Opened 21 months ago
Closed 17 months ago
#28073 closed enhancement (fixed)
Abstract Code Class
Reported by:  ghemes4  Owned by:  ghemes4 

Priority:  major  Milestone:  sage9.0 
Component:  coding theory  Keywords:  gsoc19 
Cc:  dimpase, jsrn, caruso, ghAdurand8  Merged in:  
Authors:  Marketa Slukova  Reviewers:  Dima Pasechnik, Durand Amaury 
Report Upstream:  N/A  Work issues:  
Branch:  4dbc878 (Commits, GitHub, GitLab)  Commit:  4dbc8789f4ef1e173987df7ba6e13769eacff2ac 
Dependencies:  #27634  Stopgaps: 
Description (last modified by )
AbstractLinearCode
is at the moment the most abstract representation of codes in Sage. This makes it very difficult to implement nonlinear codes and also codes with a metric different than Hamming.
We propose to create AbstractCode
class that will contain metricagnostic methods, as well as the encoder/decoder framework. AbstractLinearCode
will derive from this class.
Change History (59)
comment:1 Changed 21 months ago by
 Cc dimpase jsrn added
 Component changed from PLEASE CHANGE to coding theory
 Description modified (diff)
 Owner changed from (none) to ghemes4
 Type changed from PLEASE CHANGE to enhancement
comment:2 Changed 21 months ago by
 Summary changed from Abstract Code to Abstract Code Class
comment:3 Changed 21 months ago by
 Branch set to u/emes4/abstract_code
comment:4 Changed 21 months ago by
 Branch changed from u/emes4/abstract_code to u/ghemes4/coding/abstract_code
 Commit set to ba4fc5394446919f9969b5df6bb5b4da82bf9876
comment:5 followup: ↓ 7 Changed 21 months ago by
you've checked in uncleanly merged/rebased things, e.g.
+>>>>>>> 4f44acd853... Fixed some dependencies. Category still set up wrong.
please look at
>>>>
,<<<<
, and====
markers in these files, clean them up.
comment:6 Changed 21 months ago by
 Commit changed from ba4fc5394446919f9969b5df6bb5b4da82bf9876 to e8edfebc20568c2173cc4d2e9306edcff42fa85b
Branch pushed to git repo; I updated commit sha1. New commits:
e8edfeb  Fixed unclean merge.

comment:7 in reply to: ↑ 5 Changed 21 months ago by
Replying to dimpase:
Sorry about that, it showed me the cleaned up file in my editor.
comment:8 Changed 21 months ago by
I created the class AbstractCode
and moved all the relevant methods from AbstractLinearCode
.
Originally, I had default_encoder
and default_decoder
parameters in the initialisation of AbstractCode
, however, I ran into an issue with dependencies  if I set a default_encoder
for AbstractLinearCode
, this would then be the default for all the codes inheriting from this. I am sure that this can be fixed, however maybe it makes sense for classes such as AbstractLinearCode
to not have default decoders/encoders?
Finally, one of the doc tests fails. I tried to set up the category stuff (Parent.__init__()
), but I don't think I did it correctly.
This is just a rough, first draft.
comment:9 Changed 21 months ago by
 Commit changed from e8edfebc20568c2173cc4d2e9306edcff42fa85b to 880aebb7258263aa73ac90763551aeccbce84c94
Branch pushed to git repo; I updated commit sha1. New commits:
880aebb  Fixed default decoder/encoder dependencies. Set to None by default.

comment:10 Changed 21 months ago by
 Keywords gsoc19 added
comment:11 Changed 20 months ago by
Thanks for working on this! I took a quick view over the new class, and it looks good. There are some copy/paste errors in the documentation where it refers to AbstractLinearCode
or "this linear code" etc., but that's small stuff.
More importantly, I am worried about how AbstractCode
should fit into the category framework. In particular, a nonlinear code is not necessarily a module. Also, some objects people call codes are not even inside some free module like R^n
for some ring R
, e.g. polyalphabetic codes like Chinese Remainder Codes or Polynomial Remainder codes, which are inside A_1 x A_2 x ... x A_n
for some rings A_i
. Really, the most general notion of a code is just a subset of some set, which isn't saying much.
Perhaps, as we're now talking of a really base class for all codes, AbstractCode
should therefore simply omit setting up anything in the category framework, leaving that to more concrete implementations. The task of AbstractCode
would then basically only consist of setting up the encoder/decoder framework, as well as providing the metric
method, which I like (I guess list()
is fine too). It shouldn't even have a length I guess?
