On 25/08/16 23:28, Marine Regis wrote:
Hello,I used the function "mix" (package "mixdist'') to fit Gamma mixture distributions. The function gives mu and sigma parameters (output below). How can I find the scale and shape parameters of the Gamma distributions ? Parameters: pi mu sigma 1 0.2089 185.7 285.4 2 0.7911 530.1 423.5
I have no familiarity with the "mixdist" package, but I find it very surprising that mix() would return a fit of a Gamma mixture parametrised in terms of mu and sigma. I suspect that you are doing something wrong.
If it really *does* give you such a parametrisation, you can recover the shape (alpha) and scale (beta) parameters by solving
mu = alpha*beta sigma^2 = alpha*beta^2 for alpha and beta. cheers, Rolf Turner -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276 ______________________________________________ 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.
