show multiple plots from ggplot on one page in r

Question

I want to make multiple ggplot in a loop and show them on one plot.

for ( i in 1:8) {
    g <- ggplot(data=mtcars, aes(x=hp, y=wt))+
        geom_point()
         


        

Answer 1

Note that, in the loop you provided, the counter i isn't referenced in the plot, so you'll end up printing the same plot eight times!

If you have a bunch of different subsets of a single dataset and want to lay them out, you can follow @PKumar's comment and check out facetting in ggplot2. It essentially splits your data up into groups according to one or more of your columns and then lays them out in a grid or a ribbon.

On the other hand, if you have a bunch of a different plots that you want to combine on one page, there're a couple of packages that can make this happen:

• cowplot is a fairly mature package that can do this, and
• patchwork is a newer package that lets you lay plots out using arithmetic.

Hope those help!

Answer 2

You can save all the plot in a list then use either cowplot::plot_grid() or gridExtra::marrangeGrob() to put them in one or more pages

See also:

• Creating arbitrary panes in ggplot2 (patchwork, multipanelfigure & egg packages)

• Multiple plots in for loop

library(tidyverse)

# create a list with a specific length 
plot_lst <- vector("list", length = 8)

for (i in 1:8) {
  g <- ggplot(data = mtcars, aes(x = hp, y = wt)) +
    geom_point()
  plot_lst[[i]] <- g
}

# Combine all plots
cowplot::plot_grid(plotlist = plot_lst, nrow = 4)

library(gridExtra)
ml1 <- marrangeGrob(plot_lst, nrow = 2, ncol = 2)
ml1

^{Created on 2018-09-20 by the reprex package (v0.2.1.9000)}