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.
I would feel more confortable with the method minimum_distance having an
argument force (which default to False). The behavior would be that with
force=True, the computation is always done. What do you think?
Well, you could have posted about this ticket here, and/or cc
potential reviewers on the ticket.
On May 25, 2015 1:59 AM, "Vincent Delecroix" <20100.d...@gmail.com> wrote:
> In the current situation, Sage has an extra argument to initialize the minimum distance (curious but it is there). Since #18099, this argument is used to initialize the attribute _minimum_distance but then this attribute is completely ignored (since minimum_distance is now a cached_method and does not rely anymore on the attribute).
> So let me first say that before #18099, Sage was *not* computing the minimum distance. It only returned an integer that was stored as an attribute! So the timing used to be few micro seconds rather than few seconds.
This was introduced by me in #13090. I was working with lot of simulations of communication systems using modifications of well known linear codes and the first stumbling block was the very long time computing the minimum distance took.
Irrespective of how the linear codes are implemented, it would be immensely helpful if some basic stuff is fast. In my usage of linear codes I had come across the following issues:
* getting minimum distance of well known codes was very slow
* iterating through all codewords was very slow
* getting the n-th codeword in some sense of "n-th" was very slow
* decoding of codes was very slow. I am glad that the linear codes are becoming individual classes. That's how I handled decoding in my own work.
@lucas Please feel free to post in this group if you want feedback. I wasn't really free the past few months but I have a bit more time at hand now and will go through the tickets when I can.