How to merge tapply() and hist() in R?

Question

How does one appropriately merge the hist() and tapply() functions in R, in order to get histograms of data subsets? When I attempt this using the standard tapply() formula tapply(X, INDEX, FUN), I successfully get value outputs for each data subset, but I only get one histogram plot with the title 'Histogram of X[[4L]]'. How can I get separate histograms for each subset? Thanks,

Answer 1

Try this:

par(mfrow = c(2, 2))
tapply(iris$Sepal.Length, iris$Species, hist)

however, for multi-panel plots you might find the lattice or ggplot2 plackages more suitable.

library(lattice)
histogram(~ Sepal.Length | Species, iris)

library(ggplot2)
ggplot(iris, aes(Sepal.Length)) + geom_histogram() + facet_wrap(~ Species)