Matrix Multiplication using Hash Object

[sai_ch]

Hi All,

Looking for optimal ways to multiply two matrices with out using IML. Is it possible to use Hash object to accomplish the task?

A =  1  3      B =  1   1         A*B = 7   7

        2 4              2   2                   10  10

Thanks

[Astounding · Accepted solution]

Hash objects would be a poor choice.  Two-dimensional arrays could work, however.

Within a SAS data set, there is no such construct as a matrix.  There are tons of variables.  So it would be up to you to track what dimensions to use for your matrices and what variables go where.  You could certainly code something along these lines:

array a {2,3} a1-a6;

array b {3,2} b1-b6;

array dotprod {2,2} dotprod1-dotprod4;

do i=1 to 2;

   do j=1 to 3;

    ** construct 2 dotprod elements here;

   end;

   do j=4 to 6;

    ** construct 2 more dotprod elements here;

   end;

end;

This would be "optimal" in the sense that it runs quickly.  But you still have to do a lot of the planning and thinking.