HP 15c - Manual (Page 123)

Section 4: Using Matrix Operations 123
Keystrokes Display
+ 089- 40
l0 090- 45 0
´mA 091-42,23,11 Dimensions matrix A as
(p + 2) × (p + 1)
1 092- 1
- 093- 30
1 094- 1
´mC 095-42,23,13 Dimensions matrix C as p × 1.
lA 096- 45 11 Recalls q.
´>1 097-42,16, 1 Sets k = l = 1.
|n 098- 43 32
Labels used: A, B, C, and 1 through 5.
Registers used: R
0
, R
1
, and R
2
(p+2 and w)
Matrices used: A (working matrix) and C (parameter estimates).
Flags used: 0 and 8.
With this program stored, the HP-15C has enough memory to work with up to p = 4
parameters. If programs "A" and "C" are deleted, you can work with p = 5 parameters. In
either case, there is no limit to the number of rows that you can enter.
To use this program:
1. Press 2 ´m% to reserve registers R
0
through R
2
.
2. Press ´U to activate User mode.
3. Enter (p + 2) and (p + 1) into the stack, then press ´mA to dimension
matrix A. The dimensions depend on the number of parameters that you use, denoted
by p.
4. Press 0 O>A to initialize matrix A.
5. Enter the weight w
k
of the current row, then press A. The display should show
1.0000 to indicate that the program is ready for the first row element. (For ordinary
least-squares problems, use w
k
= 1 for each row.)
6. Enter the elements of the row m of matrix A by pressing
x
m1
¦x
m2
¦…x
mp
¦y
m
¦. After each element is entered, the display
should show the number of the next element to be entered. (If you make a mistake
while entering the elements, go back and repeat steps 5 and 6 for that row.
7. Press B to update the factorization to include the row entered in the previous two
steps