CODEWITHSUNDEEP
rplotggplot2histogram
Gooze
Gooze

Reputation: 110

Plotting multiple histograms quickly in R

For exploratory analysis, its often useful to quickly plot multiple variables in one grid. An easy way to do this is to:

data(mtcars)    
hist(mtcars[,c(1,2,3,4)])

enter image description here

However, it becomes difficult to adjust breaks and axes to maintain consistency i.e.

hist(mtcars[,c(1,2,3,4)], breaks = 10)

does not effect the histograms. Is there an easy work around this or an easy way to do this in ggplot2?

Upvotes: 2

Views: 28548

Answers (2)

Paul Endymion
Paul Endymion

Reputation: 561

This is how to do it with hist() : 

lapply(mtcars[1:4], FUN=hist)

However I prefer to store plots in R objects with ggplot2 and display plot lists with cowplot::plotgrid() :

list <-lapply(1:ncol(mtcars),
              function(col) ggplot2::qplot(mtcars[[col]],
                                           geom = "histogram",
                                           binwidth = 1))

cowplot::plot_grid(plotlist = list)

Upvotes: 7

Paolo
Paolo

Reputation: 3955

With ggplot2 you can use facet_wrap to create a grid based on other variables.

For example:

library(ggplot2)

data(mtcars)

ggplot(data = mtcars) +
    geom_histogram(aes(x = mpg), bins = 4, colour = "black", fill = "white") +
    facet_wrap(~ gear)

example histogram with facets

And you can use the bins parameter to easily set how many breaks you want.

Upvotes: 4

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