Matrix inversion tool

[Matan Ziv-Av]

On Sat, 8 Aug 2015, Omer Zak wrote:

> What happens if you use the regular matrix inversion tool which works on
> real numbers?
> (after rejecting, as singular over Z2, matrices whose determinant modulo
> 2 is different from 1)

This will work if the inverse only has integer entries. It may also work 
if your algorithm returns rational numbers, but will not work with 
floating point numbers (there are no reals in a computer). You cannot 
faithfully convert 1.1234 to an element of Z_2.

> On Sat, 2015-08-08 at 20:31 +0300, Shachar Shemesh wrote:
>> Hi all,
>>
>> I'm looking for a tool/code to invert a matrix. So far, this sounds
>> trivial. I have one special requirement. I did not think it was too
>> special, except I could not find anywhere that supplied it.
>>
>> I want the matrix to be over a different field (i.e. - not the real
>> numbers). In my particular case, I want it to be over Z2 (zero and
>> one).
>>
>> So far, I have failed to find such a tool. If anyone knows how to do
>> it, please let me know, as the alternative is writing one myself,
>> which is something I REALLY don't want to do without a good reason.

You can use GAP ( http://www.gap-system.org/ ).

>

-- 
Matan.