Inline below. Bert Gunter Genentech Nonclinical Biostatisics
-----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Steve Lianoglou Sent: Tuesday, August 18, 2009 8:07 AM To: Ajay Singh Cc: r-help@r-project.org Subject: Re: [R] value of nth percentile Hi Ajay, On Aug 18, 2009, at 8:16 AM, Ajay Singh wrote: > Dear All, > I have to get the value of say 90th percentile of precipitation time > series.. The series is of daily precipitation value of 96 years, I > have to to get 90the percentile value of daily precipitation each > year. If you know the R code or command for this please let me know. > I would appreciate your early response. R> dat <- rnorm(100, mean=10, sd=2) R> quantile(dat, .9) 90% 12.53047 R> sum(dat < quantile(dat, .9)) / length(dat) [1] 0.9 -steve -- Neither of these statements is (strictly) correct. ?quantile will explain that different algorithms can be used and will give different results: > dat <- 1:10 > quantile(dat,.8) 80% 8.2 > quantile(dat,.8,type=9) 80% 8.575 > quantile(dat,.8,type=4) 80% 8 > sum(dat < quantile(dat,.8,type=9))/10 [1] 0.8 > sum(dat < quantile(dat,.8,type=4))/10 [1] 0.7 -- Steve Lianoglou Graduate Student: Computational Systems Biology | Memorial Sloan-Kettering Cancer Center | Weill Medical College of Cornell University Contact Info: http://cbio.mskcc.org/~lianos/contact ______________________________________________ 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.