Specify Widths and Heights of Plots with Grid.Arrange

Specify widths and heights of plots with grid.arrange

Try plot_grid from the cowplot package:

library(ggplot2)
library(gridExtra)
library(cowplot)
p1 <- qplot(mpg, wt, data=mtcars)
p2 <- p1
p3 <- p1 + theme(axis.text.y=element_blank(), axis.title.y=element_blank())
plot_grid(p1, p2, p3, align = "v", nrow = 3, rel_heights = c(1/4, 1/4, 1/2))

How to create plots with same widths (excluding legend) with grid.arrange

You could add some spacing legend labels of plot A. This will also keep the legend key boxes nicely aligned, and the labels effectively right-justified.

#Plot A
A<- ggplot(df_a, aes(x=Timestamp, y=Frequency, fill=Topic)) + 
  scale_x_date(date_breaks = '1 month', date_labels = "%b")+
  geom_area(alpha=0.6 , size=1, colour="black", position = position_fill())+
  ggtitle("Plot A") +
  theme(legend.spacing.x = unit(6.1, 'mm'))

# Plot B
B<- ggplot(df_b, aes(x=Timestamp, y=Frequency, fill=Topic)) + 
  scale_x_date(date_breaks = '1 month', date_labels = "%b")+
  geom_area(alpha=0.6 , size=1, colour="black", position = position_fill())+
  ggtitle("Plot B")

title=text_grob("", size = 13, face = "bold") #main title of plot
grid.arrange(grobs = list(A, B), ncol=1, common.legend = TRUE, legend="bottom",
             top = title, widths = unit(0.9, "npc"))

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Packages and data used

library(gridExtra)
library(ggplot2)
library(ggpubr)

set.seed(1)

df_a <- data.frame(Timestamp = rep(seq(as.Date('2022-01-01'), 
                                       as.Date('2022-12-01'),
                                       by = 'month'), 5),
                   Frequency = runif(60, 0.1, 1),
                   Topic = rep(LETTERS[1:5], each = 12))

df_b <- data.frame(Timestamp = rep(seq(as.Date('2022-01-01'), 
                                       as.Date('2022-12-01'),
                                       by = 'month'), 5),
                   Frequency = runif(60, 0.1, 1),
                   Topic = rep(c('AAA', 'BBB', 'CCC', 'DDD', 'EEE'), each = 12))

Increase grid.arrange plot size

In your markdown/knitr chunk, try a value like fig.height = 10

```{r, fig.height = 10}
# Small fig.width
ggplot(cars, aes(speed, dist)) + geom_point()
```

Or you can set the default height for all the figures in an Rmd file

knitr::opts_chunk$set(fig.height = 10)

References

• https://community.rstudio.com/t/rmarkdown-rnotebook-text-in-graphs-too-small-lines-to-thin-after-update/123741/3
• http://zevross.com/blog/2017/06/19/tips-and-tricks-for-working-with-images-and-figures-in-r-markdown-documents/
• Plot size and resolution with R markdown, knitr, pandoc, beamer
• https://rmd4sci.njtierney.com/customising-your-figures.html

altering height of rows produced by grid.arrange when nrow=1

You can also specify relative heights and widths using the heights and widths arguments to grid.arrange like so:

grid.arrange(p1 , p2 , widths = unit(0.5, "npc") , heights=unit(0.5, "npc") , main="Title", ncol=2)

grid.arrange to display multiple facet_wrap plots - how do I make panel widths consistent?

One option would be to make use of the patchwork package. In case of your example code you could do

library(patchwork)

g1 / (g2 + plot_spacer()) 

As a more generalizable approach you could

1. Put your plots in a list
2. Make a vector containing the number of categories per group
3. Loop over the plot list, add a spacer to each plot and set the widths of each subplot and the spacer using plot_layout such that the panels align.

Note: To make the example more interesting I added a third group.

EDIT To color the points by group you could make use of a named vector of colors, which assigns colors to groups. This way you assign the colors to the color argument of geom_point. In the code below I use the default ggplot2 colors, but you could set the colors as you like.

library(dplyr)
library(ggplot2)
library(forcats)
library(stringr)

x <- c(1, 2, 3, 4, 1, 2, 1:3)
y <- c(3, 3, 3, 3, 3, 3, 1:3)
category <- c("category a", "category b", "category c", "category d", "category e", "category f", "category d", "category e", "category f")
group <- c("group one", "group one", "group one", "group one", "group two", "group two", "group three", "group three", "group three")
df <- data.frame(x, y, category, group)

# Named vector of colors
colors <- scales::hue_pal()(length(unique(df$group)))
names(colors) <- unique(df$group)

p <- df %>% 
  # Set order of group
  mutate(group = forcats::fct_inorder(group)) %>% 
  split(.$group) %>% 
  purrr::imap(function(.data, .title) {
    ggplot(.data, aes(x=x, y=y)) +
      geom_point(color = colors[.title]) +
      facet_wrap(~category, nrow=1) +
      labs(title = stringr::str_to_title(.title))  
  })

# Make a vector containing number of categories per group
ncat <- df %>% 
  group_by(group) %>% 
  summarise(n = n_distinct(category)) %>% 
  tibble::deframe()
ncat_max <- max(ncat)

library(patchwork)

p <- purrr::imap(p, function(x, y) {
  ncat <- ncat[[y]]
  n_spacer <- ncat_max - ncat
  # Add spacer to each plot and set widths
  x + plot_spacer() + plot_layout(ncol = 2, widths = c(ncat, n_spacer))
})

wrap_plots(p, nrow = length(p))

R - Adjust size of all plots included in a grid.arrange

Because patchwork aligns plots by the panels, the result is nice and stable when certain (axis) elements are missing. Example below:

library(ggplot2)
library(patchwork)
#> Warning: package 'patchwork' was built under R version 4.0.3

plot <- ggplot(mpg, aes(displ, cty)) + geom_point()

p1 <- plot + theme(axis.text.x = element_blank())
p2 <- plot + theme(axis.text.y = element_blank())
p3 <- plot + theme(axis.title.x = element_blank())
p4 <- plot + theme(axis.title.y = element_blank())

p1 + p2 + p3 + p4 + plot_layout(2, 2)

^{Created on 2021-04-04 by the reprex package (v1.0.0)}

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