In your example it appears that you are plotting a histogram (on the frequency scale) and then superimposing scalar multiples of gamma and Gaussian densities.
You should just plot a histogram (with frequency=FALSE) and then superimpose the densities --- without any scalar multipliers. If that doesn't work, please provide a minimal *reproducible* (no one but you has the ``rwb'' data object) example of the problem that you are having (as the posting guide requests). cheers, Rolf Turner On 16/05/11 17:01, Benjamin Caldwell wrote: > Hmm; still missing something - hist defaults to frequencies, not prob. > densities; and, I thought I'd scaled the fitted lines to the values in > the data frame. Just going with it, I specified freq=FALSE, and the > prob density was of course at a different order of magnitude than the > lines. > > What are you trying to hint at? > > > On Fri, May 13, 2011 at 6:05 PM, Rolf Turner <rolf.tur...@xtra.co.nz > <mailto:rolf.tur...@xtra.co.nz>> wrote: > > On 14/05/11 10:00, Benjamin Caldwell wrote: > > Hello, > > I'm trying to compare the fit of two distributions, normal and > gamma, to a > histogram of my response variable. > > > rate<-mean(na.omit(rwb$post.f.crwn.length))/var(na.omit(rwb$post.f.crwn.length)) > shape<-rate*mean(na.omit(rwb$post.f.crwn.length)) > hist((rwb$post.f.crwn.length), main="rwb$post.f.crwn.length") > > lines(seq(0.01,70,0.01),length(rwb$post.f.crwn.length)*dgamma(seq(0.01,70,0.01),shape,rate)) > > lines(seq(0,70,0.1),length(na.omit(rwb$post.f.crwn.length))*dnorm(seq(0,70,.1),mean(na.omit(rwb$post.f.crwn.length)),sqrt(var(na.omit(rwb$post.f.crwn.length)))) > > However, the height of the two curves are about 1/3 to 1/4 the > height that > they should be compared to the histogram. Any ideas? > > > Yes. Read the help on "hist"! (Hint: Pay particular attention > to the > "freq" and/or "probability" arguments.) > > cheers, > > Rolf Turner > > [[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.