Readme.md
In jtr13/ggformat: Reformats ggplot2 code

Joyce Robbins September 11, 2024

ggformat

This is a one function addin package. My motivation in writing it was to make it easier to clean up and style ggplot2 code.

Note: this is new – please report bugs or leave comments!

remotes::install_github("jtr13/ggformat")

Highlight code thats produce a single ggplot2 graph, run the addin “Format ggplot2 code”, and the code will be cleaned up and styled. For example,

# BEFORE
mtcars |> group_by(cyl) |> summarize(mean_mpg = mean(mpg)) |> ggplot(aes(factor(cyl),
mean_mpg)) + theme_bw(14) + geom_col() + labs(title = "mtcars", x = "number of cylinders", y = "average miles per gallon")

will become:

# AFTER
mtcars |>
  group_by(cyl) |>
  summarize(mean_mpg = mean(mpg)) |>
  ggplot(aes(factor(cyl), mean_mpg)) +
  geom_col() +
  labs(title = "mtcars", x = "number of cylinders", y = "average miles per gallon") +
  theme_bw(14)

|>s are followed by line breaks
Each ggplot2 function appears on its own line followed by a +. Misplaced +s, such as after the last function, are removed.
ggplot2 functions are sorted based on the ggplot2 template:

Labeling functions (ggtitle, labs, xlab, ylab, annotate) are placed between scales and themes. Guides are added between labeling functions and themes.

Source: https://github.com/rstudio/cheatsheets/raw/master/data-visualization.pdf

The specific sort order is:

##  [1] "%>%"      "|>"       "ggplot"   "geom_"    "stat_"    "coord_"  
##  [7] "facet_"   "scale_"   "xlim"     "ylim"     "ggtitle"  "labs"    
## [13] "xlab"     "ylab"     "annotate" "guides"   "theme_"   "theme"

If there are multiple instances of a function type, for example, multiple geoms, the current order is preserved.
You can easily set your own sort order by forking the project and changing the splitwords variable in ggformat.R.

THE BIG DIFFERENCE: Neither formatR nor styler change the order of ggplot2 functions.
formatR does not add line breaks after +s in ggplot2 code.
styler reformats long lines by putting each argument on its own line and indenting, for example:

ggplot() +
    geom_ribbon(data = ribbon, aes(
        ymin = min,
        ymax = max,
        x = x.ribbon,
        fill = 'lightgreen'
    )) +
    geom_line(data = ribbon, aes(x = x.ribbon, y = avg, color = 'black')) +
    geom_line(data = data, aes(x = x, y = new.data, color = 'red')) +
    scale_fill_identity(name = 'the fill',
                        guide = 'legend',
                        labels = c('m1')) +
    scale_colour_manual(
        name = 'the colour',
        values = c('black' = 'black', 'red' = 'red'),
        labels = c('c2', 'c1')
    ) +
    xlab('x') +
    ylab('density')

ggformat styles this code as:

ggplot() +
  geom_ribbon(data = ribbon, aes(ymin = min, ymax = max, x = x.ribbon, fill = 'lightgreen')) +
  geom_line(data = ribbon, aes(x = x.ribbon, y = avg, color = 'black')) +
  geom_line(data = data, aes(x = x, y = new.data, color = 'red')) +
  scale_fill_identity(name = 'the fill', guide = 'legend', labels = c('m1')) +
  scale_colour_manual(name = 'the colour', values = c('black' = 'black', 'red' = 'red'), labels = c('c2', 'c1')) +
  xlab('x') +
  ylab('density')

Note: I hope to add wrapping so long lines are broken apart after commas:

# NOT YET IMPLEMENTED
ggplot() +
  geom_ribbon(data = ribbon, aes(ymin = min, ymax = max, x = x.ribbon, fill = 'lightgreen')) +
  geom_line(data = ribbon, aes(x = x.ribbon, y = avg, color = 'black')) +
  geom_line(data = data, aes(x = x, y = new.data, color = 'red')) +
  scale_fill_identity(name = 'the fill', guide = 'legend', labels = c('m1')) +
  scale_colour_manual(name = 'the colour', values = c('black' = 'black', 'red' = 'red'),
    labels = c('c2', 'c1')) +
  xlab('x') +
  ylab('density')

+’s are cleaned up so there is exactly one + at the end of every line except the last, and lines ending in pipes. Specifically, double +’s are replaced with single +’s, +’s before special ggplot2 words are removed, +’s are added back at the ends of lines.