# Re: st: Questions about matrix operations

 From anirban basu To statalist@hsphsun2.harvard.edu Subject Re: st: Questions about matrix operations Date Mon, 17 Jun 2002 14:45:36 -0500 (CDT)

```Hi,

I think you want the -mat score- option...

mat bhat=e(b)
mat score xb=bhat

Remember, it will genenate a scalar for each observation. i.e. xb will be
a new variable containing values of x(i).b for observation (i).

Anirban

______________________________________
ANIRBAN BASU
Doctoral Fellow
Harris School of Public Policy Studies
University of Chicago
(312) 563 0907 (H)
________________________________________________________________

On Mon, 17 Jun 2002, Wolff wrote:

> Hey folks,
> I have a simple problem.  I have a regression with three variables.  I
> would like to create a new variable equal to the sum of the estimated
> coefficients times the variable values.  The coefficients are saved in
> the matrix e(b).  I would like to do something like newvar=e(b)'*[var1
> var2 var3].  Since e(b)' is 1X3 and the next matrix is 3X1, I thought it
> would generate a scalar.  Is there an easy way to accomplish this?
>
> Thanks,
> Eric
>
>
>
> Eric D. Wolff
> Carnegie-Mellon University
> Tech and Frew
> Pittsburgh, PA 15213
> (412) 268-2939 (office)
> (412) 268-6837 (fax)
> email: wolff@andrew.cmu.edu
>
>
> *
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> *   http://www.ats.ucla.edu/stat/stata/
>

*
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```