R & R Studio tricks

by khupfeld
on August 15, 2020

Below are miscellaneous tricks for coding in R and for using the R Studio interface. Also, to get started, here’s a helpful link about basics in authoring R Markdown code: https://rmarkdown.rstudio.com/authoring_basics.html

Code Formatting

Folding the code blocks. This is really useful if you’re working with a long file with many lines of code. When you first open a file you previously wrote, it’ll have all of the code blocks unfolded. If you just want to go back to one section and e.g., change a figure line color, it’s way easier to see the relevant code section with folded blocks. Either via the Edit menu or keyboard shortcut you can quickly fold all of the code blocks and then only unfold the ones you need to work with.

unfolded code

Keyboard: Mac: COMMAND + OPTION + O Windows: ALT + O

Menus: Edit -> Folding -> Collapse All

menu options to fold
et voila! nicely folded

Viewing the outline. This is also useful if you’re working with a lot of code. You can pull up a sidebar with an outline of your code.

Keyboard: Mac: COMMAND + SHIFT + O Windows: CTRL + SHIFT + O

see the outline on the right

Printing Useful Information

Print the R version you’re using. 

R.version

Print the citation for a package.

citation(package="psych")

Plotting

Pull the x and y axis limits from a ggplot.

ggplot_build(g1)$layout$panel_scales_x[[1]]$range$range
ggplot_build(g1)$layout$panel_scales_y[[1]]$range$range

Coding

R recognizes partial variable names if unique. This is less of a tip (because it’s bad practice) and more of something to note. If you have a long-ish variable name that’s unique, R will let you call that variable with only the first part of its unique name. For instance:

I have two different variables with similar names; if I start typing the common prefix to their names > tab > R pulls them both up as suggestions; nice
However, once I get to the unique part of the longer variable name, R lets you call that variable without using its whole name. You just need to type out enough for the name to be unique from other variables. Weird!

I’m not sure I’d really recommend doing this… because you obviously want to be super sure you’re calling the intended variable for whatever function you’re running. However, it’s something to note that R does — because, for instance, it was driving me crazy until I realized this was the case; I thought that R was loading the wrong dataset with differently named variables, or that something else funky was going on!

Categories:

R

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RR Studio
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