layout, par(mfrow) - Combining Plots

R makes it easy to combine multiple plots into one overall graph, using either the
par( ) or layout( ) function.
With the par( ) function, you can include the option mfrow=c(nrows, ncols) to create a matrix of nrows x ncols plots that are filled in by row. mfcol=c(nrows, ncols) fills in the matrix by columns.

4 figures arranged in 2 rows and 2 columns
2行2列4图

attach(mtcars)
par(mfrow=c(2,2))
plot(wt,mpg, main="Scatterplot of wt vs. mpg")
plot(wt,disp, main="Scatterplot of wt vs disp")
hist(wt, main="Histogram of wt")
boxplot(wt, main="Boxplot of wt")

image.png

3 figures arranged in 3 rows and 1 column
3行1列3图

attach(mtcars)
par(mfrow=c(3,1))
hist(wt)
hist(mpg)
hist(disp)

One figure in row 1 and two figures in row 2
上1图下2图

attach(mtcars)
layout(matrix(c(1,1,2,3), 2, 2, byrow = TRUE))
hist(wt)
hist(mpg)
hist(disp)

image.png

One figure in row 1 and two figures in row 2
row 1 is 1/3 the height of row 2
column 2 is 1/4 the width of the column 1

attach(mtcars)
layout(matrix(c(1,1,2,3), 2, 2, byrow = TRUE),
widths=c(3,1), heights=c(1,2))
hist(wt)
hist(mpg)
hist(disp)

image.png

Add boxplots to a scatterplot

par(fig=c(0,0.8,0,0.8), new=TRUE)
plot(mtcars$wt, mtcars$mpg, xlab="Car Weight",
  ylab="Miles Per Gallon")
par(fig=c(0,0.8,0.55,1), new=TRUE)
boxplot(mtcars$wt, horizontal=TRUE, axes=FALSE)
par(fig=c(0.65,1,0,0.8),new=TRUE)
boxplot(mtcars$mpg, axes=FALSE)
mtext("Enhanced Scatterplot", side=3, outer=TRUE, line=-3)

image.png