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graphs of gamma, normal fit to a histogram are about half as large as they should be

Benjamin Caldwell 
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?

Thanks

*Ben Caldwell*

PhD Candidate
University of California, Berkeley

Thread (5 messages)

Benjamin Caldwell graphs of gamma, normal fit to a histogram are about half as large as they should be May 13 Rolf Turner graphs of gamma, normal fit to a histogram are about half as large as they should be May 13 Benjamin Caldwell graphs of gamma, normal fit to a histogram are about half as large as they should be May 15 Rolf Turner graphs of gamma, normal fit to a histogram are about half as large as they should be May 15 Benjamin Caldwell graphs of gamma, normal fit to a histogram are about half as large as they should be May 17