Re: [R] R- exp(-1000) ? - how to get R to give me an actual answer ?
At 03:42 PM 26/10/2005, you wrote: >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 Or in Axiom, which is open source too: numeric exp(-1000) 0.50759588975494567653E-434 Type: Float >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 __ 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
Re: [R] R- exp(-1000) ? - how to get R to give me an actual answer ?
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
[R] R- exp(-1000) ? - how to get R to give me an actual answer ?
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
