Re: [Gretl-users] vertical matrix concatenation (was matrix declaration error)
On Wed, 31 Jan 2007, Ignacio DÃaz-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.