Applications; Constructing An Identity Matrix; One-Step Residual Correction - HP -15C Advanced Functions Handbook

Section 4: Using Matrix Operations
119
Applications
The following programs illustrate how you can use matrix
operations to solve many types of advanced problems.
Constructing an Identity Matrix
This program creates an identity matrix I
n
in the matrix whose
descriptor is in the Index register. The program assumes that the
matrix is already dimensioned to n X n. Execute the program using
|GSB| 8. The final matrix will have 1's for all diagonal elements and
O's for all other elements.
Keystrokes
|EEX|
[fllUSERHSTOlRiyi
Display
000-
001-42,
002-42
003-42,
004-
005-
006-43,
007-
008-43,
009-
01 Ou
011-
012-
21, 8
16, 1
21, 9
45 0
45 1
30, 6
43 35
30, 5
26
44 24
22 9
43 32
Program mode.
Sets i=j= 1.
Tests iV jr.
Tests i = 7.
Sets element to 1 if i =j.
Skips next step at last
element.
Run mode.
Labels used: 8 and 9.
Registers used: R
0
, RI, and Index register.
One-Step Residual Correction
The following program solves the system of equations AX — B for
X, then performs one stage iterative refinement to improve the
solution. The program uses four matrices: