Re: [OctDev] new release?

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

I just returned from vacation and noticed that CVS contained several 
updates to the files in question in my previous mail below. I'm happy to 
report that cyclgen appears to work properly for the inputs that I 
tested. I also tested cyclpoly and discovered that when compared to the 
ouput of the same function in Matlab, the results are the same but 
appear in reverse order, i.e. fliplr(cyclgen(255,247)) is equivalent to 
cyclgen(255,247) in Matlab. Thank you for all the work you have done in 
fixing these functions.

-Quentin



Quentin Spencer wrote:

> 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
>