Hi all, I have a problem on how R calculates Percentiles : Suppose I have following data set:> data1[1] -16648185 -14463457 -14449400 -13905309 -13443436 -13234755 -12956282 -11660896 [9] -10061040 -9805005 -9789583 -9754642 -9562164 -9391709 -9212182 -9151073 [17] -9092732 -9068214 -8978151 -8943912 -8761890 -8632106 -8541580 -8501249 [25] -8234466 -8219015 -8193543 -7488279 -7340768 -7236684 -7225458 -7159465 [33] -6819625 -6810858 -6755620 -6626439 -6610901 -6551762 -6207377 -6192583 [41] -6106783 -6077051 -6035300 -6035195 -6019017 -5954375 -5946285 -5886082 [49] -5880402 -5723368 -5668698 -5599168 -5548276 -5445734 -5412312 -5384707 [57] -5309365 -5303425 -5285274 -5204585 -5096301 -5092182 -5053349 -5041533 [65] -5021234 -5005402 -4984232 -4981990 -4964457 -4936653 -4920384 -4918021 [73] -4895351 -4843258 -4824730 -4774792 -4771018 -4616156 -4590430 -4444262 [81] -4443954 -4435397 -4415112 -4374465 -4341858 -4267891 -4252410 -4185021 [89] -4164458 -4158863 -4020436 -4006030 -3975819 -3959667 -3916414 -3876878 [97] -3765340 -3729338 -3713670 -3634991 Now the 5th percentile should be value corresponding to 0.05*(100+1) = 5.05 = 5 (rounded) hence : -13443436 But R give the value :> quantile(data1, 0.05)5% -13245189 Can anyone clarify me on this regards? Thanks Megh ____________________________________________________________________________________ Comedy with an Edge to see what's on, when. [[alternative HTML version deleted]]
Quantiles aren't uniquely defined. Type ?quantile to learn more about the various possibilities built in to R. Ted. Megh Dal wrote on 06/18/2007 04:37 PM:> Hi all, > > I have a problem on how R calculates Percentiles : > > Suppose I have following data set: > >> data1 >> > [1] -16648185 -14463457 -14449400 -13905309 -13443436 -13234755 -12956282 -11660896 > [9] -10061040 -9805005 -9789583 -9754642 -9562164 -9391709 -9212182 -9151073 > [17] -9092732 -9068214 -8978151 -8943912 -8761890 -8632106 -8541580 -8501249 > [25] -8234466 -8219015 -8193543 -7488279 -7340768 -7236684 -7225458 -7159465 > [33] -6819625 -6810858 -6755620 -6626439 -6610901 -6551762 -6207377 -6192583 > [41] -6106783 -6077051 -6035300 -6035195 -6019017 -5954375 -5946285 -5886082 > [49] -5880402 -5723368 -5668698 -5599168 -5548276 -5445734 -5412312 -5384707 > [57] -5309365 -5303425 -5285274 -5204585 -5096301 -5092182 -5053349 -5041533 > [65] -5021234 -5005402 -4984232 -4981990 -4964457 -4936653 -4920384 -4918021 > [73] -4895351 -4843258 -4824730 -4774792 -4771018 -4616156 -4590430 -4444262 > [81] -4443954 -4435397 -4415112 -4374465 -4341858 -4267891 -4252410 -4185021 > [89] -4164458 -4158863 -4020436 -4006030 -3975819 -3959667 -3916414 -3876878 > [97] -3765340 -3729338 -3713670 -3634991 > > Now the 5th percentile should be value corresponding to 0.05*(100+1) = 5.05 = 5 (rounded) > > hence : -13443436 > > But R give the value : > >> quantile(data1, 0.05) >> > 5% > -13245189 > > Can anyone clarify me on this regards? > > Thanks > Megh > > > > ____________________________________________________________________________________ > > Comedy with an Edge to see what's on, when. > > [[alternative HTML version deleted]] > > ______________________________________________ > 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 > and provide commented, minimal, self-contained, reproducible code. >-- Dr E.A. Catchpole Visiting Fellow Univ of New South Wales at ADFA, Canberra, Australia _ and University of Kent, Canterbury, England 'v' - www.pems.adfa.edu.au/~ecatchpole / \ - fax: +61 2 6268 8786 m m - ph: +61 2 6268 8895
On Sun, 17 Jun 2007, Megh Dal wrote:> Hi all, > > I have a problem on how R calculates Percentiles : > > Suppose I have following data set: >> data1 > [1] -16648185 -14463457 -14449400 -13905309 -13443436 -13234755 -12956282 -11660896 > [9] -10061040 -9805005 -9789583 -9754642 -9562164 -9391709 -9212182 -9151073 > [17] -9092732 -9068214 -8978151 -8943912 -8761890 -8632106 -8541580 -8501249 > [25] -8234466 -8219015 -8193543 -7488279 -7340768 -7236684 -7225458 -7159465 > [33] -6819625 -6810858 -6755620 -6626439 -6610901 -6551762 -6207377 -6192583 > [41] -6106783 -6077051 -6035300 -6035195 -6019017 -5954375 -5946285 -5886082 > [49] -5880402 -5723368 -5668698 -5599168 -5548276 -5445734 -5412312 -5384707 > [57] -5309365 -5303425 -5285274 -5204585 -5096301 -5092182 -5053349 -5041533 > [65] -5021234 -5005402 -4984232 -4981990 -4964457 -4936653 -4920384 -4918021 > [73] -4895351 -4843258 -4824730 -4774792 -4771018 -4616156 -4590430 -4444262 > [81] -4443954 -4435397 -4415112 -4374465 -4341858 -4267891 -4252410 -4185021 > [89] -4164458 -4158863 -4020436 -4006030 -3975819 -3959667 -3916414 -3876878 > [97] -3765340 -3729338 -3713670 -3634991 > > Now the 5th percentile should be value corresponding to 0.05*(100+1) = > 5.05 = 5 (rounded)According to you, but not according to ?quantile, which gives you a choice of 9 definitions, yours not being the default.> hence : -13443436 > > But R give the value : >> quantile(data1, 0.05) > 5% > -13245189 > > Can anyone clarify me on this regards? > > Thanks > Megh > > > [[alternative HTML version deleted]] > > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.htmlPLEASE do as we ask. -- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595