Re: [R] matching matrix columns to a vector

From: <Jagat.K.Sheth_at_wellsfargo.com>
Date: Mon, 24 Nov 2008 10:59:43 -0600

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)
>v=c(1,2,3)
>which(t[,j]==v)

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!!



R-help_at_r-project.org mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.

R-help_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Mon 24 Nov 2008 - 17:03:21 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 25 Nov 2008 - 07:30:29 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive