Pick the mean (mu) and variance (sig2) you want. Then, shape = mu^2/sig2 and scale = sig2/mu. This should work fine if your mean is large enough so that p(x = 0 or 1) is small.
-- View this message in context: http://r.789695.n4.nabble.com/Gamma-count-tp4711845p4711853.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.