strip.text angle parameter does not work in conjuction with facet_grid switch

[zlskidmore]

Hi,

I've noticed that it is not possible to rotate strip text when forcing strip text to the left hand side of the plot using facet grid. For example:

ggplot(mtcars, aes(disp, hp)) + geom_point() + facet_grid(cyl~carb, switch="y") + theme(strip.text.y=element_text(angle=90))

ggplot(mtcars, aes(disp, hp)) + geom_point() + facet_grid(cyl~carb, switch="y") + theme(strip.text.y=element_text(angle=0))

does nothing, however removing switch="y" and rotating the text seems fine:

ggplot(mtcars, aes(disp, hp)) + geom_point() + facet_grid(cyl~carb) + theme(strip.text.y=element_text(angle=90))

ggplot(mtcars, aes(disp, hp)) + geom_point() + facet_grid(cyl~carb) + theme(strip.text.y=element_text(angle=0))

ggplot2 version is 3.3.2

[smouksassi]

Try
strip.text.y.left

[clauswilke]

As a general rule, these kinds of questions are more appropriate for the R Studio community or stackoverflow.

[zlskidmore]

Yes I see now, my appologies.

I didn't see that documented in the current docs and just assumed it was a bug.

Thanks again!

[slowkow]

Here’s my attempt to display the problem and the workaround.

Problem

The angle for strip text is discarded when we use facet_grid(switch = "y").

Let's start with dummy data, and load ggplot2.

set.seed(1)
d <- data.frame(
  i = rep(1:10, 5),
  j = rep(1:5, each = 10),
  x = rnorm(50),
  z = rep(c("a", "a", "b", "b", "c"), each = 10)
)

library(ggplot2)

Here's the base plot.

Notice: we set the angle for strip.text.y to 0.

p <- ggplot(d) +
  geom_tile(
    data = d,
    mapping = aes(x = i, y = j, fill = x)
  ) +
  theme(
    strip.text.y = element_text(size = 20, angle = 0),
    axis.text = element_blank(),
    axis.ticks = element_blank()
  )

As long as we do not use switch = "y", the plot looks OK:

p + facet_grid(
  rows = vars(z), scales = "free", space = "free"
)

Notice what happens when we add switch = "y":

• the angle is set back to 90 instead of 0

• the size is still set to 20

So, size is preserved but angle is discarded.

Is this expected behavior?

p + facet_grid(
  rows = vars(z), scales = "free", space = "free",
  switch = "y"
)

Workaround

Here’s the workaround: use theme(strip.text.y.left) instead of theme(strip.text.y).

p + facet_grid(
  rows = vars(z), scales = "free", space = "free",
  switch = "y"
) +
  theme(
    strip.text.y.left = element_text(size = 20, angle = 0)
  )

