Dear David, Thanks for your prompt reply.
I see your point. But how can I get a histogram with relative frequencies? If I use >plot(xhist,yhist) I get absolute frequencies in the Y axis. Best, Joao From: David Winsemius [via R] [mailto:ml-node+3333619-1272092771-215...@n4.nabble.com] Sent: quinta-feira, 3 de Março de 2011 16:01 To: jpmaroco Subject: Re: Probabilities greather than 1 in HIST On Mar 3, 2011, at 8:03 AM, jpmaroco wrote: > Dear all, > I am a newbie in R and could not find help on this problem. I am > trying to > plot an histogram with probabilities in the y axis. This is the code > I am > using: > > #TLC uniform > n=30 > mi=1; mx=6 > nrep=1000 > xbar=rep(0,nrep) > for (i in 1:nrep) {xbar[i]=mean(runif(n,min=mi,max=mx))} > hist(xbar,prob=TRUE,breaks="Sturges",xlim=c(1,6),main=paste("n =",n), > xlab="Média", ylab="Probabilidade") > curve(dnorm(x,mean=mean(xbar),sd=sd(xbar)),add=TRUE,lwd=2,col="red") > > The problem is that I am getting greater than 1 probabilities in the > Y axis? > Is there a way to correct this? Despite the argument name, which I agree suggests that probabilities will be plotted, what is really described in the help page is that densities will be plotted, and densities may be greater than 1. You can suppress plotting of the y-axis, calculate the probabilities for each of the groups returned by hist, and then use the axes function. > xhist <- hist(xbar,breaks="Sturges",plot=FALSE) > yhist <- xhist$counts/sum(xhist$counts) > yhist [1] 0.002 0.027 0.087 0.236 0.287 0.228 0.107 0.021 0.004 0.001 > Many thanks in advance. > Joao > > -- > View this message in context: > http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333388.html > > <http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333388.html?by-user=t> > > Sent from the R help mailing list archive at Nabble.com. > [[alternative HTML version deleted]] > > ______________________________________________ > [hidden email] 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. David Winsemius, MD Heritage Laboratories West Hartford, CT ______________________________________________ [hidden email] 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. _____ If you reply to this email, your message will be added to the discussion below: http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333619.html To unsubscribe from Probabilities greather than 1 in HIST, click here <http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=3333388&code=anBtYXJvY29AZ21haWwuY29tfDMzMzMzODh8LTE1ODEwNTQwMA==> . -- View this message in context: http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333670.html Sent from the R help mailing list archive at Nabble.com. [[alternative HTML version deleted]]
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