Message-ID: <C57EBD7A-721D-4F72-B818-ABB482075F9E@comcast.net>
Date: 2008-12-13T14:50:39Z
From: David Winsemius
Subject: Extract rows from data frame based on row names from anotherdata frame
In-Reply-To: <200812112121.DLW63445@md0.mail.umd.edu>
Matching row names was the request.
# continuing with your example:
rownames(d1)<- letters[1:5]
rownames(d2)<- letters[3:7]
# and then for rownames of d1 that are also in rownames of d2:
# for the full rows ...
d1[row.names(d1) %in% row.names(d2),]
# or for just the names:
rownames(d1)[row.names(d1) %in% row.names(d2)]
--
David Winsemius
On Dec 11, 2008, at 4:21 PM, Daniel Malter wrote:
> Hi
>
> #Create data and data frames
> x=rnorm(5,0,1)
> y=rnorm(5,0,1)
> z=rnorm(5,0,1)
> d1=data.frame(x,y)
> d2=data.frame(y,z)
>
> #which variable name in d2 is a variable name in d1?
> names(d2[names(d2)%in%names(d1)]) # it's y
>
> #give me the columns of d2 that have variable names
> #that are also variable names in d1
>
> d2[names(d2)==names(d2[names(d2)%in%names(d1)])]
>
> #check
> d2$y
>
> Cheers,
> Daniel
>
>
> -------------------------
> cuncta stricte discussurus
> -------------------------
>
> -----Urspr?ngliche Nachricht-----
> Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] Im
> Auftrag von Wade Wall
> Gesendet: Thursday, December 11, 2008 3:59 PM
> An: r-help at stat.math.ethz.ch
> Betreff: [R] Extract rows from data frame based on row names from
> anotherdata frame
>
> Hi all,
>
> Is there a function to extract row names from a data frame based on
> row
> names from another data frame? I can write a loop function to do
> this, but
> this may be inefficient in terms of processing.
>
> thanks for any information,
>
> Wade
>
> ______________________________________________
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> ______________________________________________
> 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.