On Sun, Jan 17, 2010 at 06:50:36AM +0100, Jaroslav Hajek wrote:
> On Sun, Jan 17, 2010 at 1:47 AM, orzech <
address@hidden> wrote:
> >
> > Hi,
> > I would like to get an invertible matrix in Octave but as integers matrix,
> > so:
> >
> > x = [9,15;19,2];
> > inv(x)
> >
> > and the result is:
> >
> > [-0.0074906, 0.0561798; 0.0711610, -0.0337079]
> >
> > but I would like to get [22,17;25,21] anyone knows how to convert this
> > result? Many thanks.
> >
>
> I don't understand:
> octave:7> [22,17;25,21] * [9,15;19,2]
> ans =
>
> 521 364
> 624 417
>
> this is clearly not remotely close to an inverse or its multiple.
I think orzech is calculating in the 26 residue class[1], i.e. Z/mZ with m=26.