On 10/12/2007 1:16 PM, D. R. Evans wrote: > The standard chisq.test() and fisher.test() functions, when applied to > two distributions (to determine whether the same underlying > distribution applies to both) requires one to pre-bin the > distributions. > > Is there a library function (either built-in or in a package) that > acts more like the ks.test() function, in that one can simply pass the > two distributions and have it do the necessary binning as well as the > actual statistical test? > > (Yes, you can accuse me of laziness: I just don't fancy trying to > figure out a routine that would make sure that there more than 5 > samples in each of the expected bins before applying the chi-squared > test. It seems too much like re-inventing an elementary wheel that > must have been invented by someone else.)
If you have a quantile function q() for the distribution, a sample size of N, and want expected counts of 5 in each bin, just calculate the cutpoints as nbins <- floor(N/5) cutpoints <- c(-Inf, q( (1:(nbins-1)/nbins)), Inf) Duncan Murdoch ______________________________________________ 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.
