I am trying to align three plots (with different scales on the y-axis) on the left y-axis. In other words, I would like the red axis to be aligned:
However, the y-axis of the first plot does not align with the y-axis of the bottom left plot.
Code
# Libraries
library(tidyverse)
library(cowplot)
df1 <- data.frame(x = seq(0, 100, 1),
y = seq(100, 0, -1))
df2 <- data.frame(x = seq(0, 10, 0.1),
y = seq(1, 10^9, length.out = 101 ) )
p1 <- ggplot(data = df1) +
geom_line(aes(x = x, y = y))
p2 <- ggplot(data = df2) +
geom_line(aes(x = x, y = y))
combi_p2 <- plot_grid(p2, p2, nrow = 1)
plot_grid(p1, combi_p2, ncol = 1, axis = "l", align = "v")
Attempt to fix it
Using the information provided here, I rewrote the last part of the code:
require(grid) # for unit.pmax()
p1 <- ggplotGrob(p1) # convert to gtable
combi_p2 <- ggplotGrob(combi_p2) # convert to gtable
p1.widths <- p1$widths[1:3] # extract the first three widths,
# corresponding to left margin, y lab, and y axis
combi_p2.widths <- combi_p2$widths[1:3] # same for combi_p2 plot
max.widths <- unit.pmax(p1.widths, combi_p2.widths) # calculate maximum widths
p1$widths[1:3] <- max.widths # assign max. widths to p1 gtable
combi_p2$widths[1:3] <- max.widths # assign max widths to combi_p2 gtable
# plot_grid() can work directly with gtables, so this works
plot_grid(p1, combi_p2, labels = "AUTO", ncol = 1)
Sadly, I was not able to fix the alignment:
Question
How do I align the y-axis of the top plot with the left bottom plot using cowplot in R?
A cowplot
solution by Claus O. Wilke is presented here.
It is based on the align_plot
function, which first aligns the top plot with the left bottom plot along the y-axis. Then the aligned plots are passed to the plot_grid
function.
# Libraries
library(tidyverse)
library(cowplot)
df1 <- data.frame(x = seq(0, 100, 1),
y = seq(100, 0, -1))
df2 <- data.frame(x = seq(0, 10, 0.1),
y = seq(1, 10^9, length.out = 101 ) )
p1 <- ggplot(data = df1) +
geom_line(aes(x = x, y = y))
p2 <- ggplot(data = df2) +
geom_line(aes(x = x, y = y))
plots <- align_plots(p1, p2, align = 'v', axis = 'l')
bottom_row <- plot_grid(plots[[2]], p2, nrow = 1)
plot_grid(plots[[1]], bottom_row, ncol = 1)