On 2/14/09, Doug Stewart <dastew at sympatico.ca> wrote:
> I see some work was done on Z Transforms in 2007, but I can't find it now.
>
> I am using Maxima 5.13.0 in Ubuntu.
>
> How do I get it to work?
I recently worked on the z-transform stuff again and made some progress.
I've committed the z_transform.mac program and rtest_z_transform.mac
test script. You should be able to see them here:
http://maxima.cvs.sourceforge.net/maxima/maxima/share/contrib
They will be in the next release (due in April).
random example:
load (z_transform);
apply_z_transform (z_transform (1 + kron_delta (m, x), m, u));
=> 1/u^x+u/(u-1)
batch (rtest_z_transform, test);
=> (... lots o' stuff ...) 24/24 tests passed.
Hope this helps. I';ll be glad to hear any comments. There are
doubtless many more transform rules that can be implemented,
maybe we can get going on that. By the way, I'll recommend
getting the most recent version of Maxima (5.17.1).
best
Robert Dodier