HP 15c - Manual (Page 100)

100 Section 4: Using Matrix Operations
100
matrix A + ΔA represented by the LU decomposition. It can be zero only if the product's
magnitude becomes smaller than 10
−99
(underflow).
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 × n. Execute the
program using G8. The final matrix will have l's for all diagonal elements and 0's for all
other elements.
Keystrokes Display
|¥
Program mode.
´CLEARM 000-
´b8 001-42,21, 8
´>1 002-42,16, 1 Sets i = j = 1.
´b9 003-42,21, 9
l0 004- 45 0
l1 005- 45 1
|T6 006-43,30, 6 Tests i ≠ j.
|` 007- 43,35
|T5 008-43,30, 5 Tests i = j.
“ 009- 26 Sets elements to 1 if i = j.
´UO%
´U 010u 44 24 Skips next step at last element.
t9 011- 22 9
|n 012- 43 32
|¥ Run mode.
Labels used: 8 and 9.
Registers used: R
0
, R
1
, and Index register.