When setting "scales" in facet_grid, the horizontal justification of the axis labels shifts among the panels

[ujtwr]

Case1

Panel "F1" has 3 values and Panel "F2" has other 3 values.
We use facet_grid without "scale" option, Axis Y of both panels has same 6 values. So, if we set "hjust = 0" in "element_text" on "axis.text.y", Text of Y axis are aligned left.

tibble(
  F = c(rep("F1", 3), rep("F2", 3)),
  Y = c("AAAAAAAAAAAAAAAAAAA", "BBBBB", "CCCCCCCCC", "DDDDD", "EEEEEEEE", "FFF"),
  Cnt = c(10, 20, 30, 50, 40 ,60)
) %>% 
  ggplot(mapping = aes(y = Y, x = Cnt)) +
  geom_col() +
  facet_grid(
    rows = vars(F)
  ) +
  theme(
    axis.text.y = element_text(hjust = 0)
  )

Case2

Next, we add an option "scales = free_y" on facet_grid function, panel F1 and F2 has other values that have different width. So, the alignment position of the text varies depending on the panel.

tibble(
  F = c(rep("F1", 3), rep("F2", 3)),
  Y = c("AAAAAAAAAAAAAAAAAAA", "BBBBB", "CCCCCCCCC", "DDDDD", "EEEEEEEE", "FFF"),
  Cnt = c(10, 20, 30, 50, 40 ,60)
) %>% 
  ggplot(mapping = aes(y = Y, x = Cnt)) +
  geom_col() +
  facet_grid(
    rows = vars(F),
    scales = "free_y"
  ) +
  theme(
    axis.text.y = element_text(hjust = 0)
  )

[teunbrand]

Hi there, thanks for the report! To be clear, both axes have left-aligned text, it is just that there is additional space on the bottom axes due to misalignment with the top axis.

The issue occurs because the two guides are drawn independently of oneanother, unaware of dimensions of other axes in the same direction. Having dabbled a bit in the guide code, I can say with some confidence that it'll not be straightforward to line up the labels.

[ujtwr]

For example, when moving the label of a panel to the left side, I would like the Y-axis text to align along the panel.

tibble(
  F = c(rep("F1", 3), rep("F2", 3)),
  Y = c("AAAAAAAAAAAAAAAAAAA", "BBBBB", "CCCCCCCCC", "DDDDD", "EEEEEEEE", "FFF"),
  Cnt = c(10, 20, 30, 50, 40 ,60)
) %>% 
  ggplot(mapping = aes(y = Y, x = Cnt)) +
  geom_col() +
  facet_grid(
    rows = vars(F),
    scales = "free_y",
    switch = "y"
  ) +
  theme(
    axis.text.y = element_text(hjust = 0),
    strip.text.y.left = element_text(angle = 0),
    strip.placement = "outside"
  )

[teunbrand]

Thanks, the intent is clear 👍 It is implementation-wise that this could be tricky.

[smouksassi]

in your case patchwork can help you doing what you want

library(patchwork)
library(ggplot2)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union

dataggplot <- tibble(
  F = c(rep("F1", 3), rep("F2", 3)),
  Y = c("AAAAAAAAAAAAAAAAAAA", "BBBBB", "CCCCCCCCC", "DDDDD", "EEEEEEEE", "FFF"),
  Cnt = c(10, 20, 30, 50, 40 ,60)
) 
a1 <-   ggplot(dataggplot %>% 
           filter(F=="F1"),
         mapping = aes(y = Y, x = Cnt)) +
  geom_col() +
  facet_grid(
    rows = vars(F),
    scales = "free_y",
    switch = "y"
  ) +
  theme(
    axis.text.y = element_text(hjust = 0),
    strip.text.y.left = element_text(angle = 0),
    strip.placement = "outside"
  )+
  coord_cartesian(xlim=c(NA,60))+
  theme(axis.title.x = element_blank(),axis.ticks.x.bottom = element_blank(),
        axis.text.x.bottom = element_blank())
a2 <- ggplot(dataggplot %>% 
         filter(F=="F2"),
       mapping = aes(y = Y, x = Cnt)) +
  geom_col() +
  facet_grid(
    rows = vars(F),
    scales = "free_y",
    switch = "y"
  ) +
  theme(
    axis.text.y = element_text(hjust = 0),
    strip.text.y.left = element_text(angle = 0),
    strip.placement = "outside"
  )+
  coord_cartesian(xlim=c(NA,60))

a1/a2 +
  plot_layout(axis_titles = "collect_y")

^{Created on 2024-04-04 with reprex v2.1.0}

[teunbrand]

@smouksassi I think the intent is to change the 'whitespace' area for the lower series of axis labels from left to right w.r.t the labels. That'd left-align all the y-axis labels. Like the following picture that I have expertly edited using MS paint:

@ujtwr please correct me if I'm misinterpreting the request

[smouksassi]

a quick fix would be to manually pad with spaces until you have a simiar strwidth
this is not a solution but prevent you form needing to manually edit your plot

library(stringr)
library(ggplot2)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union


dataggplot <- tibble(
  F = c(rep("F1", 3), rep("F2", 3)),
  Y = c("AAAAAAAAAAAAAAAAAAA", "BBBBB", "CCCCCCCCC", "DDDDD", "EEEEEEEE",
        "FFF                                       "),
  Cnt = c(10, 20, 30, 50, 40 ,60)
) %>% 
  mutate(Ypad= stringr::str_pad(Y, width = 20, side = "right",pad=" ",use_width=FALSE))

strwidth(dataggplot$Y)
#> Error in strwidth(dataggplot$Y): plot.new has not been called yet

ggplot(dataggplot,
               mapping = aes(y = Y, x = Cnt)) +
  geom_col() +
  facet_grid(
    rows = vars(F),
    scales = "free_y",
    switch = "y"
  ) +
  theme(text = element_text(size=16),
    axis.text.y = element_text(hjust = 0),
    strip.text.y.left = element_text(angle = 0),
    strip.placement = "outside"
  )

^{Created on 2024-04-04 with reprex v2.1.0}

[ujtwr]

@smouksassi
Thank you for the suggestion. I have already tried it, but I'm a Japanese user, so sometimes there can be misalignment when padding with white spaces.

[Aciole-David]

Idk if too late, sorry, but there is an easier, two-liner way to pad the labels from this stack overflow :

credits to Marius and Gregor Thomas

before fix:

test <- data.frame(label = c('a', 'ab', 'a', 'abc', 'abcd', 'abcde', 
                             'abcdef', 'abcdefg', 'abcdefgh', 
                             'abcdefghi', 'abcdefghij', 
                             'abcdefghijkfiutdkjgbhcvi'),
                   xdum = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12),
                   facett = rep(c("Facet 1", "Facet 2", "Facet 3"), 4), 
                   data = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12))

ggplot(test, aes(x = xdum, y = label, label = data)) + 
  facet_grid(facett~., scales = "free", space = "free") + 
  geom_tile() + 
  theme(axis.ticks = element_blank(), axis.text.y = element_text(hjust = 0))

fixed

You can pad the labels out to the length of the longest string and then display them in a fixed-width font:

max_width = max(nchar(as.character(test$label)))
test$label_padded = sprintf(paste0("%-", max_width, "s"), test$label)

# (Ignore this if not on Windows)
windowsFonts(Consolas = "Consolas")
ggplot(test, aes(x = xdum, y = label_padded, label = data)) + 
    facet_grid(facett~., scales = "free", space = "free") + 
    geom_tile() + 
    theme(axis.ticks = element_blank(), 
          axis.text.y = element_text(hjust = 0, family = "Consolas"))