Dear r-helpers,
I have a very simple question. Suppose my data is like
id=c(rep(1,2),rep(2,2))
b=c(2,3,4,5)
m=cbind(id,b)
m
id b
[1,] 1 2
[2,] 1 3
[3,] 2 4
[4,] 2 5
I wish to select the first observation for each id. That is, I want to
quickly select two rows:
id b
1 2
2 4
only. how
Try the duplicated() function. As in
m[!duplicated(id), ]
-tgs
On Wed, Apr 21, 2010 at 10:17 PM, gallon li gallon...@gmail.com wrote:
Dear r-helpers,
I have a very simple question. Suppose my data is like
id=c(rep(1,2),rep(2,2))
b=c(2,3,4,5)
m=cbind(id,b)
m
id b
[1,] 1 2
discussurus
-
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
Behalf Of gallon li
Sent: Wednesday, April 21, 2010 10:18 PM
To: r-help
Subject: [R] how to select the first observation only?
Dear r-helpers,
I have a very simple
-Original Message-
From: r-help-boun...@r-project.org
[mailto:r-help-boun...@r-project.org] On Behalf Of gallon li
Sent: Wednesday, April 21, 2010 7:18 PM
To: r-help
Subject: [R] how to select the first observation only?
Dear r-helpers,
I have a very simple question. Suppose
On Apr 21, 2010, at 10:17 PM, gallon li wrote:
Dear r-helpers,
I have a very simple question. Suppose my data is like
id=c(rep(1,2),rep(2,2))
b=c(2,3,4,5)
m=cbind(id,b)
m
id b
[1,] 1 2
[2,] 1 3
[3,] 2 4
[4,] 2 5
I wish to select the first observation for each id. That is, I want
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