NX Nastran DMAP Programmer's Guide - Kxcad.net

1409
SMPYAD
Matrix series multiply and add
2. The matrices are postmultiplied together from right to left; i.e., the first product
calculated is the product of matrix n-1 and matrix n. This implies that all purged
inputs must be to the right. If the transpose flag is set for the last unpurged matrix,
it is ignored without warning.
3. If the input matrices are incommensurate (for example, if the number of columns
in A is not equal to the number of rows in B) or incompatible, then the User Fatal
Message 5423 “ATTEMPT TO MULTIPLY INCOMPATIBLE MATRICES” is
issued.
4. The method used by this module is the same as for the MPYAD module except in
case of a triple product, where [B] and [F] are symmetric and [A] = [C] and TA = 1;
i.e., [X] = [A] T [B][A] ± [F], then a method that is more efficient than two equivalent
MPYAD operations will be employed. See Example 3. However, two equivalent
MPYAD operations will be selected automatically if two MPYADS are more
efficient. (Two MPYADs can be forced by setting system cell 129 to 1, with
PUTSYS(1,129) specified just before the SMPYAD module.)
5. If any of the matrices involved in the product do not exist, then the module does
not create any output.
Examples:
1. Compute [X] = [A] [B] T [C] - [F]
SMPYAD A,B,C,,,F/X/3/1/-1/0/0/1 $
2. Compute [Z] = -[U] T [V] T [W] T [X] T [Y]
SMPYAD U,V,W,X,Y,/Z/5/-1/0/0/1/1/1/1 $
3. Compute
[ φ]
T [ M]
[ φ]
SMPYAD PHI,MAA,PHI, ,,/X/3////1////6 $