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AW: st: question


From   "Martin Weiss" <martin.weiss1@gmx.de>
To   <statalist@hsphsun2.harvard.edu>
Subject   AW: st: question
Date   Tue, 3 Nov 2009 15:26:04 +0100

<> 

"No, this is because these numbers are going to HUGE..."


Weirdly though, it also happens when the result is "1.9944475"...


*************
clear*
set obs 10000
set seed 12345

gen x1=rnormal()
gen x2=rnormal() 
gen y=0.2+.03* x1+.01* x2 +rnormal()

reg y x?

di exp(_b[_cons]+_b[x2]*15.3)* /* 
*/ exp(e(rss)/e(df_r)/2)
nlcom exp(_b[_cons]+_b[x2]*15.3)* /* 
*/ exp(e(rss)/e(df_r)/2)
*************



HTH
Martin


-----Ursprüngliche Nachricht-----
Von: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Maarten buis
Gesendet: Dienstag, 3. November 2009 15:23
An: statalist@hsphsun2.harvard.edu
Betreff: Re: st: question

--- On Tue, 3/11/09, Tunga Kantarci wrote:
> I wish to calculate a figure where I call coefficient
> estimates and residuals sum of squares and degrees of
> freedom. All these quantities are from the stata
> estimation output. When I run the relevant command 
> -nlcom exp(_b[_cons]+_b[income]*15.3)*exp(e(rss)/e(df_r)/2)- 
>I get the error "could not calculate numerical derivative".
> This is perhaps because e(rss) and e(df_r) are not estimates.

No, this is because these numbers are going to HUGE, so huge
that in many cases a computer can't contain that number. This
to me suggest a conceptual error rather than a Stata error:
why do you want to do this?

-- Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------


      

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