[R] number point under-flow

Arne.Muller@aventis.com Arne.Muller at aventis.com
Wed Feb 4 14:53:11 CET 2004


Hi,

yes, I did compile it with gcc 2.96 ... . Do you've an estimate on how "bad"
this error is, e.g. how much it effects the calculations in R?

	kind regards,
	
	Arne

> -----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
> > 
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>




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