[R] matching matrix columns to a vector

Jagat.K.Sheth at wellsfargo.com Jagat.K.Sheth at wellsfargo.com
Mon Nov 24 17:59:43 CET 2008

How about which(colSums(t-v) == 0) ?

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of Salas, Andria Kay
Sent: Monday, November 24, 2008 10:04 AM
To: r-help at r-project.org
Subject: [R] matching matrix columns to a vector

I need help with (hopefully) just one more thing.  I have been fussing
with this for quite some time and have decided just to give up and ask!
I want to match a column in a matrix to a vector.  I found a "which"
command that I thought would be helpful as it does the following:

> g=c(1,5,3,2,7)
> which(g==5)
[1] 2

As the above gave which placement in the g vector corresponded to 5 (the
second place), I need this command to give me which column in a matrix
matches to a vector.

This is just a toy example of what I am trying to do:
> t=matrix(1:12,3,4)

This does not work, and with my "real" matrices and vectors, I was
getting outputs that did not make sense.  These examples are more to
give an idea of what I am aiming to accomplish.

Thank you for all the help!!
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