Multiple equally sized plots in an RMarkdown document

Question

I would like to align the area of several plots, each of them created by separate chunks in an RMarkdown document (preferably .html) "nicely". My problem: Because of the different lengths of the y-axis texts. The plotted area doesn't overlap perfectly (A pity because my actual x-axis is months).

Setting the fig.width= and out.width= don't help here as they consider the axis text lengths.

Dummy Data chunk:

require(ggplot2)

df = expand.grid(y = LETTERS,
                 x = paste0('A', 1:10),
                 stringsAsFactors = FALSE)
set.seed(42)
df$fill = rnorm(nrow(df))
df2 = df
df2$y = unlist(lapply(lapply(df2$y, function(x) rep(x, 10)), paste0, collapse = ''))

Plot-Chunk1:

gg1 = ggplot(df, aes(y = y, x = x, fill = fill)) +
  geom_tile()
gg1

Plot-Chunk2:

gg2 = ggplot(df2, aes(y = y, x = x, fill = fill)) +
  geom_tile()
gg2

The plots in the RMarkdown document should look like that (red lines highlight the desired alignment):

I achieved this with the patchwork package. However, like this I can only use one chunk and not multiple.

Patchwork-Plot-Chunk:

require(patchwork)

gg1 / gg2 +
  plot_annotation(tag_levels = 'A')

Answer 1

The patchwork package also includes the function align_patches() which works similar to cowplot::align_plots().

gg_l = patchwork::align_patches(gg1,
                                gg2)

Plot-Chunk1:

gg_l[[1]]

Plot-Chunk2:

gg_l[[2]]

Data from question.

Answer 2

Edited (tidier?) solution: cowplot::align_plots

Having a bit of a play around with cowplot::align_plots, it would be possible to set a standard panel width to use across all graphs. But to do this across chunks when you're constructing each graph 'blind' to the forthcoming ones, you could create a 'template' plot with labels as wide as needed (gg_set below). Each subsequent graph would then adopt the sizing of this unused plot:

require(ggplot2)

df  <-  expand.grid(y = LETTERS,
                    x = paste0('A', 1:10),
                    stringsAsFactors = FALSE)
set.seed(42)
df$fill = rnorm(nrow(df))

df2  <-  df
df2$y  <-
  unlist(lapply(lapply(df2$y, function(x)
    rep(x, 5)), paste0, collapse = ''))


# df for setting max size needed - might need experimented with
dfset  <-  df
dfset$y  <-
  unlist(lapply(lapply(df$y, function(x)
    rep(x, 10)), paste0, collapse = ''))


# 'template' plot
gg_set <-  ggplot(dfset, aes(y = y, x = x, fill = fill)) +
  geom_tile()


require(cowplot)

# Chunk 1
gg1  <-  ggplot(df, aes(y = y, x = x, fill = fill)) +
  geom_tile()

ggs <- align_plots(gg_set, gg1, align = "v")

# Only extracting relevant graph.
ggdraw(ggs[[2]])

# Chunk 2
gg2  <-  ggplot(df2, aes(y = y, x = x, fill = fill)) +
  geom_tile()

ggs <- align_plots(gg_set, gg2, align = "v")

ggdraw(ggs[[2]])

^{Created on 2021-12-17 by the reprex package (v2.0.1)}

Untidy former solution

I've previously used an admittedly messy solution, which really just involves padding all labels with blank rows above and below to greater than the max length:

require(ggplot2)
#> Loading required package: ggplot2

df  <-  expand.grid(y = LETTERS,
                    x = paste0('A', 1:10),
                    stringsAsFactors = FALSE)
set.seed(42)
df$fill = rnorm(nrow(df))
df2  <-  df
df2$y  <-
  unlist(lapply(lapply(df2$y, function(x)
    rep(x, 10)), paste0, collapse = ''))


df$y <-
  paste0(paste0(rep(" ", 40), collapse = ""), "\n", df$y, "\n", paste0(rep(" ", 40)))
df2$y <-
  paste0(paste0(rep(" ", 40), collapse = ""), "\n", df2$y, "\n", paste0(rep(" ", 40)))

gg1  <-  ggplot(df, aes(y = y, x = x, fill = fill)) +
  geom_tile()
gg1

gg2 <-  ggplot(df2, aes(y = y, x = x, fill = fill)) +
  geom_tile()
gg2

I would hope their is a more formal solution which allows a static panel sizing, and I look forward to hearing other answers. But had used this as a quick fix!

^{Created on 2021-12-17 by the reprex package (v2.0.1)}