It is not the case as you described. In any case, the total area should be 1 and labeled fraction on y axis should be far less than 1, since I have more than 10000 data points. I also test differerent bin size by change the break.
I draw the graph using only 1 group, the same result was obtained. Any othe suggestion? Charles. Greg Snow-2 wrote: > > When freq=FALSE then the y axis is not the proportion in each group (what > I am assuming you mean by fraction), but rather is scaled so that the > total area of the histogram is 1 (making comparing to theoretical > densities easier). If all the data values are between 0 and 1, then the > height of at least one bar needs to be >= 1 for the total area to equal 1. > > If you want the y-axis to show relative frequency (proportion, fraction, > etc.), then you either need to plot the y-axis yourself or use a different > function than 'hist'. > > -- > Gregory (Greg) L. Snow Ph.D. > Statistical Data Center > Intermountain Healthcare > greg.s...@imail.org > 801.408.8111 > > >> -----Original Message----- >> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- >> project.org] On Behalf Of charles78 >> Sent: Monday, June 22, 2009 10:08 AM >> To: r-help@r-project.org >> Subject: [R] Help needed: Fraction for Histogram > 1 ??? >> >> >> I have been trying to draw histogram for my manscript and found some >> strange >> things that I could not figure out why. >> >> Using the same code listed below I have successfully draw histograms >> for a >> few figures with fraction labeled on Y axis less than 1 (acturally >> between 0 >> to 0.1). But one dataset gives the Y axis label 0 to 5 as fraction. >> This >> is not true, as fraction are less than 1, although the value >> distribution on >> the figure seems to me is right. >> >> The only difference between the first few datasets and last dataset is: >> >> All values for the first few data sets > 1. >> >> The values for the last data sets between 0 and <1. >> >> Any idea why this happens. >> >> Your help is highly appreciated. >> >> Charles >> >> =================================================== >> postscript("Figure.eps", paper="letter", horizontal=FALSE) >> par(mfrow=c(3,3)) >> par(omi=c(2,0.2,1.8,0.2), mai=c(0.4, 0.4, 0.5, 0.1) ) >> >> my.input <- read.table("input.data", header=FALSE, sep="\t") >> my.input.exp <- read.table("exp.data", header=FALSE, sep="\t") >> >> hist(my.input.exp[,2], breaks=40,freq = FALSE,xlab="", border = >> "grey30", >> ylab="", main="") >> hist(my.input[,2], breaks=40,freq = FALSE,xlab="", ylab="", main="", >> border >> = "red",add =TRUE) >> mtext("Fraction", side=2, line=2, cex=0.7) >> box() >> ====================================================== >> -- >> View this message in context: http://www.nabble.com/Help-needed%3A- >> Fraction-for-Histogram-%3E-1-----tp24150345p24150345.html >> Sent from the R help mailing list archive at Nabble.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. > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/Help-needed%3A-Fraction-for-Histogram-%3E-1-----tp24150345p24154095.html Sent from the R help mailing list archive at Nabble.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.
