(35S) Linearized S-Curve (Logistic Curve) Regression

[Dieter]

(03-12-2018 02:37 PM)gerry_in_polo Wrote:  I know but I want to see all the variables. The HP-35s allows only one letter per variable. They can be easily removed from the program if you want to. The STOP was added so you can see the data counter progress. Again you can remove it.

Fine.

(03-12-2018 02:37 PM)gerry_in_polo Wrote:  e^(-b*T) is a typographical error, it is e^(-c*T) in the program. The program listing itself is correct, I have run it several times on various data.

Gerardo, the S program cannot be correct as it has a jump to line S004 at the end. But such a line does not exist: in the listing line S003 is directly followed by S005.
So could you please check again and compare the listing in your post with the original program?

I still think that there is a line missing. Please take a look at this part of the code:

S005 INPUT S
S006 RCL F
S007 ÷
S008 1
S009 -
S010 LN

Since S is less than F the quotient S/F is < 1, and this minus 1 is negative. So the program tries to calculate the logarithm of a negative number – which cannot be correct.

Dieter