Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: RE: nl-function log4-formula


From   Nick Cox <[email protected]>
To   "'[email protected]'" <[email protected]>
Subject   st: RE: nl-function log4-formula
Date   Wed, 16 Nov 2011 10:36:08 +0000

I don't know, but tucking the -if- condition inside the parentheses looks a bit odd. Try moving it outside. 

-nl- is a command, not a function. 

Nick 
[email protected] 

Jennyfer Wolf

I am working with the nl-function and with the logistic function model log 4.
Could somebody please explain me why I do not get the same outout if I type:

1. nl log4: VAR1 VAR2 if VAR3=="xxx"

and

2. nl(VAR1={b0}+{b1}/(1+exp(-{b2}*(VAR2-{b3}))) if VAR3=="xxx")

Actually 1. should just be an abbreviation of 2.?
If I run command 1, I get estimates for b0, b1, b2, b3, if I run
command 2 I only get an estimate for b0 and b1-b3 are 0.

Could somebody explain how to write the formula "in full" (like in
2.), to get the same results as in the first formula.


*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index