[R] Matrix

[Duncan Murdoch]

On 16/07/2016 6:25 PM, Ashta wrote:
 > Hi all,
 >
 > I have a large square matrix (60 x 60)  and found it hard to
 > visualize. Is it possible to change it  as shown below?
 >
 > Sample example (3 x 3)
 >
 >     A   B   C
 > A  3   4   5
 > B  4   7   8
 > C  5   8   9
 >
 > Desired output
 > A A  3
 > A B  4
 > A C  5
 > B B  7
 > B C  8
 > C C  9

Yes, use matrix indexing.  I don't think the 3600 values are going to be 
very easy to read, but here's how to produce them:

m <- matrix(1:3600, 60, 60)
indices <- expand.grid(row = 1:60, col = 1:60)
cbind(indices$row, indices$col, m[as.matrix(indices)])

Duncan Murdoch