I know it does not look very good - using the same column names to mean different things in different data frames, but here you go: --8<---------------cut here---------------start------------->8---> x <- data.frame(a=c(1,2,3),b=c(4,5,6)) > y <- data.frame(b=c(1,2),a=c("a","b")) > merge(x,y,by.x="a",by.y="b",all.x=TRUE,suffixes=c("","y"))a b a 1 1 4 a 2 2 5 b 3 3 6 <NA> Warning message: In merge.data.frame(x, y, by.x = "a", by.y = "b", all.x = TRUE) : column name 'a' is duplicated in the result --8<---------------cut here---------------end--------------->8--- why is the suffixes argument ignored? I mean, I expected that the second "a" to be "a.y". (when I omit suffixes, the result is the same). Thanks. -- Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000 http://www.childpsy.net/ http://palestinefacts.org http://honestreporting.com http://truepeace.org http://openvotingconsortium.org My name is Deja Vu. Have we met before?
On 2012-10-07 08:34, Sam Steingold wrote:> I know it does not look very good - using the same column names to mean > different things in different data frames, but here you go: > --8<---------------cut here---------------start------------->8--- >> x <- data.frame(a=c(1,2,3),b=c(4,5,6)) >> y <- data.frame(b=c(1,2),a=c("a","b")) >> merge(x,y,by.x="a",by.y="b",all.x=TRUE,suffixes=c("","y")) > a b a > 1 1 4 a > 2 2 5 b > 3 3 6 <NA> > Warning message: > In merge.data.frame(x, y, by.x = "a", by.y = "b", all.x = TRUE) : > column name 'a' is duplicated in the result > --8<---------------cut here---------------end--------------->8--- > why is the suffixes argument ignored? > I mean, I expected that the second "a" to be "a.y".The 'suffixes' argument refers to _non-by_ names only (as per ?merge). Peter Ehlers> (when I omit suffixes, the result is the same). > Thanks. >
Hi,
Though, this does give the result you wanted when the column names are the same.
?y1<-y
?colnames(y1)<-c("a","b")
merge(x,y1,by="a",all=TRUE,suffixes=c("",".y"))
#? a b? b.y
#1 1 4??? a
#2 2 5??? b
#3 3 6 <NA>
A.K.
----- Original Message -----
From: Sam Steingold <sds at gnu.org>
To: r-help at r-project.org
Cc:
Sent: Sunday, October 7, 2012 11:34 AM
Subject: [R] a merge() problem
I know it does not look very good - using the same column names to mean
different things in different data frames, but here you go:
--8<---------------cut
here---------------start------------->8---> x <- data.frame(a=c(1,2,3),b=c(4,5,6))
> y <- data.frame(b=c(1,2),a=c("a","b"))
>
merge(x,y,by.x="a",by.y="b",all.x=TRUE,suffixes=c("","y"))
? a b? ? a
1 1 4? ? a
2 2 5? ? b
3 3 6 <NA>
Warning message:
In merge.data.frame(x, y, by.x = "a", by.y = "b", all.x =
TRUE) :
? column name 'a' is duplicated in the result
--8<---------------cut here---------------end--------------->8---
why is the suffixes argument ignored?
I mean, I expected that the second "a" to be "a.y".
(when I omit suffixes, the result is the same).
Thanks.
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
http://www.childpsy.net/ http://palestinefacts.org http://honestreporting.com
http://truepeace.org http://openvotingconsortium.org
My name is Deja Vu. Have we met before?
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