number point under-flow

-----Original Message-----
From: Roger D. Peng [mailto:rpeng at jhsph.edu]
Sent: 04 February 2004 14:49
To: Muller, Arne PH/FR
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] number point under-flow


Did you compile with gcc-2.96?  I think there were some 
problems with the floating point arithmetic with that 
compiler (at least for the earlier versions released by Red 
Hat).

-roger

Arne.Muller at aventis.com wrote:

Hello,

I've come across the following situation in R-1.8.1 

(compile + running under

RedHat 7.1):

phyper(24, 514, 5961-514, 53, lower.tail=T)

[1] 1

phyper(24, 514, 5961-514, 53, lower.tail=F)

[1] -1.037310e-11

I'd expect the later to be 0 or some very small positive 

number. Is this a

number under-flow of the calculation? Do you think I'm safe 

if I just set the

result to 0 in these cases?

	kind regards,

	Arne