I have seen in nmath directory that (dpqr)f is about F distribution. The result obtained from these functions give the same result than The F Fisher-Snedecor in cephes lib (from http://www.moshier.net/). IIs it the same F (I think) and what's the difference between the two F. Cheers, Greg -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 513 bytes Desc: not available Url : https://www.stat.math.ethz.ch/pipermail/r-devel/attachments/20030613/46f45861/smime.bin