In this case, I don't know whether AbstractCode
should somehow otherwise be made a parent in the category framework, or whether we should agree that this is a "contract" that subclasses have to do themselves.
Best, Johan
comment:12 Changed 20 months ago by
 Commit changed from 880aebb7258263aa73ac90763551aeccbce84c94 to d11560039839bb16a6d85d9e4ed674afdabfc299
Branch pushed to git repo; I updated commit sha1. New commits:
d115600  No category set up and base_field in AbstractCode. No encoder/decoder error msgs. Documentation and tests.

comment:13 Changed 20 months ago by
I made all the changes we discussed, namely:
The category framework is no longer set up in AbstractCode
. Instead of inheriting from Module
, it now inherits from Parent
. I tried a few things, e.g. SageObject
, Set
here and Parent
seemed to do the trick. I added some documentation hopefully instructing the user on how to set the category framework up.
I took base_field
away from the initiating parameters of AbstractCode
. This should be the only change in AbstractLinearCode
.
The decoder
and encoder
methods now instruct the user to add a decoder/encoder for the code if they try to use the encoder/decoder framework without having set these up. I added tests for these. If there are no default encoders/decoders, the methods decoders_available
and encoders_available
return an empty list. Let me know if all the checks for None
are correctly set up.
I extended the documentation and following the example of AbstractLinearCode
, added an example of how to use AbstractCode
to create a subclass.
A lot of the documentation overlaps with AbstractLinearCode
, however I don't think this is an issue.
comment:14 Changed 20 months ago by
please push your updates...
comment:15 Changed 20 months ago by
 Commit changed from d11560039839bb16a6d85d9e4ed674afdabfc299 to 487e9e2ce347f619114d52bb33e98ab042947dee
comment:16 Changed 20 months ago by
Added methods __iter__
and __contains__
to AbstractCode
instructing the user to override them.
Changed Encoder
and Decoder
class documentation to instruct the user to inherit from these when working with linear codes (over any metric).
comment:17 Changed 20 months ago by
 Commit changed from 487e9e2ce347f619114d52bb33e98ab042947dee to 40df01e3e1bc92c4d22ae9928f39c24d64117841
Branch pushed to git repo; I updated commit sha1. New commits:
40df01e  Finished up documentation.

comment:18 Changed 20 months ago by
 Status changed from new to needs_review
comment:19 Changed 20 months ago by
 Dependencies set to #28209
comment:20 Changed 20 months ago by
 Commit changed from 40df01e3e1bc92c4d22ae9928f39c24d64117841 to 01135cbfae1ff481ba243ca05eabf229e8c1432d
Branch pushed to git repo; I updated commit sha1. New commits:
01135cb  Merge branch 'develop' of git://trac.sagemath.org/sage into t/28073/abstract_code

comment:21 Changed 20 months ago by
 Dependencies #28209 deleted
comment:22 Changed 20 months ago by
 Status changed from needs_review to needs_work
This looks very promising! My comments may look long but they are not too heavy. Note: this is not a complete review, I didn't compile, run the code and build the documentation. I'm hoping Dima will do that :)
 Top of the class:
The only assumption we kept is that the code is enumerable.
change to
The abstract notion of "code" that is implicitly used for this class is any enumerable subset of a cartesian product `A_1 \times A_2 \times \ldots \times A_n
for some sets
A_i`. Note though that this class makes no attempt to directly represent the code in this fashion, allowing subclasses to make the appropriate choices. The notion of metric is also not mathematically enforced in any way, and is simply stored as a string value. ".
The line just after has a line break very early, doesn't it?
part of the framework category
>part of the category framework
any method that works on linear codes works for our
>coming from AbstractCode code
 The example in
AbstractCode.__init__
is not great, since it doesn't yield a working code class (it doesn't implement_list_
etc.). Can you make an small, but more meaningful example, e.g. the code consisting of the l words
{ 00...00, 10...00, 11...00, ... 11...10, 11...11 }
For this code, you could add a full working example with implementations of
_list_
,__iter__
,__contains__
.
The For #28209, the example could be expounded upon in a short thematic tutorial: adding an encoder/unencoder from the ring (ZZ mod (l+1)) into the code. The metric could be Hamming (though the code is of course quite bad), and that would allow attaching the LinearCodeNearestNeighbor? decoder, which actually works for any code under the Hamming metric.
