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
.
17
9
7
5
3
1
9
5
4
3
2
1
and
B
A
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
168
90
66
95
51
37
73
39
29
C
.
Summary of Contents for HP-15C
Page 1: ...HP 15C Owner s Handbook HP Part Number 00015 90001 Edition 2 4 Sep 2011 ...
Page 17: ...Part l HP 15C Fundamentals ...
Page 64: ......
Page 65: ...Part ll HP 15C Programming ...
Page 118: ...118 ...
