formatR: farewell to ugly R code

Yihui Xie 2010-04-13

It is not uncommon to see messy R code which is almost not human-readable like this:

 # rotation of the word "Animation"
# in a loop; change the angle and color
# step by step
for (i in 1:360) {
 # redraw the plot again and again
# rotate; use rainbow() colors
# pause for a while

Apparently it is pain reading unformatted R code, but on the other hand, it is natural for us to be lazy. I don’t care about adding spaces or indent to my raw R code – I’ll concentrate on programming first and format my code later. The R package formatR is intended to help us format our messy R code.

# formatR optionally depends on gWidgetsRGtk2
# please use the latest version of R (>=2.12.0)

## you will get an error if the package gWidgetsRGtk2 is not installed;
## then you need to install it

Then you can either paste your code into the text box or click the “Open” button to open an existing R code file. Click the “Convert” button and you are done!

formatR: unformatted R code

formatR: tidy R code

formatR: the Java GUI

There are several options in the “Preferences” panel, e.g. you can specify whether to keep comments or blank lines, or specify the width of the formatted R code.

No matter how messy your code looks like, formatR can make it tidy and structured as long as there are no syntax errors in your R code. If you prefer the command line interface, you may want to take a look at the function tidy_source() in this package.

Note that multi-byte characters (say, Chinese) are also supported in the GUI.