That would be very nice documentation for anyone wanting to implement a new class of codes not fitting in linear/hamming codes.
 The example for
_repr_
and_latex_
is unnecessarily complicated becauseAbstractCode
does not need supplying encoders and decoders. Use instead the smaller example from e.g.__contains__
.
 In doc for
decode_to_code
anddecode_to_message
, the description ofword
should say "an element in the ambient space asself
". The code might not be vectorial in the classical sense.
 For
decoder()
andencoder()
, the exception thrown should be aNotImplementedError
and the message could perhaps be "No encoder [resp. decoder] implemented for this code".
 In doc for
encode
, then the description ofword
should say "an element of a message space of the code". The message space might not be vectorial. The note after the INPUT block is not appropriate anymore and should just be removed.
 At this abstraction there's virtually no service we could put on an Encoder or
Decoder class which would justify having an AbstractEncoder? or
AbstractDecoder?, I think. In a strongly typed OOP language, like Java, we
would of course have to have such a thing, but I believe in Python and
SageMath in particular, the convention is not to have needless abstract
classes. Therefore your oneline doc changes to
encoder.py
anddecoder.py
are spoton: that's all the change we'll have for those files.
However, we are left with something of a documentation problem. For where do we document the precise interface requirements of an encoder and a decoder assumed by the framework in AbstractCode?? I think the best place for this is a (not too long) discussion at the top of the file
abstract_code.py
, i.e. just after "Any class inheriting ... can use the encode/decode framework". Here we can describe what that is, and what is meant and promised by an encoder/decoder.
I am OK with having a relatively short description of the purpose, and just mentioning the methods an encoder must have (
encode
,__call__
which is simplyencode
,unencode
,message_space
andcode
), and similarly for a decoder. And then pointing toEncoder
andDecoder
as examples.
Best, Johan
comment:23 Changed 19 months ago by
I'd like to wait for above to be implemented (at least in part) before doing my own review.
comment:24 Changed 19 months ago by
 Commit changed from 01135cbfae1ff481ba243ca05eabf229e8c1432d to 9608a237aeabcaf56416bc26475a6b3c0433e6c0
comment:25 followup: ↓ 26 Changed 19 months ago by
I implemented all the changes that Johan suggested.
One comment: In the new example in AbstractCode.__init__
, I didn't make it a part of the category framework, partially because I was unsure as to which category to choose.
comment:26 in reply to: ↑ 25 ; followup: ↓ 28 Changed 19 months ago by
Replying to ghemes4:
I implemented all the changes that Johan suggested.
You are fast! :)
One comment: In the new example in
AbstractCode.__init__
, I didn't make it a part of the category framework, partially because I was unsure as to which category to choose.
Putting it in the category framework would be great, but I think it is fine as it is. I'm happy with the example :)
One new comment I thought of: AbstractLinearCode
used to inherit from Module
as well as being injected into the category framework under Modules
. Now it inherits from AbstractCode
which, of course, does not inherit from Module
. My concern is whether some functionality from Module
might now have gotten lost?
