTIATE(T) extern "please include vnl/algo/vnl_chi_squared.txx first"
Functions
template<class T >
double	vnl_chi_squared_cumulative (T chisq, long dof)
	Compute cumulative distribution function value for chi-squared distribution.
template<class T >
double	vnl_chi_squared_statistic_1 (T const A, T const B, int n, bool normalize)
	Name space for various chi-squared distribution functions.
template<class T >
double	vnl_chi_squared_statistic_2 (T const A, T const B, int n, bool normalize)
	$\displaystyle \sum_i \frac{ (a[i] - b[i])^2 }{ b[i] }$
template<class T >
double	vnl_chi_squared_statistic_12 (T const A, T const B, int n, bool normalize)
	$\displaystyle \sum_i \frac{ (a[i] - b[i])^2 }{ a[i] + b[i] }$

Detailed Description

Name space for various (mostly templated) chi-squared distribution functions.

Author:: Rupert Curwen, GE CRD

Date:: August 18th, 1998

    Modifications
     26/03/2001   dac (Manchester) tidied up documentation
     24 Mar 2010  Peter Vanroose   made vnl_chi_squared_cumulative() templated

Definition in file vnl_chi_squared.h.

Define Documentation

#define VNL_CHI_SQUARED_INSTANTIATE ( T ) extern "please include vnl/algo/vnl_chi_squared.txx first"

Definition at line 65 of file vnl_chi_squared.h.

Function Documentation

template<class T >

double vnl_chi_squared_cumulative	(	T	chisq,
		long	dof
	)

Compute cumulative distribution function value for chi-squared distribution.

This subroutine computes the cumulative distribution function value for the chi-squared distribution with integer degrees of freedom parameter = dof. This distribution is defined for all non-negative chisq. Thus if a random variable x is drawn from a chi-squared distribution with d degrees of freedom, then $P(x < X) =$ vnl_chi_squared_cumulative(X,d). Internally, T=double is used.

Definition at line 19 of file vnl_chi_squared.txx.

template<class T >

double vnl_chi_squared_statistic_1	(	T const *	A,
		T const *	B,
		int	n,
		bool	normalize
	)

Name space for various chi-squared distribution functions.

A[] and B[] are (pointers to) arrays containing histograms. If the 'normalize' parameter is true, each histogram will be implicitly normalized (so as to sum to 1) before the statistic is calculated :

$a[i] = A[i] / \sum_j A[j]$