In constructing block matrixes one often needs this. For example,
to construct the state variable equations for a electric circuit,
there are 2 matrixes containing link resistors and branch resistors.
If there are no link resistors, then that block is empty, but it still
has to conform to other matrixes in the block.
I suppose the behavior of empty matrixes could be changed, so that
they could conform in either direction.
Stavros Macrakis wrote:
> You are right that Maxima supports matrix([],[]) -- a matrix of 0
> columns and 2 rows -- but has no representation for a matrix of 2
> columns and 0 rows. This is inconsistent, I agree. Is there some
> compelling reason, though, to support it?
>
> -s