Hi Martin, No, I get frequencies greather than 1.
See the code: #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, freq=FALSE) #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") Thanks anyway Best Jº From: Martyn Byng [via R] [mailto:ml-node+3333757-242386738-215...@n4.nabble.com] Sent: quinta-feira, 3 de Março de 2011 17:12 To: jpmaroco Subject: Re: Probabilities greather than 1 in HIST Hi, Does xx = rnorm(100) hist(xx,freq=FALSE) curve(dnorm,add=TRUE) give you what you want? Martyn -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of David Winsemius Sent: 03 March 2011 17:00 To: jpmaroco Cc: [hidden email] Subject: Re: [R] Probabilities greather than 1 in HIST On Mar 3, 2011, at 10:29 AM, jpmaroco wrote: > 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. In my earlier reply I meant to type yaxt="n". -- David. > > Best, > > Joao > > > > From: David Winsemius [via R] [mailto:[hidden email] > ] > 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> >> >> >> <http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333388.html?by-user=t >> >> <http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333388.html?by-user=t&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 > > <http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333619.html?by-user=t> > > > To unsubscribe from Probabilities greather than 1 in HIST, click > here > <http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code > > <http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=3333388&code=anBtYXJvY29AZ21haWwuY29tfDMzMzMzODh8LTE1ODEwNTQwMA==&by-user=t> > &node=3333388&code=anBtYXJvY29AZ21haWwuY29tfDMzMzMzODh8LTE1ODEwNTQwMA== > > . > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333670.html > > <http://r.789695.n4.nabble.com/Probabilities-greather-than-1-in-HIST-tp3333388p3333670.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. ________________________________________________________________________ This e-mail has been scanned for all viruses by Star.\ _...{{dropped:12}} ______________________________________________ [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-tp3333388p3333757.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-tp3333388p3334067.html Sent from the R help mailing list archive at Nabble.com. 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