Re: [OctDev] new release?

[Quentin S. <qsp...@ie...>]

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
>
>  
>