On Apr 16, 2013, at 20:12, Janh Anni <annij...@gmail.com> wrote:
> Hello All, > > Would anyone be able to help me understand how R computes a > quantile-quantile plot for comparing two data samples with unequal sample > sizes? Normally, the procedure should be to rearrange the larger data > sample into n equally-spaced parts using interpolation, where n is the > sample size of the smaller sample, and then plot the matching data pairs. I > tried using different plotting position formulas for the interpolation but > cannot reproduce what R is plotting. Thanks in advance. If you type qqplot at the prompt you'll be given the code and can review it for yourself. It's also available online for your viewing pleasure. http://svn.r-project.org/R/trunk/src/library/stats/R/qqplot.R It seems the key is the approx (linear interpolation) function, but you can work out the details. Michael > > Regards > Janh > > [[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. [[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.
