Message-ID: <06CE64A7-9BAC-11D7-B8A0-0005026E2B43@vanderkogel.net>
Date: 2003-06-11T01:28:38Z
From: Jonck van der Kogel
Subject: Multiple match function?
Hi all,
I have (yet another) question about a function in R. What I would like
to do is test for the presence of a certain value in a vector, and have
the positions that this value is at returned to me.
For example, let's say I have a vector:
x <- c(1,1,2,2,3,3,4,4)
Now I would like a function that would return positions 3 and 4 should
I test for the value "2". Or 5 and 6 should I test for "3".
Could someone please tell me how I should do this? The "match" function
only returns the first position that a value is found at. Of course I
could write my own function that loops through the vector and tests for
the presence of each value manually but it seems likely that a function
that does this is already present in R. No need to re-invent the wheel
:-)
Thanks very much, Jonck