This question builds from a related post which shows how to easily store a plot as an r object with the %<a-% function from the pryr package. Great! However, I now want to create a multiplot that combines a base r plot with 2 ggplot figures. I am using grid.arrange below.
Using the base r cars data I can make two ggplot figures.
library(ggplot2)
library(pryr)
library(gridExtra)
Fig1 <- qplot(speed, data=cars, geom="histogram")
Fig2 <- qplot(dist, speed, data=cars, geom="point")
I then make a figure with plot, and save the figure as an object using the %<a-% function from the pryr package. Slick.
Fig3 %<a-% plot(cars$speed, cars$dist)
Fig3
Lastly, I want to combine the 3 figures into a single plot as shown below.
Figs <- grid.arrange(Fig1, Fig2, Fig3,
layout_matrix = rbind(c(1,1,1,2,2), c(1,1,1,2,2), c(3,3,3,3,3)))
The code produces the following error:
Error in gList(list(grobs = list(list(x = 0.5, y = 0.5, width = 1, height = 1, :
only 'grobs' allowed in "gList"
How can I save an base r plot to be combined with additional ggplot figures?
As correctly noted by @MrFlick, the accepted answer linked here is a better approach than the %<a-% function which does not store a grid.
The code below produces the desired result.
library(ggplot2)
library(gridExtra)
library(gridGraphics)
library(grid)
Fig1 <- qplot(speed, data=cars, geom="histogram")
Fig2 <- qplot(dist, speed, data=cars, geom="point")
plot(cars$speed, cars$dist)
grid.echo()
Fig3 <- grid.grab()
Figs <- grid.arrange(Fig1, Fig2, Fig3,
layout_matrix = rbind(c(1,1,1,2,2), c(1,1,1,2,2), c(3,3,3,3,3)))