06-03-2017, 05:30 PM
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
HP 21S Program: Simple Logistic Regression
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
Code:
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 RTNHP 21S Program: Simple Logistic Regression
Code:
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