Re: [OctDev] new release?

[David B. <Dav...@mo...>]

I believe it probably still works correctly for small values of n, since
that was all I tested previously. Oh, well it looks like the method I used
to create the generator matrix is too naive...

Cheers
David

According to Quentin Spencer <qsp...@ie...> (on 06/18/04):
> OK, I tested your changes to the coding stuff and this is what I found:
> 
> bchpoly appears to give correct results for the cases I tested
> cyclgen(255,bchpoly(255,247)) gives the correct result
> cyclgen(255,bchpoly(255,239)) gives a matrix that is correct in the
> first 8x8 submatrix, and zeros everywhere else !?
> cyclpoly gives a vector containing all zeros for every input I tried.
> 
> Well, I guess there's at least some progress since one case worked. I'm
> sorry the news isn't better.
> 
> -Quentin
> 
> 
> David Bateman wrote:
> 
> >According to Quentin Spencer <qsp...@ie...> (on 06/16/04):
> > 
> >
> >>David,
> >>
> >>Thanks. The updates fixed hammgen. However, now I've found another bug. 
> >>I don't know if it was there all along or newly introduced. The 
> >>following command should produce the 16x255 parity check matrix for a 
> >>BCH 2-error correcting code:
> >>cyclgen(255,bchpoly(255,239))
> >>
> >>The result instead is:
> >>error: cyclgen: generator polynomial does not produce cyclic code
> >>
> >>I verified the resulting polynomial against MATLAB and they matched.
> >>   
> >>
> >
> >Ok, I'm a bit draft. The test I added checks if the polynomial is primitive
> >rather than just irreducible. I'd previously tried to adapt this test in
> >the older code, but failed.
> >
> >So I went back to the basic implementation of dividing x^n-1 by the
> >polynomial and checking that there was no remainder. It appears to
> >work correctly for you test case now. Though maybe you want to give
> >it a bit more testing.. Changes checked into the CVS
> >
> >Regards
> >David
> >
> > 
> >
> 
> 
> 
> 
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David Bateman                                Dav...@mo...
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