AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

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David Soltysik
February 11, 2003 01:28PM
If anyone is still curious, I've determined the simple way to do this using the incomplete beta function in MATLAB.

r to p-value
============

x=1-r^2;
n=number of samples;

p=betainc(x,0.5*(n-2),0.5);


F-value to p-value
==================
F=F-value;
v1=numerator degrees of freedom
v2=denominator degrees of freedom
x=v2/(v2+v1*F);

p=betainc(x,v2/2,v1/2);




The F-value transformation can be found as equation 26.6.2 in Abramowitz and Stegun. 1972. Handbook of Mathematical Functions. Dover, New York.

The other one was determined by looking at c-code and does not include fit or orthogonal parameters.
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Subject Author Posted

Test statistic to p-value (cdf)

David Soltysik January 23, 2003 10:57AM

Re: Test statistic to p-value (cdf)

bob cox January 23, 2003 01:21PM

Re: Test statistic to p-value (MATLAB)

David Soltysik February 11, 2003 01:28PM