Since log base 10 is log(x)/log(10) the exponent is:
floor(log(exp(-1000))/log(10))
= floor(-1000/log(10))
which in an R session gives:
> floor(-1000/log(10))
[1] -435
and the mantissa is:
exp(-1000)/10^(-435)
= exp(-1000)/exp(-435*log(10))
= exp(-1000+435*log(10))
which in an R session gives:
> exp(-1000+435*log(10))
[1] 5.075959
Thus the answer is 5.075959e-435 though, of course,
we can't represent that directly on your computer.
We can double check this with yacas which is a free
computer algebra system that supports arbitrary
precision math:
In> N(Exp(-1000))
Out> 0.5075958898e-434
On 10/26/05, rramacha <[EMAIL PROTECTED]> wrote:
> Dear All,
>
> I am a novice user of the R software package. When I try and compute,
> exp(-1000) or exp(-2000), i get the answer as zero. Is there any way i can get
> R to compute the answer and give me an actual number ? ( by increasing the
> precision or any other method).
>
> If I cannot get R to give me a number, can anybody give me some advice on how
> to manually compute this number ?
>
> I would greatly appreciate your help on this issue.
>
> Thanks
> Ravi
>
> Ravichandran "Ravi" Ramachandran
>
> Graduate Teaching Assistant
> Department of Statistics
> The University of Tennessee,Knoxville
> USA
> E-mail : [EMAIL PROTECTED]
> Phone : Official - 865 - 974 - 2739 (Aconda Court)
> Residence - 865 - 946 - 5155
> Webpage : http://web.utk.edu/~rramacha
>
>
> " Space maybe the final frontier
> But its made in a Hollywood basement
> - The Red Hot Chilli Peppers - 'Californication'
>
> Space maybe the final frontier
> But it can be 'replicated' in a Hollywood basement
> - Me, after taking the Stat 573 class
> "
>
>
> "Thank God every day when you get up that you have something to do that day
> which must be done whether you like it or not. Being forced to work and
> forced to do your best will breed in you temperance and self-control,
> diligence and strength of will"
> - Basil Carpenter
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>
______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
