HP 20S and HP 21S: Simple Logistic Regression
For the HP
Prime and TI-84 Plus CE versions, please click here: http://edspi31415.blogspot.com/2017/04/hp-prime-and-ti-84-plus-ce-simple.html
This program
attempts to fit a simple logistic curve of data (X, Y) to the equation:
y = 1/(A +
B*e^(-x))
By the
following transformations:
X’ =
e^(-X)
Y’ = 1/Y
And performing
linear regression analysis on X’ and Y’.
Note that the data point which includes Y = 0 is not allowed.
The keystrokes
for the HP 20S and HP 21S are slightly different. Each program will be shown separately.
Input:
Initialize the
data: XEQ A
For each data
point: x, [INPUT], y, XEQ B
Calculate the
parameters: XEQ C. B is shown first, then A.
HP 20S Program: Simple
Logistic Regression
|
STEP
|
CODE
|
KEY
|
|
01
|
61, 41, A
|
LBL A
|
|
02
|
61, 75
|
CLRΣ
|
|
03
|
61, 26
|
RTN
|
|
04
|
61, 41, B
|
LBL B
|
|
05
|
15
|
1/X
|
|
06
|
51, 31
|
SWAP
|
|
07
|
32
|
+/-
|
|
08
|
12
|
e^x
|
|
09
|
51, 31
|
SWAP
|
|
10
|
16
|
Σ+
|
|
11
|
61, 26
|
RTN
|
|
12
|
61, 41, C
|
LBL C
|
|
13
|
61,
16
|
m,
b
|
|
14
|
26
|
R/S
|
|
15
|
51, 31
|
SWAP
|
|
16
|
61, 26
|
RTN
|
HP 21S Program: Simple
Logistic Regression
|
STEP
|
CODE
|
KEY
|
|
01
|
61, 41, A
|
LBL A
|
|
02
|
61, 75
|
CLRΣ
|
|
03
|
61, 26
|
RTN
|
|
04
|
61, 41, B
|
LBL B
|
|
05
|
15
|
1/X
|
|
06
|
51, 31
|
SWAP
|
|
07
|
32
|
+/-
|
|
08
|
12
|
e^x
|
|
09
|
51, 31
|
SWAP
|
|
10
|
16
|
Σ+
|
|
11
|
61, 26
|
RTN
|
|
12
|
61, 41, C
|
LBL C
|
|
13
|
51,
14
|
m,
b
|
|
14
|
26
|
R/S
|
|
15
|
51, 31
|
SWAP
|
|
16
|
61, 26
|
RTN
|
Like the last
post (minimum and maximum), this is one of my favorite programs I have done
this year. I think the Wheatstone
circuit would also make the list.
Eddie
This blog is
property of Edward Shore, 2017