re: st: using vector notation to simplify coding

[Kit Baum <baum@bc.edu>]

<>
Dan said

Thanks for the clarification, Kit. I am having trouble shaking the SAS  
mindset on this stuff, and your note, along with Michael's, have  
helped a lot. I "get" the mata approach, being a old Fortran guy ...it  
feels like a cumbersome solution in Stata right now, but I am sure  
that is a transitory feeling.

Actually it is a very elegant solution, taking advantage of the  
concept of 'view matrices' in Stata. Surely as another old Fortran guy  
you remember the EQUIVALENCE statement. That's what is happening with  
a view matrix (real programmers don't need no steenken pointers!) so  
that changes in Mata to the contents of the matrix (Y in my code)  
actually changes the contents of the Stata variables that populate the  
matrix. That is very powerful (and naturally can be dangerous if  
misunderstood).

See http://ideas.repec.org/p/boc/dsug09/06.html
(and ITSP, which illustrates this at greater length)

Cheers
Kit

Kit Baum   |   Boston College Economics & DIW Berlin   |   http://ideas.repec.org/e/pba1.html
                              An Introduction to Stata Programming   
|   http://www.stata-press.com/books/isp.html
   An Introduction to Modern Econometrics Using Stata  |   http://www.stata-press.com/books/imeus.html



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