Bill Allombert on Wed, 23 Sep 2009 19:44:29 +0200 |
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Re: matkerint versus matsnf |
On Wed, Sep 23, 2009 at 06:55:07PM +0200, Jeroen Demeyer wrote: > Hello pari-dev, > > If I want to compute a Z-basis of the kernel of a matrix, the most > obvious GP function would be matkerint(). However, that does a > LLL-reduction which is not needed for my application. > The kernel of an integral matrix can also be found using matsnf(). In > many cases, matsnf is faster if the matrix has more columns than rows > (more unknowns than relations). This is almost exactly what matkerint(,2) does, apart for the final reduction... However this is still very surprising. What kind of matrix is that ? > Considering this, I think that it makes sense to add a flag to > matkerint() indicating that matsnf should be used. Why not instead add a flag to matkerint so that it does not perform the final LLL reduction ? Cheers, Bill.