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

From   "Wu, Xun" <>
To   "''" <>
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.


-----Original Message-----
From: Weihua Guan [] 
Sent: Thursday, July 10, 2003 12:25 PM
Subject: st: Re: RE: Re: Initial values not feasible and -ufrom()- option. 

--"Wu, Xun" <> wrote,

> Thanks for Scott's information and David's method, I solve the initial
> problem in Frontier with the -from()- option . 
> 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()-.
-from()-, -ufrom()- only takes a matrix.  The syntax is like:

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

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

Weihua Guan <> 
Stata Corp.

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