On Fri, Dec 05, 2008 at 10:21:32AM +0100, Marco Maso wrote: > When you talk about maximum grade 31 for a x86 and 63 for a x86_64 what > are you referring? > If you are referring to the grade of the generator polynomial I'm stuck > and I couldn't do anything without heavily moddifying the code (if I've > understood well), if you are talking about the galois field > "cardinality" this would be not a problem. A field of 2^63 - 1 elements > is more than enough to represent what I'm trying to do...but probably > we are in the first case, isn't it? > > I say this beacuse if we are in the second case your reply > isn't so related to my question about the two errors...
As the Galois field is represented as a set on "int" values the maximum Galois feild that can be represented is GF(2^31), which was a primitive polynomial of order 32. This is in fact the "grade" I was talking about. It seems the grade you are talking about is the order of the BCH generator polynomial, which is constructed from the cyclotomic cosets of the galois field (cf the cosets function). I'd have to look up the exact process to construct the BCH generator polynomial from the cosets, but if I remember correctly the order of the BCH generator polynomial is always less that the order of the primitive polynomial of the galois field, and so yes the limit on the order or "grade" of the BCH generator polynomial in the octave-foreg package is 31.. Have you looked at the PARI/GP package that might be what you are looking for to work with such large generator polynomials? Check http://pari.math.u-bordeaux.fr/ Regards David ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
