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

st: RE: Re: RE: Re: Initial values not feasible and -ufrom()- option.


From   "Wu, Xun" <WuX@wharton.upenn.edu>
To   "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu>
Subject   st: RE: Re: RE: Re: Initial values not feasible and -ufrom()- option.
Date   Thu, 10 Jul 2003 13:03:34 -0400

Thanks very much for Weihua's advice. 

I did try to delete "copy", but then I got the message " ufrom() must
specify a 1 x 31 matrix". Like I said in the last email, I followed David's
method and created a 1*30 matrix, but why -ufrom()- asked for a 1*31 matrix?

It is like, for instance, David created a 1*5 matrix of initial values, but
-ufrom()- asked for a 1*6 matrix.

Best
Xun

-----Original Message-----
From: Weihua Guan [mailto:wguan@stata.com] 
Sent: Thursday, July 10, 2003 12:25 PM
To: statalist@hsphsun2.harvard.edu
Subject: st: Re: RE: Re: Initial values not feasible and -ufrom()- option. 

--"Wu, Xun" <WuX@wharton.upenn.edu> wrote,

> Thanks for Scott's information and David's method, I solve the initial
value
> problem in Frontier with the -from()- option . 
> 
> http://www.stata.com/statalist/archive/2003-05/msg00650.html
> 
> However, when I was trying to fit a truncated-normal model, I still have a
> problem with option -ufrom()-.
> 
> I follow David Drucker's method to feed my own initial values:
> 1. Run OLS
> 2. matrix b0 = e(b), ln(e(rmse)^2), .1
> 3. I add option to the frontier command: distribution(tnormal) ufrom(b0,
> copy)
> 
> However, I always got a message "ufrom() must specify a matrix".
> 
> Is there anything different with -ufrom()- option?

The -ufrom()- option is a little different from the regular -from()-.
Unlike
-from()-, -ufrom()- only takes a matrix.  The syntax is like:

. frontier ..., ufrom(matname) ...

Xun should not specify ", copy" in his command. 


Weihua Guan <wguan@stata.com> 
Stata Corp.

*
*   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/
*
*   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 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index