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

Re: st: Matrix Algebra


From   "Michael Blasnik" <michael.blasnik@verizon.net>
To   <statalist@hsphsun2.harvard.edu>
Subject   Re: st: Matrix Algebra
Date   Mon, 7 Oct 2002 07:49:06 -0400

Just one more post on this ...

"Alfonso Miranda" noted that :

> Having a second look I found that
>
> mymat = 12.4869*H
>
>
> Thus, Stata is giving me the correct matrix except for a constant. I
> believe Stata is doing some sort of standarization when unsing the
> variable res2 as an analytical weigh, isn't it ?. Could any one explain
> me how does it works?

If you examine the output from mat accum you see:

> >  .matrix accum H = a1 a2 a3 [aw=res2], noc
> > (sum of wgt is   2.4974e+03)
> > (obs=200)
> >
 your constant of 12.49 is simply the ratio of the sum of the weights to the
number of obs :

2497.4 / 200 = 12.49

Michael Blasnik


*
*   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