Is it possible to calculate the tail probablitlies of the chi-square distribution in MATLAB 7.11 (R2010b)?

I want to compute 1-chi2cdf(x,d) and the tail probability of a chi-square PDF. The function CHI2CDF cancels its value when its value is close to 1. In many cases I would like to have this value as I desire to set a threshold that is less than eps, machine epsilon.

Answer 1

[Michael]

You can get the upper tail probablities for the chi-square distribution uisng the code below:

chi2pval = @(x,nu) gammainc(x/2,v/2,'upper');