r plot one histogram above another

I would argue that one of the great things about ggplot2 is that it's intuitive and users can spend more time making quick and easy visualisations like this and less time worrying about the code.

Base R solution

x1<-rnorm(1000,50,10) x2<-rnorm(1000,50,20) x3<-rnorm(1000,50,30) x4<-rnorm(1000,50,40) xMin=min(x1,x2,x3,x4) xMax=max(x1,x2,x3,x4) par(mfrow=c(4,1), oma = c(5,2,2,2), mar = c(3, 1, 1, 1)) hist(x1, xlim = c(xMin,xMax), col='#4281C3', main = NULL) hist(x2, xlim = c(xMin,xMax), col = '#008437', main = NULL) hist(x3, xlim = c(xMin,xMax), col= '#F49824', main = NULL) hist(x4, xlim = c(xMin,xMax), col = '#E42313', main = NULL) legend('bottom',legend=c("x1", "x2", "x3", 'x4'), fill=c("#4281C3", '#008437', "#F49824", '#E42313'), horiz = T, inset=c(0,-1), xpd=NA) 

ggplot2 solution

library(tidyr) library(ggplot2) df1 <- gather(data.frame(x1, x2,x3,x4) , 'variable', 'value') ggplot(df1) + geom_histogram(aes(x = value, fill = variable), colour = '#000000') + facet_wrap(.~ variable, nrow = 4) + scale_fill_manual(values = c("#4281C3", '#008437', "#F49824", '#E42313')) 

The key to ggplot2 is to have one column per variable, hence the use of tidyr::gather but we could equally have done:

df1 <- data.frame(value = c(x1,x2,x3,x4), variable = rep(c('x1','x2','x3','x4'), each =1000)) 

If you're going for absolute ground level basics then par() should help you plot several plots in the same window.

par(mfrow = c(4,1)) # breaking your graphic windows into 4 rows, 1 column hist(x1, xlim = c(xMin,xMax)) hist(x2, xlim = c(xMin,xMax)) hist(x3, xlim = c(xMin,xMax)) hist(x4, xlim = c(xMin,xMax)) 

This will plot every histogram above the next but they will have their own legends etc. To reset the window parameters use dev.off(). For more complex methods that look much nicer, ggplot is definitely the go-to, there are countless simple guides online.