Dear Alberto,
Try this:
# colnames and rownames
cn <- colnames(a)
rn <- rownames(a)
# the index
ind <- which(a==0, arr = TRUE)
# the result
data.frame( res = apply(ind, 1, function(x)
paste(rn[x[1]],",", cn[x[2]], sep ="")
)
)
# res
# 1 A1,F1
# 2 A3,F1
# 3 A2,F2
# 4 A3,F3
See ?which, ?apply and ?paste for more information.
HTH,
Jorge
On Wed, Jul 15, 2009 at 7:15 PM, Alberto Lora M <[email protected]>wrote:
> Dear sir,
>
> I have a matrix like
>
> a<-matrix(c(0,2,0,4,0,6,5,8,0),nrow=3)
> colnames(a)<-c("F1","F2","F3")
> rownames(a)<-c("A1","A2","A3")
> a
>
> F1 F2 F3
> A1 0 4 5
> A2 2 0 8
> A3 0 6 0
>
> I want to extract all pairs (rownames, columnames) from which the value in
> the matrix is 0
>
> The result should be something like this
>
> A1, F1
> A2, F2
> A3, F1
> A3, F3
>
> how it is possible?
>
> thanks for your help....
>
> Best Regards
>
> Alberto
>
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>
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> and provide commented, minimal, self-contained, reproducible code.
>
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and provide commented, minimal, self-contained, reproducible code.