I haven't checked out your ticket and compiled, but this is the list of methods I get with dir(C)
on a freshly created LinearCode
C
on Sage 8.8.rc3:
['CartesianProduct', 'Element', 'Hom', '__cached_methods', '__call__', '__class__', '__contains__', '__delattr__', '__dict__', '__dir__', '__div__', '__doc__', '__eq__', '__format__', '__gens_dict', '__getattribute__', '__getitem__', '__getstate__', '__hash__', '__init__', '__init_extra__', '__iter__', '__len__', '__make_element_class__', '__module__', '__mul__', '__ne__', '__new__', '__nonzero__', '__pari__', '__pyx_vtable__', '__rdiv__', '__reduce__', '__reduce_ex__', '__repr__', '__rmul__', '__setattr__', '__setstate__', '__sizeof__', '__slots__', '__str__', '__subclasshook__', '__temporarily_change_names', '_abstract_element_class', '_an_element_', '_apply_module_endomorphism', '_apply_module_morphism', '_ascii_art_', '_assign_names', '_axiom_', '_axiom_init_', '_base', '_cache_an_element', '_cache_key', '_canonize', '_coerce_map_from_', '_coerce_map_via', '_coercions_used', '_convert_map_from_', '_convert_method_map', '_convert_method_name', '_default_decoder_name', '_default_encoder_name', '_defining_names', '_dense_free_module', '_dimension', '_doccls', '_element_constructor_', '_element_constructor_from_element_class', '_facade_for', '_factory_data', '_first_ngens', '_fricas_', '_fricas_init_', '_from_dict', '_gap_', '_gap_init_', '_generator_matrix', '_generic_coerce_map', '_generic_convert_map', '_get_action_', '_giac_', '_giac_init_', '_gp_', '_gp_init_', '_init_category_', '_initial_action_list', '_initial_coerce_list', '_initial_convert_list', '_interface_', '_interface_init_', '_interface_is_cached_', '_internal_coerce_map_from', '_internal_convert_map_from', '_introspect_coerce', '_is_category_initialized', '_is_coercion_cached', '_is_conversion_cached', '_is_valid_homomorphism_', '_kash_', '_kash_init_', '_latex_', '_length', '_macaulay2_', '_macaulay2_init_', '_magma_init_', '_maple_', '_maple_init_', '_mathematica_', '_mathematica_init_', '_maxima_', '_maxima_init_', '_maxima_lib_', '_maxima_lib_init_', '_minimum_distance', '_minimum_weight_codeword', '_module_morphism', '_names', '_octave_', '_octave_init_', '_pari_init_', '_polymake_', '_polymake_init_', '_populate_coercion_lists_', '_punctured_form', '_r_init_', '_reduction', '_refine_category_', '_registered_decoders', '_registered_encoders', '_remove_from_coerce_cache', '_repr_', '_repr_option', '_sage_', '_set_element_constructor', '_singular_', '_singular_init_', '_sum_of_monomials', '_test_additive_associativity', '_test_an_element', '_test_cardinality', '_test_category', '_test_elements', '_test_elements_eq_reflexive', '_test_elements_eq_symmetric', '_test_elements_eq_transitive', '_test_elements_neq', '_test_eq', '_test_new', '_test_not_implemented_methods', '_test_pickling', '_test_some_elements', '_test_zero', '_tester', '_underlying_class', '_unicode_art_', '_unset_category', '_unset_coercions_used', '_unset_embedding', 'add_decoder', 'add_encoder', 'addition_table', 'algebra', 'ambient_space', 'an_element', 'annihilator', 'annihilator_basis', 'assmus_mattson_designs', 'automorphism_group_gens', 'base', 'base_extend', 'base_field', 'base_ring', 'basis', 'binomial_moment', 'canonical_representative', 'cardinality', 'cartesian_product', 'categories', 'category', 'change_ring', 'characteristic', 'characteristic_polynomial', 'chinen_polynomial', 'coerce', 'coerce_embedding', 'coerce_map_from', 'construction', 'convert_map_from', 'covering_radius', 'decode_to_code', 'decode_to_message', 'decoder', 'decoders_available', 'dimension', 'direct_sum', 'divisor', 'dual_code', 'dump', 'dumps', 'echelon_form', 'element_class', 'encode', 'encoder', 'encoders_available', 'endomorphism_ring', 'extended_code', 'facade_for', 'from_vector', 'galois_closure', 'generator_matrix', 'gens', 'gens_dict', 'gens_dict_recursive', 'genus', 'get_action', 'has_coerce_map_from', 'hom', 'information_set', 'inject_variables', 'is_empty', 'is_exact', 'is_finite', 'is_galois_closed', 'is_information_set', 'is_parent_of', 'is_permutation_automorphism', 'is_permutation_equivalent', 'is_projective', 'is_self_dual', 'is_self_orthogonal', 'is_subcode', 'latex_name', 'latex_variable_names', 'length', 'linear_combination', 'list', 'minimum_distance', 'module_composition_factors', 'module_morphism', 'monomial', 'monomial_or_zero_if_none', 'objgen', 'objgens', 'parent', 'parity_check_matrix', 'permutation_automorphism_group', 'permuted_code', 'punctured', 'quotient_module', 'random_element', 'rate', 'redundancy_matrix', 'register_action', 'register_coercion', 'register_conversion', 'register_embedding', 'relative_distance', 'rename', 'reset_name', 'save', 'shortened', 'some_elements', 'spectrum', 'standard_form', 'submodule', 'sum', 'sum_of_monomials', 'sum_of_terms', 'summation', 'summation_from_element_class_add', 'support', 'syndrome', 'systematic_generator_matrix', 'tensor', 'tensor_square', 'term', 'unencode', 'variable_name', 'variable_names', 'weight_distribution', 'weight_enumerator', 'zero', 'zeta_function', 'zeta_polynomial']
comment:27 Changed 19 months ago by
Oh yeah, Python has multiple inheritance, so perhaps AbstractLinearCode
should just be declared as
class AbstractLinearCode(AbstractCode, Module)
and then everything should be fine?
