finding elements in an array

[Carlisle Thacker <thacker@aoml.noaa.gov>]

Suppose you have two vectors, which contain row and column indices of
some elements of an array.  Is there a good way to find the
corresponding elements?

For example:

> test <- matrix(1:20, ncol=4)
> test.i <- c(1,3,5)
> test.j <- c(4,2,2)

Is there a better way to get this answer?
> diag(test[test.i,test.j])
[1] 16  8 10

Thanks,

Carlisle


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* William Carlisle Thacker                             *
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