RPN with HP 15C & DM32: Min, Max, Midrange, Log Mean
Introduction
These set of programs calculates four statistics:
(1) Minimum
(2) Maximum
(3) Midrange = (minimum + maximum) / 2
(4) Log Mean, using the maximum and minimum points. The general formula is:
log mean(T1, T2) = (T2 – T1) / ln(T2 / T1)
The program also enters data points into the statistics registers, allowing for one-variable statistics to be performed.
DM 32 Code
Initialization: LBL I
I01 LBL I
I02 STO M
I03 STO N
I04 CLΣ
I05 Σ+
I06 RTN
Enter data, maximum on the Y stack, minimum on the X stack: LBL T
T01 LBL T
T02 STO J
T03 Σ+
T04 RCL M
T05 RCL J
T06 x<y?
T07 STO M
T08 RCL N
T09 RCL J
T10 x>y?
T11 STO N
T12 RCL N
T13 RCL M
T14 STOP
T15 GTO T
Midrange: LBL M
M01 LBL M
M02 RCL N
M03 RCL+ M
M04 2
M05 ÷
M06 RTN
Log-Mean – Use maximum and minimum to determine the log-mean: LBL L
L01 LBL L
L02 RCL N
L03 RCL- M
L04 RCL N
L05 RCL÷ M
L06 LN
L07 ÷
L08 RTN
Variables Used:
J: temporary value
M = minimum
N = maximum
Instructions:
Step 1: Enter the first point and start the process by executing label I.
Step 2: Enter subsequent points and execute label T. The minimum is shown on the X stack, and the maximum is shown on the Y stack.
Step 3: To calculate the midrange, execute label M. To calculate the log mean, execute label L.
HP 15C Code
Initialization: LBL A
001 |
42, 21, 11 |
LBL A |
002 |
44, 0 |
STO 0 |
003 |
44, 8 |
STO 8 |
004 |
44, 9 |
STO 9 |
005 |
44, 32 |
CLΣ |
006 |
45, 0 |
RCL 0 |
007 |
49 |
Σ+ |
008 |
43, 32 |
RTN |
Enter data, maximum on the Y stack, minimum on the X stack: LBL B
009 |
42, 21, 12 |
LBL B |
010 |
44, 0 |
STO 0 |
011 |
49 |
Σ+ |
012 |
45, 8 |
RCL 8 |
013 |
45, 0 |
RCL 0 |
014 |
43, 30, 8 |
TEST 8, x<y? |
015 |
44, 8 |
STO 8 |
016 |
45, 9 |
RCL 9 |
017 |
45, 0 |
RCL 0 |
018 |
43, 30, 7 |
TEST 7, x>y? |
019 |
44, 9 |
STO 9 |
020 |
45, 9 |
RCL 9 |
021 |
45, 8 |
RCL 8 |
022 |
31 |
R/S |
023 |
22, 12 |
GTO B |
Midrange: LBL C
024 |
42, 21, 13 |
LBL C |
025 |
45, 8 |
RCL 8 |
026 |
45, 40, 9 |
RCL + 9 |
027 |
2 |
2 |
028 |
10 |
÷ |
029 |
43, 32 |
RTN |
Log-Mean – Use maximum and minimum to determine the log-mean: LBL D
030 |
42, 21, 14 |
LBL D |
031 |
45, 9 |
RCL 9 |
032 |
45, 30, 8 |
RCL - 8 |
033 |
45, 9 |
RCL 9 |
034 |
45, 10, 8 |
RCL ÷ 8 |
035 |
43, 12 |
LN |
036 |
10 |
÷ |
037 |
43, 32 |
RTN |
Variables Used:
R0: temporary value
R8 = minimum
R9 = maximum
Statistical variables used (as default):
R2 = n
R3 = Σx
R4 = Σx^2
R5 = Σy
R6 = Σy^2
R7 = Σxy
Instructions:
Step 1: Enter the first point and start the process by executing label A.
Step 2: Enter subsequent points and execute label B. The minimum is shown on the X stack, and the maximum is shown on the Y stack.
Step 3: To calculate the midrange, execute label C. To calculate the log mean, execute label D.
Examples
Example 1:
0.2322 |
0.8252 |
0.8005 |
0.9262 |
Maximum: 0.9262
Minimum: 0.2322
Midrange: 0.5792
Log Mean: 0.5016
Example 2:
96 |
54 |
29 |
64 |
48 |
27 |
Maximum: 96
Minimum: 27
Midrange: 61.5
Log Mean: 54.3945
Sources
Volk, William. Engineering Statistics With A Programmable Calculator. McGraw-Hill Book Company: New York. 1982. pp. 8-9. ISBN 0-07-067552-X.
“Logarithmic Mean” Wikipedia. Last updated September 30, 2024. https://en.wikipedia.org/wiki/Logarithmic_mean. Last retrieved October 10, 2024.
Until next time,
Eddie
All original content copyright, © 2011-2025. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.
