如何从一个数据框列表中制作多个ggplots，并将它们放在一个pdf页面上？

Question

I have a list of dataframes (eg a simple example below)

df1 <- data.frame(v1=c(1:5), v2=c(2:6))
df2 <- data.frame(v1=c(10:50), v2=c(20:60))
df3 <- data.frame(v1=c(100:500), v2=c(200:600))
df4 <- data.frame(v1=c(1000:5000), v2=c(2000:6000))
df.list <- list(df1, df2, df3, df4)

how can I use lapply function to generate x,y scatter plots for all dataframes in the list and then output as a one-page pdf? Thanks.

Answer 1

Something like this will do the trick

pdf("myplots.pdf")
par(mfrow=c(2,2))
lapply(df.list, function(x) plot(x=x[,1], y=x[,2])) 
dev.off()

ggplot solution

library(ggplot2)
library(grid)
library(gridExtra)
p <- lapply(df.list, function(d) ggplot(data = d, aes(x=v1, y=v2)) + geom_point() )

pdf("myplots2.pdf")
do.call("grid.arrange", p)
dev.off()