Hi,
I have a problem trying to rank across the rows of a matrix where in each row I
might not want to include every element. For example, I have a 3x3 matrix (in
actual fact much bigger) called fred (it's better than test!) :
fred =
[,1] [,2] [,3]
[1,] 0.09616424 -1.194590 0.2640956
[2,] -0.35525355 1.500998 -0.1802140
[3,] 0.44401227 1.059076 0.7822802
and another matrix showing the elements I am interested in in each row:
in.fred =
[,1] [,2] [,3]
[1,] F T T
[2,] T T F
[3,] T F T
what I want to generate is a matrix of the ranks of the rows
comp.rank
[,1] [,2] [,3]
[1,] NA 1 2
[2,] 1 2 NA
[3,] 1 NA 2
The best I've come up with is:
for (i in 1:3)
{
comp.rank [i, in.fred [i,]] = rank (fred [i, in.fred [i,]])
}
I'm sure that there must be a better way than this but I can't see it. Note
that I can't rely on there being the same number of trues in each line of the
in.fred matrix. Any help gratefully received.
Regards,
David Jessop
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