On Fri, May 15, 2009 at 6:22 AM, lagreene <lagreene...@gmail.com> wrote: > > Thanks Jorge, > > but I still don't understand where they come from. when I use: > fitdistr(mydata, "t", df = 9) and get values for m and s, and the variance > of my data should be the df/s? > > I jsut want to be able to confirm how m and s are calculated
I've wondered the same kind of thing and I've learned the answer is easy! It is not so easy for all R functions, but did you try this with fitdistr? > library (MASS) > fitdistr the output that follows is the ACTUAL FORMULA that is used to make the calculations! I've not yet mastered the art of getting code for some functions. > predict function (object, ...) UseMethod("predict") <environment: namespace:stats> But I know there is a way to get that code if you know the correct way to run getS3method(). But I usually just go read the R source code rather than puzzle over that. > > mydt <- function(x, m, s, df) dt((x-m)/s, df)/s > fitdistr(x2, mydt, list(m = 0, s = 1), df = 9, lower = c(-Inf, 0)) > > Thanks anyway for the help! -- Paul E. Johnson Professor, Political Science 1541 Lilac Lane, Room 504 University of Kansas ______________________________________________ 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.