How do you use hist to plot relative frequencies in R?

Question

How do you use hist() to plot relative frequencies in R?

If I do the following, I will get a density plot, but I want a relative frequency plot:

a <- c(0,0,0,1,1,2)
hist(a, freq=FALSE)

I want to see a histogram with the following relative frequencies:

.5 for 0 to 1,

.33 for 1 to 2,

and .166 for 2 to 3.

Solution 1

you can try using the histogram() function in lattice

a <- c(0,0,0,1,1,2)
library(lattice)
histogram(a)

defaults to percent.

Solution 2

I've added a new function to the HistogramTools package on CRAN, PlotRelativeFrequency() which takes a histogram object and generates a relative frequency histogram plot. This is available now from R-Forge and will be in HistogramTools 0.3 for the next CRAN release.

Basically, you just need to make two modifications to the default histograms in R. First, you need to divide each count by the sum of all of the counts, and you need to replace the y-axis label to note that it is now plotting Relative Frequencies.

x<-runif(100)
h<-hist(x, plot=F)
h$counts <- h$counts / sum(h$counts)
plot(h, freq=TRUE, ylab="Relative Frequency")

Or, simply

install.packages("HistogramTools", repos="http://R-Forge.R-project.org")
library(HistogramTools)
PlotRelativeFrequency(hist(x, plot=F))

Solution 3

hist(a, breaks=c(0, 1, 2, 3), freq=FALSE, right=FALSE)

Solution 4

Not properly a traditional histogram...

h<-hist(yourdata)
plot(h$mids,100*h$counts/sum(h$counts),type="h")

Solution 5

histo<-hist(yourvariable)
barplot(histo$counts/n,col="white",space=0)->bp   # n=length(yourvariable)
axis(1,at=c(bp),labels=histo$mids)
title(ylab="Relative Frequency",xlab="Your Variable Name")

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Comments

[zoltanctoth]

What a pity that it uses such an ugly color as default :)