Name

chis_pdf — chi-squared probability distribution

CALLING SEQUENCE

[f]=chis_pdf(x,a)

PARAMETERS

Input

• x = a (nxm) matrix

• a = a scalar or a (nxm) matrix

Output

• f = a matrix of pdf at each element of x from chisq(a) or chisq(same element of a) distribution

DESCRIPTION

Returns the pdf at x of the chi-squared(n) distribution. NOTE: chis_pdf(x,n) = gamm_pdf(x/2,n/2)/2

EXAMPLE

1) y=chis_pdf([1:4],2)
2) y=chis_pdf([1:4],2*ones(1,4))
 
Examples 1 and 2 do exactly the same thing: they provide the (1x4) vectors of probabilities that a chi-square is greater than 1, 2, 3 and 4 respectively. 

               

AUTHOR

Eric Dubois 2002