It's here (search the sources for the appropriately named qbeta.c) but I can't guarantee you'll understand it easily: Martin Maechler (and others) works hard to make these the best in the business, but that performance comes at a price, here paid in opacity:
http://svn.r-project.org/R/trunk/src/nmath/qbeta.c Michael On Fri, Mar 9, 2012 at 3:08 PM, Anamika Chaudhuri <canam...@gmail.com> wrote: > Hi David: > > Thanks, I actually realized it was error on my part. I didnt think there > was a problem with R-code, just wanted to get a better understanding of the > function qbeta. > > Anamika > > On Fri, Mar 9, 2012 at 3:04 PM, David Winsemius <dwinsem...@comcast.net>wrote: > >> >> On Mar 9, 2012, at 2:48 PM, Anamika Chaudhuri wrote: >> >> HI All: >>> >>> Does anyone know the code behind the qbeta function in R? >>> >> >> Well, yes, but don't you think it would be wise to question whether your >> code might be the problem rather than the R code? >> >> >> I am using it to calculate exact confidence intervals and I am getting >>> 'NaN' at places I shouldnt be. Heres the simple code I am using: >>> >>> k<-3 >>> >>>> x<-NULL >>>> p<-rbeta(k,3,3)# so that the mean nausea rate is alpha/(alpha+beta) >>>> min<-10 >>>> max<-60 >>>> n<-as.integer(runif(3,min,max)**) >>>> for(i in 1:k) >>>> >>> + x<-cbind(x,rbinom(5,n[i],p[i])**) >>> >> >> Isn't this going to make x get longer with each pass through the loop? I >> think your parameter are then going to be interpreted as values of "x". >> Looks like "user error" to me. >> >> -- >> David >> >> >> >>>> # Exact Confidence Interval >>>> >>>> l_cl_exact<-qbeta(.025, x, n-x+1) >>>> >>> Warning message: >>> In qbeta(p, shape1, shape2, lower.tail, log.p) : NaNs produced >>> >>>> u_cl_exact<-qbeta(.975, x+1, n-x) >>>> >>> Warning message: >>> In qbeta(p, shape1, shape2, lower.tail, log.p) : NaNs produced >>> >>>> x >>>> >>> [,1] [,2] [,3] >>> [1,] 8 12 14 >>> [2,] 5 15 13 >>> [3,] 5 12 12 >>> [4,] 8 21 12 >>> [5,] 8 14 12 >>> >>>> n >>>> >>> [1] 10 36 31 >>> >>>> l_cl_exact >>>> >>> [,1] [,2] [,3] >>> [1,] 0.44390454 0.2184996 0.2314244 >>> [2,] 0.04667766 NaN 0.2454760 >>> [3,] 0.05452433 0.1855618 NaN >>> [4,] 0.44390454 0.4862702 0.1855618 >>> [5,] 0.10115053 NaN 0.2184996 >>> >>> Thanks for your help. >>> Anamika >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________**________________ >>> R-help@r-project.org mailing list >>> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> >>> PLEASE do read the posting guide http://www.R-project.org/** >>> posting-guide.html <http://www.R-project.org/posting-guide.html> >>> and provide commented, minimal, self-contained, reproducible code. >>> >> >> David Winsemius, MD >> West Hartford, CT >> >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
