From mdowle at mdowle.plus.com  Wed Feb 16 19:36:38 2011
From: mdowle at mdowle.plus.com (Matthew Dowle)
Date: Wed, 16 Feb 2011 18:36:38 +0000
Subject: [Rd] method="radix" in sort.list() isn't actually a radix sort
Message-ID: <ijh5fm$837$1@dough.gmane.org>

Dear list,

Were you aware that, strictly speaking, do_radixsort in sort.c actually
implements a counting sort, not a radix sort ?

http://en.wikipedia.org/wiki/Counting_sort

It it was a radix sort it wouldn't need the 100,000 range restriction.

Clearly the method argument can't be changed (now) from "radix" to
"counting", but perhaps a note could be added to the .Rd ?

According to Wikipedia, Harold H. Seward created both counting and
radix sorting in 1954, and they are distinctly different.

I did a grep through all R source for the keyword "radix" in case this
was already documented. A google search and rseek.org search didn't
return results for "counting sort" in the R context.

There appears to be scope to add (true) radix sorting to R then, that
doesn't have the 100,000 range restriction.  Is there any interest in that?

Matthew



[Rd] method="radix" in sort.list() isn't actually a radix sort
Matthew Dowle