On Tue, Dec 30, 2014 at 2:18 AM, William Stein <wst...@gmail.com> wrote: > ---------- Forwarded message ---------- > From: Aneta Buraczyńska <an.buraczyn...@gmail.com> > Date: Mon, Dec 29, 2014 at 11:03 PM > Subject: error in Sage > To: William Stein <wst...@gmail.com> > > > Dear Mr William Stein, > > I am writing with request for contact to Sage creators or reading my > problem. In module sage.crypto.boolean_function there is a function: > walsh_hadamard_transform(). I think this function gives wrong results. > For instance for function f defined by truth table (1, 0, 0, 0, 0, 1, > 1, 1) sage gives vector (0, 0, 0, 0, -4, 4, 4, 4) as a result, but the > correct value is (0, 0, 0, 0, 4, -4, -4, -4). All functions that I > verified have in sage error result due to incorrect signs. On appendix
I agree that the signs are incorrect, based on the definition I usually use. Possibly there is a definition out there somewhere with that sign change? There are different normalizing conventions for Fourier transforms, so it seems reasonable to me that there are different ones for the Walsh-Hadamard transform as well. > I send a document with the calculations showing my statement. > > I will be grateful for help in this problem. > > Yours Sincerely, > > Aneta Buraczyńska > > > > > -- > William Stein > Professor of Mathematics > University of Washington > http://wstein.org > > -- > You received this message because you are subscribed to the Google Groups > "sage-support" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-support+unsubscr...@googlegroups.com. > To post to this group, send email to sage-support@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
