如何在 R 中的两列中打印大量 ggplot 图形而不将它们展平？

Question

For example, if you run the following, you will see that grid.arrange squeezes all 20 ggplot plots into one figure making them unreadable.

Is there a way to create a tall figure that can contain dozens of these plots, or is there an easy way to get them to print four at a time 2 by 2 via grid.arrange output until there's no more in the list?

The number of figures in the list may or may not be divisible by four. For example, if I had 9 plots in the list, it would need to print a 2 by 2 image, another 2 by 2 image, and then the last one.

library(gridExtra)
library(ggplot2)

#Create the dataframe.
df<-data.frame(matrix(rexp(200), 10))
colnames(df)<-c("aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj", "aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj")

#Create the ggplots in a loop.
hlist<-list()
for(i in 1:ncol(df)){
  
  hplot<-eval(substitute(ggplot(df[i], aes(x=df[,i])) + geom_histogram(),list(i = i)))
  
  hlist[[i]]<-hplot
}

#Print the plots.
grid.arrange(grobs = hlist, ncol = 2)

Answer 1

Try this approach using patchwork to create a 2x2 plots creating indexes after storing all plots in a new list. With index vectors you can set a loop and use wrap_plots() to arrange them. Here the code:

library(ggplot2)
library(patchwork)

#Create the dataframe.
df<-data.frame(matrix(rexp(200), 10))
colnames(df)<-c("aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj", "aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj")

#Create the ggplots in a loop.
hlist<-list()
for(i in 1:ncol(df)){
  
  hplot<-eval(substitute(ggplot(df[i], aes(x=df[,i])) + geom_histogram(),list(i = i)))
  
  hlist[[i]]<-hplot
}
#Print the plots.
vec <- seq(1,length(hlist),by=4)
vec2 <- seq(4,length(hlist),by=4)
#New list
hlist2 <- list()
#Loop
for(i in 1:length(vec))
{
  hlist2[[i]] <- wrap_plots(hlist[vec[i]:vec2[i]],ncol = 2)
}
#Arrange
finalplot <- wrap_plots(hlist2,ncol = 2)

Output:

All the 2x2 plots are stored in hlist2 .

Answer 2

I found the solution for creating a list of plot pages then printing each page using marrangeGrob:

library(gridExtra)
library(ggplot2)

#Create the dataframe.
df<-data.frame(matrix(rexp(200), 10))
colnames(df)<-c("aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj", "aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj")

#Create the ggplots in a loop.
hlist<-list()
for(i in 1:ncol(df)){
  
  hplot<-eval(substitute(ggplot(df[i], aes(x=df[,i])) + geom_histogram(),list(i = i)))
  
  hlist[[i]]<-hplot
}

#Uses marrangeGrob to first store them in multiple pages.
glist<-marrangeGrob(hlist, nrow=2, ncol=2)

#Print each page one at a time until through all pages.
for(i in 1:length(glist)){grid.arrange(grobs = glist[i], ncol = 1)}