Read the help page for the quantile function (the whole page, there is a lot of good detail in there), the 2nd reference on the page should also be a helpful read.
-- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of ANJAN PURKAYASTHA > Sent: Thursday, January 22, 2009 9:52 AM > To: r-help@r-project.org > Subject: [R] quantile question > > Hi, > A simple quantile question: > I need to calculate the 95% and 5% quantiles (aka percentiles) for the > following data: > 67.12 > 64.51 > 62.06 > 55.45 > 51.41 > 43.78 > 10.74 > 10.14 > > if I use the formula: 95% quantile point= 95 (8+1)/100, I get the > 8.55th > point as the 95% quantile. Which does not make too much sense as I have > only > 8 data points. > The other option is to use (95*8)/100 = 7.6th data point (which can be > found > by interpolation between the 7th and 8th data points). > Reportedly, the second formula is not too accurate. However in my case > the > first formula does not make much sense. > > Any advice? > > TIA, > Anjan > > -- > ============================= > anjan purkayastha, phd > bioinformatics analyst > whitehead institute for biomedical research > nine cambridge center > cambridge, ma 02142 > > purkayas [at] wi [dot] mit [dot] edu > 703.740.6939 > > [[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.