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Unread 23-03-2015, 22:21
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Re: 2015 OPR After Week Four Events

Quote:
Originally Posted by Ed Law View Post
The part that takes the longest time is A(T) * A.
Did you try making [A], [A'], and [N] integer instead of floating point? If VBA supports integer matrix multiplication that would probably substantially reduce the computation time. Use the native word size of your machine for the integer size. Your machine is probably 64bit word size? So make the elements of each matrix 64-bit integers.

Quote:
Originally Posted by Ed Law View Post
I have to solve A x = b 6 times
Once you've created [N]=[A'][A] you can use that [N] matrix to solve for all 6 components at once.

[N][x]=[d]

If you make [d] a 6-column matrix instead of a vector you can solve it once and get a 6-column matrix [x] with all 6 solutions.


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