Which functions in R base call internal code?

September 14, 2010

(This article was first published on 4D Pie Charts » R, and kindly contributed to R-bloggers)

In a recent question on Stack Overflow about speeding up group-by operations, Marek wondered which functions called .Internal code (and consequently were fast). I was surprised to see that there appears to be no built-in way to check whether or not this is the case (though is.primitive is available for primitive functions).

Writing such a function is quite straight forward. We simply examine the contents of the function body, and serach for the string “.Internal” within it.

callsInternalCode <- function(fn)
+++if(!require(stringr)) stop("stringr package required")
+++any(str_detect(capture.output(body(fn)), ".Internal"))

You can retrieve all the function in the base package with this one-liner taken from an example on the Filter help page.

funs <- Filter(is.function, sapply(ls(baseenv()), get, baseenv()))

Now getting the list of functions that call internal code is easy.

names(funs)[sapply(funs, callsInternalCode)]
[1] "abbreviate" "agrep"
[3] "all.names" "all.vars"
[5] "anyDuplicated.default" "aperm"

Tagged: internal, r

To leave a comment for the author, please follow the link and comment on their blog: 4D Pie Charts » R.

R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...

If you got this far, why not subscribe for updates from the site? Choose your flavor: e-mail, twitter, RSS, or facebook...

Tags: ,

Comments are closed.

Search R-bloggers


Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)