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.
