On Wed, Jan 21, 2009 at 1:25 PM, Paul Zimmermann
<[email protected]> wrote:
>
>       Hi,
>
> on http://www.loria.fr/~zimmerma/exemple40.sage you can find a 500x360
> integer matrix for which computing the Hermite Normal Form takes about
> 10 times longer in Sage than in Magma:
>
> sage: C
> 500 x 360 dense matrix over Integer Ring
> sage: time A=C.hermite_form()
> CPU times: user 22.91 s, sys: 0.09 s, total: 23.01 s
> Wall time: 23.02 s
>
> (it takes 2.440s with Magma on the same machine)
>
> Is there a faster way to compute a HNF in Sage?

Not yet.   Sage has *very* fast HNF for random dense matrices.   Your
matrix is very non-random and sparse, where the algorithm in sage
doesn't apply.  I haven't thought about the sparse case.

>  Does IML do that?

No.

 -- William

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