Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: logistic regression: changing a coefficient


From   "Schonlau, Matthias" <[email protected]>
To   <[email protected]>
Subject   st: RE: logistic regression: changing a coefficient
Date   Tue, 15 Feb 2005 09:03:09 -0800

Good point. My example failed to say that I have about 100 explanatory variables. This line 
   gen xb2 = _b[_cons] + -.35*mpg + _b[weight]*weight
is cumbersome in my case - but I' ll think about whether I can automate it in a loop.

Thanks for your suggestion!

Matt 
 


Date: Mon, 14 Feb 2005 21:41:12 -0600
From: "Scott Merryman" <[email protected]>
Subject: st: RE: logistic regression: changing  a coefficient

How about something like this:

. sysuse auto
(1978 Automobile Data)

. qui logit fore mpg weight

. gen xb2 = _b[_cons] + -.35*mpg + _b[weight]*weight

. gen prob2 = exp(xb2)/(1 + exp(xb2))


Scott


> -----Original Message-----
> From: [email protected] [mailto:owner-
> [email protected]] On Behalf Of Schonlau, Matthias
> Sent: Monday, February 14, 2005 7:00 PM
> To: [email protected]
> Cc: Schonlau, Matthias
> Subject: st: logistic regression: changing a coefficient
> 
> Dear stata listers:
> 
> Is it possible to change a coefficient after running logistic regression
> and run a predict statement?
> 
> e.g.
> 
> logistic y x1 x2 x3
> matrix A=e(b)
> /* change the value of the first  coefficient, e.g. to lower limit of CI
> */
> matrix A[1,1]=0.5
> replace e(b)=A   /* this line does not work */
> predict pred
> 
> Thanks ,
> 
> matt
> 
> 
> 
> 
> 
> Matthias Schonlau
> Statistician, RAND
> http://www.rand.org/methodology/stat/members/matt/


Matthias Schonlau
Statistician, RAND 
http://www.rand.org/methodology/stat/members/matt/

--------------------

This email message is for the sole use of the intended recipient(s) and
may contain privileged information. Any unauthorized review, use,
disclosure or distribution is prohibited. If you are not the intended
recipient, please contact the sender by reply email and destroy all copies
of the original message.




*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index