Extract matrix column values by matrix column name

by

Yes. But place your “test” after the comma if you want the column…

> A <- matrix(sample(1:12,12,T),ncol=4)

> rownames(A) <- letters[1:3]

> colnames(A) <- letters[11:14]
> A[,"l"]
 a  b  c 
 6 10  1

see also help(Extract)

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