Thanks a lot!
________________________________
Cc: R help <r-help@r-project.org>
Sent: Tuesday, March 19, 2013 8:39 PM
Subject: Re: [R] How to subsetting data based on factor levels
levels(group)
#[1] "A" "C"
levels(group)=="A"
#[1] TRUE FALSE
a[,group=="A"]
# A AB
#[1,] 1 6
#[2,] 2 7
#[3,] 3 8
#[4,] 4 9
#[5,] 5 10
a[,group=="C"]
# C CD
#[1,] 11 16
#[2,] 12 17
#[3,] 13 18
#[4,] 14 19
#[5,] 15 20
a[,match(group,levels(group))==1]
# A AB
#[1,] 1 6
#[2,] 2 7
#[3,] 3 8
#[4,] 4 9
#[5,] 5 10
A.K.
----- Original Message -----
To: r-help <r-help@r-project.org>
Cc:
Sent: Tuesday, March 19, 2013 9:19 PM
Subject: [R] How to subsetting data based on factor levels
Here are the code and results
============
> a=matrix(1:20,5)
> a
[,1] [,2] [,3] [,4]
[1,] 1 6 11 16
[2,] 2 7 12 17
[3,] 3 8 13 18
[4,] 4 9 14 19
[5,] 5 10 15 20
> colnames(a)=c("A","AB","C","CD")
> a
A AB C CD
[1,] 1 6 11 16
[2,] 2 7 12 17
[3,] 3 8 13 18
[4,] 4 9 14 19
[5,] 5 10 15 20
> group=factor(substring(colnames(a),1,1))
> group
[1] A A C C
Levels: A C
> a[,levels(group)=="A"]
A C
[1,] 1 11
[2,] 2 12
[3,] 3 13
[4,] 4 14
[5,] 5 15
> a[,levels(group)=="C"]
AB CD
[1,] 6 16
[2,] 7 17
[3,] 8 18
[4,] 9 19
[5,] 10 20
==============
But, I was expect that:
a[,levels(group)=="A"]
A AB
[1,] 1 6
[2,] 2 7
[3,] 3 8
[4,] 4 9
[5,] 5 10
[[elided Yahoo spam]]
[[alternative HTML version deleted]]
______________________________________________
R-help@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.
[[alternative HTML version deleted]]
______________________________________________
R-help@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.
