On Sun, May 24, 2015 at 12:05 PM, Dima Pasechnik <dimp...@gmail.com> wrote: > > > On Saturday, 23 May 2015 22:36:10 UTC+1, vdelecroix wrote: >> >> On 23/05/15 12:53, Dima Pasechnik wrote: >> > please review #18480 that fixes the corner case >> >> Thanks for the fix Dima. >> >> >> For r > 5 it seems to hang interminably, while back in >> >> November/December I could do r = 7 in a few seconds, and >> >> do r = 10 without waiting too long. > > > this sounds very weird that minimum distance of a code of length 127 and > dimension 120 (this is for r=7) can be done in few seconds > using the quite brute force algorithm, that would call GAP's > AClosestVectorCombinationsMatFFEVecFFECoords > (see http://gap-system.org/Manuals/doc/ref/chap23.html#X82E5987E81487D18 for > the description) > that chases all the linear combinations of i vectors, for i = 1..122 (in > this case). >
Once you show that d!=1 and d!=2 (which can be done rather quickly in the binary case), all GAP needs to do is find 1 codeword of weight 3 in the kernel of the check matrix H. It doesn't seem that weird to me that such a vector can be found quickly. > Probably the GAP part was buggy before and didn't return the correct results > in general > (I vaguely recall there were reports of this code in GAP being buggy) > > Dima > > -- > You received this message because you are subscribed to the Google Groups > "sage-coding-theory" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-coding-theory+unsubscr...@googlegroups.com. > To post to this group, send email to sage-coding-the...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sage-coding-theory/ae42acec-45b7-4c6f-b818-2e07c4b342c4%40googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
