[R] Build a matrix from another matrix by specifying the indexes

Peter Alspach Peter.Alspach at plantandfood.co.nz
Tue Feb 2 21:16:09 CET 2010

Tena koe Anna

This sounds like merge to me.


HTH ....

Peter Alspach 

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of anna
> Sent: Wednesday, 3 February 2010 9:07 a.m.
> To: r-help at r-project.org
> Subject: [R] Build a matrix from another matrix by specifying 
> the indexes
> Hello R specialists,
> I have a base vector called vBase with 102 elements. I have 
> another vector
> vec1 which elements are only part of vBase but is shorter. I 
> transform vec1 so I get a vector with the same size as vBase 
> and with each common element on the same indexed row. If a 
> value is missing in vec1 then I put a Na like
> this:
>       vec1                vBase
> Amsterdam              Amsterdam
> Na                         Bruxelles
> Dublin                     Dublin 
> Frankfurt                 Frankfurt
> Paris                       Paris
> This is how I did it: vec1 <- vec1[match(vBase,vec1)] But 
> what I really want to is the same but on a matrix columns, 
> for example mat <- cbind( vec1, vec2 ,vec3) I found a way to 
> make a match on each column:
> indexes <- apply(mat, 2, match, x = vBase) It returns me the 
> indexes matrix but I don't know how each index column to each 
> mat column like I did for vec1 with vec1[]. Any idea?
> -----
> Anna Lippel
> --
> View this message in context: 
> http://n4.nabble.com/Build-a-matrix-from-another-matrix-by-spe
> cifying-the-indexes-tp1460326p1460326.html
> Sent from the R help mailing list archive at Nabble.com.
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