> fitdistr(y, "chi-squared", start = list(4), method = "Brent", lower=0.9, > upper=3)
First, it would be nice if your mail had a subject line and you showed the error message you got from this command. I got: > z <- fitdistr(y, "chi-squared", start = list(4), method="Brent", lower=0.9, upper=3) > z Error in dn[[2L]] : subscript out of bounds > str(z) List of 5 $ estimate: num 1 $ sd : num 0.00286 $ vcov : num [1, 1] 8.16e-06 $ loglik : num -79007 $ n : int 100000 - attr(*, "class")= chr "fitdistr" showing that the error was in the printing of the result, not in computing the result. There are a few problems here. First, the print method assumes that the optimizer attaches parameter names to the parameter vector. Second, optim(method="Brent") does not attach a name to its output parameter the way the other optimization method do (I suppose that is because it only works on univariate problems.) Third, you didn't supply a parameter name in 'start'. You can get a printable answer by using the default method and supplying a name for the parameter. > zz <- fitdistr(y, "chi-squared", start = list(df=4), lower=0.9, upper=3) > zz df 1.003840114 (0.002856363) > str(zz) List of 5 $ estimate: Named num 1 ..- attr(*, "names")= chr "df" $ sd : Named num 0.00286 ..- attr(*, "names")= chr "df" $ vcov : num [1, 1] 8.16e-06 ..- attr(*, "dimnames")=List of 2 .. ..$ : chr "df" .. ..$ : chr "df" $ loglik : num -79007 $ n : int 100000 - attr(*, "class")= chr "fitdistr" By the way, giving a starting value that is not between the upper and lower limits that you also gave is asking for trouble of a different sort. Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Jim Silverton > Sent: Tuesday, November 19, 2013 4:30 PM > To: r-help@r-project.org > Subject: [R] (no subject) > > I generated some random data using R and then trying to see if it came from > the same distribution but the erros keep piling. Can anyone help? > > > > y=rchisq(100000,1) > mean(y) > var(y) > library(MASS) > fitdistr(y, "chi-squared", start = list(4), method = "Brent", lower=0.9, > upper=3) > > > -- > Thanks, > Jim. > > [[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. ______________________________________________ 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.