Message-ID: <1342563463.59386.YahooMailNeo@web39403.mail.mud.yahoo.com>
Date: 2012-07-17T22:17:43Z
From: arun
Subject: Finding the column with the maximum value by row
In-Reply-To: <CALrjt79wcCALA-4se+rUXDeg5gVKuki_JjFwgGaxu=0=_WgntQ@mail.gmail.com>
Hi,
Try,
apply(a,1,which.max)
[1] 3 1 3
A.K.
----- Original Message -----
From: Christopher Desjardins <cddesjardins at gmail.com>
To: r-help at r-project.org
Cc:
Sent: Tuesday, July 17, 2012 6:03 PM
Subject: [R] Finding the column with the maximum value by row
Hi,
Let's say I have the following data:
> a=matrix(c(1,2,4,4,2,1,1,2,4),nrow=3,byrow=T)
> a
? ? [,1] [,2] [,3]
[1,]? ? 1? ? 2? ? 4
[2,]? ? 4? ? 2? ? 1
[3,]? ? 1? ? 2? ? 4
What syntax should I use to get R to tell me the column that corresponds to
the maximum value for each row?
For my example, I would like to get a vector that says 3, 1, 3 because the
maximum value for row 1 is in column 3, the maximum value for row 2 is in
column 1, and the maximum value for row 3 is in column 3.
Does that make sense?
Please cc me if you reply!
Chris
??? [[alternative HTML version deleted]]
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