Section 12: Calculating with Matrices 155
For ÷, the matrix specified in the X-register is replaced by its LU
decomposition. The ÷ function calculates X
−1
Y using a more direct
method than does ⁄ and *, giving the result faster and with
improved accuracy.
Example: Using matrices A and B from the previous example, calculate
C = A
T
B.
A =
1 2 3
4 5 9
and B =
1 3 5
7 9 17
Keystrokes Display
l > A
A 2 3
Recalls descriptor for
matrix A.
l > B
b 2 3
Recalls descriptor for
matrix B into X-register,
moving matrix A
descriptor into Y-register.
´ < C
b 2 3
Designates matrix C as
result matrix.
´ > 5
C 3 3
Calculates A
T
B and stores
result in matrix C, which is
redimensioned to 3 × 3.
The result, matrix C, is
C =
29 39 73
37 51 95
66 90 168
.