R is a high-level programming language used primarily for statistical computingand graphics. The goal of the R Programming Style Guide is to make our R codeeasier to read, share, and verify.
The Google R Style Guide is a fork of theTidyverse Style Guide by Hadley Wickhamlicense. Google modificationswere developed in collaboration with the internal R user community. The rest ofthis document explains Google’s primary differences with the Tidyverse guide,and why these differences exist.
Syntax
Naming conventions
Google prefers identifying functions with BigCamelCase to clearly distinguishthem from other objects.
# GoodDoNothing <- function() { return(invisible(NULL))}
The names of private functions should begin with a dot. This helps communicateboth the origin of the function and its intended use.
# Good.DoNothingPrivately <- function() { return(invisible(NULL))}
We previously recommended naming objects with dot.case. We’re moving away fromthat, as it creates confusion with S3 methods.
Don’t use attach()
The possibilities for creating errors when using attach() are numerous.
Pipes
Right-hand assignment
We do not support using right-hand assignment.
# Badiris %>% dplyr::summarize(max_petal = max(Petal.Width)) -> results
This convention differs substantially from practices in other languages andmakes it harder to see in code where an object is defined. E.g. searching forfoo <- is easier than searching for foo <- and -> foo (possibly split overlines).
Use explicit returns
Do not rely on R’s implicit return feature. It is better to be clear about yourintent to return() an object.
# GoodAddValues <- function(x, y) { return(x + y)}# BadAddValues <- function(x, y) { x + y}
Qualifying namespaces
Users should explicitly qualify namespaces for all external functions.
We discourage using the @import Roxygen tag to bring in all functions into aNAMESPACE. Google has a very big R codebase, and importing all functions createstoo much risk for name collisions.
While there is a small performance penalty for using ::, it makes it easier tounderstand dependencies in your code. There are some exceptions to this rule.
- Infix functions (
%name%) always need to be imported. - Certain
rlang pronouns, notably .data, need to be imported. - Functions from default R packages, including
datasets, utils, grDevices, graphics, stats and methods. If needed, you can @import the full package.
When importing functions, place the @importFrom tag in the Roxygen headerabove the function where the external dependency is used.
Documentation
Package-level documentation
All packages should have a package documentation file, in apackagename-package.R file.
FAQs
At Google, to manage our codebase, we maintain a set of style guides that define our rules. Rules are laws.
What is the function of the R style guide? ›
The goal of the R Programming Style Guide is to make our R code easier to read, share, and verify. The Google R Style Guide is a fork of the Tidyverse Style Guide by Hadley Wickham license. Google modifications were developed in collaboration with the internal R user community.
What is the line length for R style guide? ›
2.1 Line Length
Strive to limit your code to 80 characters per line. This fits comfortably on a printed page with a reasonably sized font. If you find yourself running out of room, this is a good indication that you should encapsulate some of the work in a separate function.
What style guide do you use? ›
Tons of style guides exist across industries and genres, and new ones pop up frequently. Most writers will encounter four commonly used guides: AP style for journalism, Chicago style for publishing, APA style for scholarly writing and MLA style for scholarly citation (more on each of these below).
What is the R style language? ›
R is a high-level programming language used primarily for statistical computing and graphics. R does not have any well defined coding recommendations or de facto standards. This style guide provides some recommendations based on personal experience and expert opinions (see Additional Guides).
Where do I write R code? ›
The RStudio interface is simple. You type R code into the bottom line of the RStudio console pane and then click Enter to run it. The code you type is called a command, because it will command your computer to do something for you. The line you type it into is called the command line.
Can I write R in Vscode? ›
Once you have installed Visual Studio Code, you will want to install the R Extension. You can do this by clicking on the Extensions icon in the left sidebar and searching for “R”. You will need to add the languageserver package in R. You can do this by running the following code in the R console.
What is the ideal words per line? ›
To determine line length for optimum readability, a good guideline is between 9 and 12 words for unjustified text. Fewer words may cause the sentence structure to break up, and may also result in too many hyphenations.
What are the best practices for naming conventions in R? ›
Use only lowercase letters and numbers. Use underscores ( _ ) (so called snake case) to separate words within a name. Use names that are concise and meaningful (this is not easy!). Generally, variable names should be nouns and function names should be verbs.
What is the ideal character per line for readability? ›
45 to 80 characters (per line) is the ideal line length for text on websites. The final number of characters per line depends on the font, but so long as your content is falling within the above parameters, you're making it as easy as possible for visitors to read your content.
The Google Python Style Guide defines the coding standards used at Google. This style guide has two parts, one focusing on language rules (conventions and coding standards) and the other on style rules (aesthetic formatting issues).
How do I change what Google looks like? ›
From the list of search engines, select the search engine you want to edit. Click Overview and scroll down to Look and Feel. Click on "All look and feel settings". Under Theme, select the Theme you want to use from the drop down list.
What is a style in Google? ›
If you have the structure of your document with its titles, headings, and normal text, click "Style" to add a finishing touch. The add-on will change the text font, size, formatting, spacing & alignment of each part according to the style set of your choice.
How many Google Local Guides are there? ›
There are currently more than 150 million Google Maps Local Guides posting reviews, adding photos, answering questions, and suggesting updates.
