David Winsemius <[EMAIL PROTECTED]> wrote in news:[EMAIL PROTECTED]:
> "tom soyer" <[EMAIL PROTECTED]> wrote in > news:[EMAIL PROTECTED]: > >> John, >> >> The Excel's percentrank function works like this: if one has a number, >> x for example, and one wants to know the percentile of this number in >> a given data set, dataset, one would type =percentrank(dataset,x) in >> Excel to calculate the percentile. So for example, if the data set is >> c(1:10), and one wants to know the percentile of 2.5 in the data set, >> then using the percentrank function one would get 0.166, i.e., 2.5 is >> in the 16.6th percentile. >> >> I am not sure how to program this function in R. I couldn't find it as >> a built-in function in R either. It seems to be an obvious choice for >> a built-in function. I am very surprised, but maybe we both missed it. > > My nomination for a function with a similar result would be ecdf(), the > empirical cumulative distribution function. It is of class "function" so > efforts to index ecdf(.)[.] failed for me. > >> df4$V2 > [1] 1 1 1 1 1 5 6 7 9 #copied wrong line in R session Make that; df4$V2<-c(1,1,3,3,4,5,6,7,10,9) [1] 1 1 3 3 5 6 7 9 >> ecdf.V2<-ecdf(df4$V2) >> ecdf.V2(df4$V2) > [1] 0.2 0.2 0.4 0.4 0.5 0.6 0.7 0.8 1.0 0.9 > > Don't have Excel, but the OpenOffice.org Calc program has the same > function. It produces: > x percentrank(x) > 1 0.0000000 > 1 0.0000000 > 3 0.2222222 > 3 0.2222222 > 4 0.4444444 > 5 0.5555556 > 6 0.6666667 > 7 0.7777778 > 10 1.0000000 > 9 0.8888889 > > (Not that I am saying that the OO.o/Excel function is what one _should_ > want. Its behavior seems pathological to me.) > ______________________________________________ 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.
