Hello, I want to fit a tree parameter distribution to given data. I tried it with sample data using the "fitdistr" function. Here my workflow that didn't had any result: I started with the generalized gamma distr, which is: r*dgamma(x^r,shape,rate) The R-function is: ggamma = function (x,r,shape,rate) r*dgamma(x^r,shape,rate=rate) For the first step I assumed r = 1 and I generated random numbers with the "standard" Gamma distr. rn=rgamma(1000,10,5) In the last step I want to reconstruct the parameters from the dataset: library(MASS) fitdistr(rn, ggamma, list(r=1,shape=10,rate=5)) But there is an error: Error in fitdistr(rn, ggamma, list(r = 1, shape = 10, rate = 5)) : optimization failed although I should have a nearly model-made dataset. Where is the problem and how could it be solved? Carsten
[[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html