On Mar 13, 2010, at 3:39 PM, Tal Galili wrote:
Hi all, A friend send me a question on why does this: x<-rpois(100,1) sum( hist(x)$density ) Gives out "2"
Yes. And... > hist(x)$breaks [1] 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
I tried this: sum( hist(x, freq =T)$density ) It didn't help. Then he came back with the following insight: # with breaks b<-c(0,0.9,1:8) sum(hist(x,breaks=b)$density) # Much more then 2 # but if we add weights according to the interval length sum(hist(x,breaks=b)$density * diff(b)) # it works What do you think ?
I do think that neither you nor your friend understand densities. -- David. David Winsemius, MD West Hartford, CT ______________________________________________ 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.
