HP 12c Platinum Reference Guide

Forecasting 89
12c platinum / 12C
RPN KEYSTROKES
DISPLAY
12c platinum
ALG KEYSTROKES
DISPLAY
:0
038, 45 0
:6
038, 45 6
z
039, 10
g(000
039,43,33,000
:2
040, 45 2
fs
+
041, 40
?6
042, 44 6
g(000
043,43,33,000
fs
REGISTERS
n: Unused i: Unused PV: Unused PMT: Unused
FV: Unused R
0
: α R
1
: 1-α R
2
: S
t-1
R
3
: T
t-1
R
4
: Σe
2
R
5
: D
t
R
6
: D
ˆ
t+1
R
7
-R
.4
: Unused
Program Instructions:
Selecting the "best" smoothing constant (α ):
1.
Key in the program and press fCLEARH.
RPN Mode:
2.
Key in the number 1 and press \.
3.
Key in the "trial " and press ?0-?1.
ALG Mode:
2.
Key in the number 1 and press -.
3.
Key in the "trial " and press ?0³?1.
4.
Key in the first historical value (X
1
) and press ?2.
5.
Key in the second historical value (X
2
) and press ?6t. The result is the error
between the forecast value
D
ˆ
(
t+1
) and the true value (X
t+1
).
6.
Press
t; the display shows the next forecast D
ˆ
(
t+2
).
7.
Optional: Press
:5 to display the smoothed estimate of current demand.
8. Continue steps 5 and 6 for X
3
, X
4
, ... X
n
until all historical values have been entered.
When doing step 5 merely key in the value and press
t (do not press ?6).
9.
Press
:4. This value represents the cumulative forecasting error (∑e
2
). Record the
value and the following additional values; press
:0 (α), :2 (smoothed average
S
t-1
), :3 (trend T
t-1
) and :6 (forecast D
ˆ
t+1
).
10.
Press
fCLEARH.
11. Repeat steps 2 through 10 until a "best" α is selected based on the lowest cumulative
forecasting error (Register 4).

HP 12c Platinum Specifications

General

Digits	10 digits
Battery type	CR2032
Type	Financial
Form factor	Pocket

Weight and Dimensions

Weight	110 g
Dimensions (WxDxH)	79 x 129 x 15 mm