Could someone please help me out?
I have a matrix A={1 1,1 2,2 1,2 2,2 3,3 1}. I would like to create a block diagonal matrix (B) such that B={1 1 0 0 0 0, 1 2 0 0 0 0, 0 0 2 1 0 0, 0 0 2 2 0 0, 0 0 2 3 0 0, 0 0 0 0 3 1}. I know of the block function but it does not work here (in its basic form at least). How can I do this in IML? Is it possible without looping because the number of rows in A can get very large (millions or more)?
Lots of thanks in advance for your help.
George