#13771: Canonical Forms and Automorphism Groups of linear codes
-------------------------------------------------+-------------------------
       Reporter:  tfeulner                       |        Owner:  wdj
           Type:  enhancement                    |       Status:
       Priority:  major                          |  needs_review
      Component:  coding theory                  |    Milestone:  sage-5.13
       Keywords:  linear code, canonical form,   |   Resolution:
  automorphism group, semilinear equivalent      |    Merged in:
        Authors:  Thomas Feulner                 |    Reviewers:
Report Upstream:  N/A                            |  Work issues:
         Branch:                                 |       Commit:
   Dependencies:  #13726                         |     Stopgaps:
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Comment (by darij):

 Just saw this mentioned on sage-combinat-devel; sorry I can't be of any
 actual help, so I thought I'll just drop a few remarks...

 tfeulner: Given that you reference your thesis in the code, wouldn't it
 make sense to put it online on, say, arXiv?

 I don't understand what `_cyclic_shift` is supposed to do. What is being
 cycled? If you want to get a cyclic permutation, why the `+ 1`'s in:
 {{{
         122             x[p[i - 1]] = p[i] + 1
         123         x[p[len(p) - 1]] = p[0] + 1
 }}}

 "quadrupel" should be "quadruple".

 {{{
         45          For every `i \in \{0, \ldots, n-1\}`
         46          there is a group `G^{(i)}` and a surjective group
 homomorphism `f^{(i)}: G
         47          \rightarrow G^{(i)}` such that `(f^{(i)}, \Pi^{(i)})`
 is a homomorphism of
         48          group actions where `\Pi^{(i)}: X^n \rightarrow X` is
 the projection to
         49          the `i`-th coordinate.
 }}}
 Isn't this a rather complicated way to say that the action of `G \rtimes
 \{id\}` on `X^n` is given by a direct product of several `G`-sets `X` ? I
 agree that the above is more precise, but can't you at least get rid of
 the `G^{(i)}` by assuming it to be `G` right away?

--
Ticket URL: <http://trac.sagemath.org/ticket/13771#comment:19>
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