From maintainers-request at octave dot org Thu Jul  8 07:57:35 2004
Subject: Re: Help with [] for defined types
From: Andy Adler <adler at site dot uottawa dot ca>
To: David Bateman <David dot Bateman at motorola dot com>
cc: Paul Kienzle <pkienzle at users dot sourceforge dot net>,         <octave-maintainers@bevo.che.wisc.edu>
Date: Thu, 8 Jul 2004 08:55:55 -0400 (EDT)

On Thu, 8 Jul 2004, David Bateman wrote:

> What I suggest is that this is implemented as
>
> 	cat(cat(sparse(),full()), galois())
>
> with the proviso on memory you discuss below. The first cat would promote the
> sparse matrix to a full() as defined by the function
>
> NDArray concat (const Sparse& ra, const NDArray& rb, Array<int>& ra_idx)
>
> and the second similarly to a Galois type as
>
> galois concat (const NDArray& ra, const galois& rb, Array<int>& ra_idx)

David,

Just to be pedantic, Matlab defines [sparse(),full()] as sparse.
This makes sense in most cases, consider
    [sparse( eye(1000) ) , ones(1000,1)];

I don't think this impacts the rest of the discussion.

Andy