#19422: A new structure for Punctured Codes
-------------------------------------+-------------------------------------
       Reporter:  dlucas             |        Owner:
           Type:  enhancement        |       Status:  needs_review
       Priority:  major              |    Milestone:  sage-6.10
      Component:  coding theory      |   Resolution:
       Keywords:                     |    Merged in:
        Authors:  David Lucas        |    Reviewers:
Report Upstream:  N/A                |  Work issues:
         Branch:                     |       Commit:
  u/dlucas/punctured_codes           |  ca859cbf3e6b86ccc218d6e51813ae45b9babb34
   Dependencies:                     |     Stopgaps:
-------------------------------------+-------------------------------------

Old description:

> This ticket proposes a new implementation for punctured codes.
>
> It contains:
>
> - a new code class, `PuncturedCode`
>
> - a dedicated encoder to compute the generator matrix of a Punctured
> Code.
>
> This new structure presents the following advantages:
>
> - it keeps track of the code it comes from. If one punctures a code A,
> the punctured code he gets will remember it comes from A.
>
> - This allows to perform several operations, like encoding or picking a
> random element without constructing the generator matrix for the
> punctured code, thus saving time and memory.
>
> - Later on, it will also allow to decode words using a decoder over the
> original code of the punctured code.

New description:

 This ticket proposes a new implementation for punctured codes.

 It contains:

 - a new code class, `PuncturedCode`

 - a dedicated encoder to compute the generator matrix of a Punctured Code.

 - a dedicate decoder which uses the original code to correct errors

 This new structure presents the following advantages:

 - it keeps track of the code it comes from. If one punctures a code A, the
 punctured code one gets will remember it comes from A.

 - This allows to perform several operations, like encoding or picking a
 random element without constructing the generator matrix for the punctured
 code, thus saving time and memory.

 - because it keeps track of the original code, it's possible to get a
 structured representation of the punctured code, e.g. if one punctures a
 GRS code and asks for the structured representation of the punctured code
 one got, a GRS code will be returned.

--

Comment (by dlucas):

 A few updates on this ticket:

 - it's now under the latest beta
 - as we now have the structure for decoders in Sage, I added a dedicated
 decoder for punctured codes
 - as we now have GRS codes in Sage, which still are GRS codes after
 puncturing, I introduced a mechanism which allows one to get the most
 specific representation possible for a punctured code, based on the
 original code.

 This is still open for review.

--
Ticket URL: <http://trac.sagemath.org/ticket/19422#comment:10>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica, 
and MATLAB

-- 
You received this message because you are subscribed to the Google Groups 
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.

Reply via email to