^{Created on 2021-07-06 by the reprex package (v0.3.0)}

Session info

devtools::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value                       
#>  version  R version 4.0.3 (2020-10-10)
#>  os       macOS Catalina 10.15.7      
#>  system   x86_64, darwin17.0          
#>  ui       X11                         
#>  language (EN)                        
#>  collate  en_US.UTF-8                 
#>  ctype    en_US.UTF-8                 
#>  tz       America/New_York            
#>  date     2021-07-06                  
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version    date       lib source                             
#>  assertthat    0.2.1      2019-03-21 [2] CRAN (R 4.0.2)                     
#>  blob          1.2.1      2020-01-20 [2] CRAN (R 4.0.2)                     
#>  callr         3.5.1      2020-10-13 [2] CRAN (R 4.0.2)                     
#>  cli           2.3.1      2021-02-23 [1] CRAN (R 4.0.3)                     
#>  colorspace    2.0-0      2020-11-11 [2] CRAN (R 4.0.2)                     
#>  crayon        1.4.1      2021-02-08 [1] CRAN (R 4.0.2)                     
#>  curl          4.3        2019-12-02 [2] CRAN (R 4.0.1)                     
#>  DBI           1.1.0      2019-12-15 [2] CRAN (R 4.0.2)                     
#>  debugme       1.1.0      2017-10-22 [1] CRAN (R 4.0.2)                     
#>  desc          1.2.0      2018-05-01 [2] CRAN (R 4.0.2)                     
#>  devtools      2.3.0      2020-04-10 [2] CRAN (R 4.0.2)                     
#>  digest        0.6.27     2020-10-24 [2] CRAN (R 4.0.2)                     
#>  dplyr         1.0.4      2021-02-02 [1] CRAN (R 4.0.2)                     
#>  ellipsis      0.3.1      2020-05-15 [2] CRAN (R 4.0.2)                     
#>  evaluate      0.14       2019-05-28 [2] CRAN (R 4.0.1)                     
#>  fansi         0.4.2      2021-01-15 [1] CRAN (R 4.0.2)                     
#>  farver        2.0.3      2020-01-16 [2] CRAN (R 4.0.2)                     
#>  fs            1.5.0      2020-07-31 [1] CRAN (R 4.0.2)                     
#>  generics      0.1.0      2020-10-31 [2] CRAN (R 4.0.2)                     
#>  ggplot2     * 3.3.5      2021-06-25 [1] CRAN (R 4.0.2)                     
#>  glue          1.4.2      2020-08-27 [2] CRAN (R 4.0.2)                     
#>  gtable        0.3.0      2019-03-25 [2] CRAN (R 4.0.2)                     
#>  highr         0.8        2019-03-20 [2] CRAN (R 4.0.2)                     
#>  htmltools     0.5.1.1    2021-01-22 [1] CRAN (R 4.0.2)                     
#>  httr          1.4.2      2020-07-20 [2] CRAN (R 4.0.2)                     
#>  knitr         1.31       2021-01-27 [1] CRAN (R 4.0.2)                     
#>  labeling      0.4.2      2020-10-20 [2] CRAN (R 4.0.2)                     
#>  lifecycle     1.0.0      2021-02-15 [1] CRAN (R 4.0.2)                     
#>  magrittr      2.0.1.9000 2020-12-15 [1] Github (tidyverse/magrittr@bb1c86a)
#>  memoise       1.1.0.9000 2020-12-15 [1] Github (r-lib/memoise@0901e3f)     
#>  mime          0.10       2021-02-13 [1] CRAN (R 4.0.2)                     
#>  munsell       0.5.0      2018-06-12 [2] CRAN (R 4.0.2)                     
#>  pillar        1.5.0      2021-02-22 [1] CRAN (R 4.0.3)                     
#>  pkgbuild      1.1.0      2020-07-13 [2] CRAN (R 4.0.2)                     
#>  pkgconfig     2.0.3      2019-09-22 [2] CRAN (R 4.0.2)                     
#>  pkgload       1.1.0      2020-05-29 [2] CRAN (R 4.0.2)                     
#>  prettyunits   1.1.1      2020-01-24 [2] CRAN (R 4.0.2)                     
#>  processx      3.4.5      2020-11-30 [2] CRAN (R 4.0.2)                     
#>  ps            1.5.0      2020-12-05 [2] CRAN (R 4.0.2)                     
#>  purrr         0.3.4      2020-04-17 [2] CRAN (R 4.0.2)                     
#>  R6            2.5.0      2020-10-28 [2] CRAN (R 4.0.2)                     
#>  remotes       2.2.0      2020-07-21 [1] CRAN (R 4.0.2)                     
#>  rlang         0.4.10     2020-12-30 [1] CRAN (R 4.0.2)                     
#>  rmarkdown     2.6        2020-12-14 [1] CRAN (R 4.0.2)                     
#>  rprojroot     2.0.2      2020-11-15 [2] CRAN (R 4.0.2)                     
#>  scales        1.1.1      2020-05-11 [2] CRAN (R 4.0.2)                     
#>  sessioninfo   1.1.1      2018-11-05 [2] CRAN (R 4.0.2)                     
#>  stringi       1.5.3      2020-09-09 [2] CRAN (R 4.0.2)                     
#>  stringr       1.4.0      2019-02-10 [2] CRAN (R 4.0.2)                     
#>  testthat      3.0.0      2020-10-31 [2] CRAN (R 4.0.2)                     
#>  tibble        3.0.6      2021-01-29 [1] CRAN (R 4.0.2)                     
#>  tidyselect    1.1.0      2020-05-11 [2] CRAN (R 4.0.2)                     
#>  usethis       1.6.1      2020-04-29 [2] CRAN (R 4.0.2)                     
#>  utf8          1.1.4      2018-05-24 [2] CRAN (R 4.0.2)                     
#>  vctrs         0.3.6      2020-12-17 [1] CRAN (R 4.0.2)                     
#>  withr         2.4.1      2021-01-26 [1] CRAN (R 4.0.2)                     
#>  xfun          0.21       2021-02-10 [1] CRAN (R 4.0.2)                     
#>  xml2          1.3.2      2020-04-23 [2] CRAN (R 4.0.2)                     
#>  yaml          2.2.1      2020-02-01 [2] CRAN (R 4.0.2)                     
#> 
#> [1] /Users/kamil/Library/R/4.0/library
#> [2] /Library/Frameworks/R.framework/Versions/4.0/Resources/library

[karawoo]

This is expected behavior.

Theme elements only inherit values from higher levels if they are not explicitly set themselves. theme_grey() explicitly sets the angle of strip.text.y.left to 90. So you need to edit strip.text.y.left if you want to change the angle for strip text on the left.

theme_grey() does not explicitly set the size for strip.text.y.left, nor anything for strip.text.y.right, so those will inherit from strip.text.y.

If you're interested in hearing a bit more about this, I covered it in my rstudio::global talk: https://www.rstudio.com/resources/rstudioglobal-2021/always-look-on-the-bright-side-of-plots/