First, why doesn't the following code work? What exactly is the error you are getting?
par(mfrow=c(1,2)) pop1<-rnorm(100) hist(pop1,freq=F,ylim=c(0,1)) pop2<-rgamma(100,1,1) hist(pop2,freq=F,ylim=c(0,1)) Second, help.search("multihist") returned the multi.hist function. Is multi.hist [instead of multihist] the function you are working with? Third, it sounds like you want to change the scale of the y axis. The scale change you want is linear, so why not change the scale manually? Something like this will manually change the scale to percentages: pop1<-rnorm(156) hist.pop1<-hist(pop1,yaxt="n",ylab="%",main="") t<-axTicks(2) axis(2,at=t,labels=round(t/length(pop1)*100,1)) Then, again, changing the scale creates more of a bar chart than a histogram plot. Maybe you want to look at the barchart functions directly. Or maybe directly calculate the bin percentages and plot them directly. I think you have a lot of options to plot what you want. -tgs On Fri, May 14, 2010 at 11:51 AM, Federico Calboli <f.calb...@imperial.ac.uk > wrote: > On 14 May 2010, at 16:09, Thomas Stewart wrote: > > > Please be more specific with your question. Perhaps a simple subset of > the data you are trying to plot? Here is some non-specific advice: > > > > Plotting histograms as percentages instead of frequency counts is already > an option of the hist function. For example, > > > > pop1<-rnorm(100) > > hist(pop1,freq=F) > > What you get is a desity, not a percentage, so you could have two bars with > a value greater 0.5 on the y-axis. The fact that the area sums up to 1 does > not mean that the sum of the heights adds up to 1 --the thing that my > ignoramus want to see to understand. On the other hand, freq =T gives the > counts, and the sum of the counts is the population total -- therefore (bar > counts)/(pop total) *100 is the precentage. If I could slap that on the > label of the y-axis I'd be sorted. > > > > > If you are plotting two histograms side-by-side (on the percentage > scale), the y-axis of both plots can be set with the ylim option. For > example, > > > > par(mfrow=c(1,2)) > > pop1<-rnorm(100) > > hist(pop1,freq=F,ylim=c(0,1)) > > pop2<-rgamma(100,1,1) > > hist(pop2,freq=F,ylim=c(0,1)) > > I'm using multhist(). The above would not work for me. > > F > > > > > > > > If your question were clearer, I might be able to help in more specific > ways. > > > > -tgs > > > > On Fri, May 14, 2010 at 10:19 AM, Federico Calboli < > f.calb...@imperial.ac.uk> wrote: > > Hi All, > > > > I am in the annoying position of having to present some data to someone > who seems to be somewhat less than numerate. I need to label the y-axes of a > multhist with the y-axis labeled not as counts but as percentage of a > population. Plotting the standard histogram is in a way fine, all I need is > to: > > > > -- have a left-handside y-axis labels for pop 1 and a right-handside > y-axis labels for pop2 > > -- replace the counts in each axis with population percentages (easy to > calculate, but how to stick them there?) > > > > Any suggestion would be gratefully received. > > > > F > > > > > > -- > > Federico C. F. Calboli > > Department of Epidemiology and Biostatistics > > Imperial College, St. Mary's Campus > > Norfolk Place, London W2 1PG > > > > Tel +44 (0)20 75941602 Fax +44 (0)20 75943193 > > > > f.calboli [.a.t] imperial.ac.uk > > f.calboli [.a.t] gmail.com > > > > ______________________________________________ > > 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. > > > > -- > Federico C. F. Calboli > Department of Epidemiology and Biostatistics > Imperial College, St. Mary's Campus > Norfolk Place, London W2 1PG > > Tel +44 (0)20 75941602 Fax +44 (0)20 75943193 > > f.calboli [.a.t] imperial.ac.uk > f.calboli [.a.t] gmail.com > > > > > > > [[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.