[R] updating columns using other column as reference

[Henrique Dallazuanna]

Milton,

Try this:

myDF[grep("k", names(myDF))] <- sapply(myDF[grep("k", names(myDF))],
function(idx)myDF$namesp[idx])


On Mon, Oct 19, 2009 at 2:03 PM, milton ruser <milton.ruser at gmail.com> wrote:
> Dear R-gurus,
>
> Just supose I have a dara.frame that looks like
>
> myDF<-read.table(stdin(),head=T,sep=",")
> codID,namesp,k1,k2,k3,k4
> 1,spA,2,5,6,3
> 2,spB,4,5,4,6
> 3,spC,2,1,5,6
> 4,spC,5,4,3,2
> 5,spD,1,2,3,4
> 6,spE,2,4,3,1
>
> I need to update the columns k1-k4 with the namesp, but
> considering the math between Kx and codID.
>
> My desired output must looks like:
>
> codID,namesp,k1,k2,k3,k4
> 1,spA,spB,spD,spE,spC
> 2,spB,...
> 3,spC,...
> 4,spC,...
> 5,spD,...
> 6,spE,...
>
> Any help are welcome.
>
> cheers
>
> milton
>
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>
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-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O