[Gretl-users] vertical matrix concatenation (was matrix declaration error)

Allin Cottrell cottrell at wfu.edu
Wed Jan 31 09:42:28 EST 2007


On Wed, 31 Jan 2007, Ignacio Díaz-Emparanza wrote:

> El Martes, 30 de Enero de 2007 23:41, Allin Cottrell escribió:
>> Yes, I think that's a good idea.  Meanwhile, do we want a
>> temporary symbol for vertical concatenation, or just forget it for
>> now?
>
> My vote is for leaving the things as they are. I think it is not so
> problematic to use X = ( a' ~ b' )'

It's true, that does the job.  But a direct "X = a | b" would be 
more computationally efficient.  The version above involves n+1 
"unnecessary" transpositions when concatenating n matrices.  With 
small matrices and a simple script that hardly matters, but it 
could make an appreciable difference with large matrices in the 
context of an iteration.

Allin.


More information about the Gretl-users mailing list