Re: How to implement equivalent of magma NullSpace in Pari/GP

[Kevin Acres <research@research-systems.com>]

Hi Bill,

Thanks for getting back on this.  I tried matker and it returns [;] 
and I'm not sure why as yet.

Also I missed a few rows off of the input in my first post. The 
correct 9 rows are:

[0, 1, 0, 0, 1, 0, 0, 0]
[0, 0, 1, 0, 0, 1, 0, 0]
[1, 0, 1, 0, 0, 0, 0, 0]
[0, 0, 0, 1, 0, 0, 1, 0]
[1, 0, 1, 0, 0, 0, 1, 0]
[1, 1, 0, 0, 0, 0, 0, 1]
[0, 1, 1, 0, 0, 0, 0, 1]
[0, 1, 1, 0, 0, 0, 0, 0]
[0, 0, 1, 0, 0, 1, 0, 0]

Best Regards,

Kevin.


At 09:40 PM 24/12/2009, Bill Allombert wrote:
> On Thu, Dec 24, 2009 at 08:33:41PM +1100, Kevin Acres wrote:
> > Hi,
> >
> > I'm trying to implement an equivalent of the Magma NullSpace() function.
>
> In PARI, this is called matker().
>
> > For example I'd like:
> >
> > [0 0 0 1 0 0 1 0]
> > [1 0 1 0 0 0 1 0]
> > [1 1 0 0 0 0 0 1]
> > [0 1 1 0 0 0 0 1]
> > [0 1 1 0 0 0 0 0]
> > [0 0 1 0 0 1 0 0]
> >
> > to return
> >
> > [0 1 0 0 0 0 0 0 1]
> > [0 0 1 0 0 1 1 0 0]
>
> Really ?  If you want to compute the kernel over Z/2Z then you should do
> matker(M*Mod(1,2)).
>
> Cheers,
> Bill.