What is your preferred style for naming variables in R? [closed]

Answer 1

Underscores all the way! Contrary to popular opinion, there are a number of functions in base R that use underscores. Run grep("^[^\\.]*$", apropos("_"), value = T) to see them all.

I use the official Hadley style of coding ;)

Answer 2

Good previous answers so just a little to add here:

• underscores are really annoying for ESS users; given that ESS is pretty widely used you won't see many underscores in code authored by ESS users (and that set includes a bunch of R Core as well as CRAN authors, excptions like Hadley notwithstanding);

• dots are evil too because they can get mixed up in simple method dispatch; I believe I once read comments to this effect on one of the R list: dots are a historical artifact and no longer encouraged;

• so we have a clear winner still standing in the last round: camelCase. I am also not sure if I really agree with the assertion of 'lacking precendent in the R community'.

And yes: pragmatism and consistency trump dogma. So whatever works and is used by colleagues and co-authors. After all, we still have white-space and braces to argue about :)

Answer 3

This comes down to personal preference, but I follow the google style guide because it's consistent with the style of the core team. I have yet to see an underscore in a variable in base R.

Answer 4

Usually I rename my variables using a ix of underscores and a mixed capitalization (camelCase). Simple variables are naming using underscores, example:

PSOE_votes -> number of votes for the PSOE (political group of Spain).

PSOE_states -> Categorical, indicates the state where PSOE wins {Aragon, Andalucia, ...)

PSOE_political_force -> Categorial, indicates the position between political groups of PSOE {first, second, third)

PSOE_07 -> Union of PSOE_votes + PSOE_states + PSOE_political_force at 2007 (header -> votes, states, position)

If my variable is a result of to applied function in one/two Variables I using a mixed capitalization.

Example:

positionXstates <- xtabs(~states+position, PSOE_07)

Answer 5

I have a preference for mixedCapitals.

But I often use periods to indicate what the variable type is:

mixedCapitals.mat is a matrix. mixedCapitals.lm is a linear model. mixedCapitals.lst is a list object.

and so on.

Answer 6

As others have mentioned, underscores will screw up a lot of folks. No, it's not verboten but it isn't particularly common either.

Using dots as a separator gets a little hairy with S3 classes and the like.

In my experience, it seems like a lot of the high muckity mucks of R prefer the use of camelCase, with some dot usage and a smattering of underscores.