Figure out what version of R a function was introduced in

Question

Is there a way to find out what version of R certain functions were introduced in? For example regmatches is a useful function but it is fairly new and I believe it was int

Answer 1

Even easier than Dirk's solution is to use R's news function:

> newsDB <- news()
> news(grepl("regmatches",Text), db=newsDB)
Changes in version 2.14.0:

NEW FEATURES

    o   New function regmatches() for extracting or replacing matched or
         non-matched substrings from match data obtained by regexpr(),
         gregexpr() and regexec().

---

As of R-3.3.0, news will launch via the HTML help system if it is available. You can suppress it via the print.news_db method:

> print(news(grepl("news",Text), db=newsDB), doBrowse=FALSE)
Changes in version 3.3.0:

NEW FEATURES

    o   news() now displays R and package news files within the HTML help
         system if it is available.  If no news file is found, a visible
         NULL is returned to the console.

Answer 2

You can use the SVN repository:

edd@max:~/svn/r-devel/src/library/base/man$ svn log regmatches.Rd 
------------------------------------------------------------------------
r57006 | hornik | 2011-09-14 14:04:21 -0500 (Wed, 14 Sep 2011) | 1 line

Improve example.
------------------------------------------------------------------------
r56997 | hornik | 2011-09-12 15:16:03 -0500 (Mon, 12 Sep 2011) | 1 line

Document regmatches replacement function.
------------------------------------------------------------------------
r56893 | hornik | 2011-09-02 05:31:01 -0500 (Fri, 02 Sep 2011) | 1 line

Add first version of regmatches replacement function.
------------------------------------------------------------------------
r56818 | hornik | 2011-08-29 02:49:17 -0500 (Mon, 29 Aug 2011) | 1 line

Spelling.
------------------------------------------------------------------------
r56752 | hornik | 2011-08-18 01:40:07 -0500 (Thu, 18 Aug 2011) | 1 line

Add regmatches().
------------------------------------------------------------------------
edd@max:~/svn/r-devel/src/library/base/man$ 

I applied svn log to the manual page as I didn't immediately see the R file the function is defined in; the command would work the same way there...