Kevin Acres on Thu, 24 Dec 2009 12:34:13 +0100

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

```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.
```
```

```