Is there any way to increase the decimal accuracy for probability distributions. For example (in R):> 1-pchisq(90,5)[1] 0 But in Maple, I find that the value is 0.67193x10-17. I need to compare some really small p-values...is there a way to increase the decimal place accuracy beyond 1x10-16 (which seems to be the limit)? Any help would be appreciated. Ann
Ann Hess wrote:> Is there any way to increase the decimal accuracy for probability > distributions. For example (in R): > >> 1-pchisq(90,5) > [1] 0 > > But in Maple, I find that the value is 0.67193x10-17.Look at this: > 1-pchisq(90,5) [1] 0 > pchisq(90,5, lower=FALSE) [1] 6.71932e-18 Kjetil> > I need to compare some really small p-values...is there a way to increase > the decimal place accuracy beyond 1x10-16 (which seems to be the limit)? > > Any help would be appreciated. > > Ann > > ______________________________________________ > R-help at 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 >
Ann Hess wrote:> Is there any way to increase the decimal accuracy for probability > distributions. For example (in R): > > >>1-pchisq(90,5) > > [1] 0 > > But in Maple, I find that the value is 0.67193x10-17. > > I need to compare some really small p-values...is there a way to increase > the decimal place accuracy beyond 1x10-16 (which seems to be the limit)? > > Any help would be appreciated. > > Ann >Try pchisq(90, 5, lower.tail = FALSE) Also read FAQ 7.31. http://cran.r-project.org/faqs.html HTH, --sundar