comment:28 in reply to: ↑ 26 ; followup: ↓ 29 Changed 19 months ago by
Replying to jsrn:
I haven't checked out your ticket and compiled, but this is the list of methods I get with
dir(C)
on a freshly createdLinearCode
C
on Sage 8.8.rc3:
Without inheriting from Module
, a fresh LinearCode
on this branch (Sage 8.9.beta4) has more methods, but is missing these: ['base_extend', 'change_ring', 'endomorphism_ring']
.
I added the Module inheritance, will push it with some bigger changes.
comment:29 in reply to: ↑ 28 ; followups: ↓ 31 ↓ 42 Changed 19 months ago by
Replying to ghemes4:
Replying to jsrn:
I haven't checked out your ticket and compiled, but this is the list of methods I get with
dir(C)
on a freshly createdLinearCode
C
on Sage 8.8.rc3:Without inheriting from
Module
, a freshLinearCode
on this branch (Sage 8.9.beta4) has more methods than your list, but is missing these:['base_extend', 'change_ring', 'endomorphism_ring']
.
None of those methods seem to do anything useful, and they don't even make much sense for a (linear) code to begin with. endomorphism_ring
is particularly unfortunate, since we have automorphism_group_gens
which does something very useful, and a user might confuse these.
Perhaps, then, it's better to not inherit from Module
after all?
comment:30 Changed 19 months ago by
 Status changed from needs_work to needs_review
comment:31 in reply to: ↑ 29 ; followup: ↓ 32 Changed 19 months ago by
Replying to jsrn:
None of those methods seem to do anything useful, and they don't even make much sense for a (linear) code to begin with.
endomorphism_ring
is particularly unfortunate, since we haveautomorphism_group_gens
which does something very useful, and a user might confuse these.Perhaps, then, it's better to not inherit from
Module
after all?
IMHO, Module
is too general, here we have free modules, a.k.a. ModulesWithBasis
.
comment:32 in reply to: ↑ 31 ; followup: ↓ 33 Changed 19 months ago by
Replying to dimpase:
Perhaps, then, it's better to not inherit from
Module
after all?IMHO,
Module
is too general, here we have free modules, a.k.a.ModulesWithBasis
.
That's absolutely true. If we inherit from that instead, do these useless methods then go away?
comment:33 in reply to: ↑ 32 Changed 19 months ago by
Replying to jsrn:
Replying to dimpase:
Perhaps, then, it's better to not inherit from
Module
after all?IMHO,
Module
is too general, here we have free modules, a.k.a.ModulesWithBasis
.That's absolutely true. If we inherit from that instead, do these useless methods then go away?
When I add ModulesWithBasis
to the inheritance of AbstractLinearCode
, I get the following error: ValueError: base must be a ring or a subcategory of Rings()
. I am not sure how to fix that?
comment:34 Changed 19 months ago by
I see, this is due to the structure of the category framework: ModulesWithBasis
is a category (i.e. the set of all modules with a basis). We are standing with a single "module with basis", so we should put that into the category. But there is no class ModuleWithBasis
(singular). So the way this is done is to inherit from Module
and then use a magic incantation to tell the category framework that this is not just any module, it is a module with basis. That's exactly what is currently done in AbstractLinearCode
.
Looking at the definition of sage.modules.modules.Module
, I don't see anything useful for LinearCode
s to inherit. On the other hand, it's probably not a good idea to put a parent object into the category of modules (with basis) without that parent object actually being a module. At least, any strong type system would cry ;)
So I suggest just keeping the status quo by using multiple inheritance so AbstractLinearCode
inherits from both AbstractCode
and Module
(in that order).
comment:35 Changed 19 months ago by
comment:36 Changed 19 months ago by
 Dependencies set to #27634
comment:37 followup: ↓ 39 Changed 19 months ago by
I propose adding a method ambient_space
to AbstractCode
which throws a NotImplementedError
. It should be documented that it is recommended (but not required) to override this method. Then we can also move the __call__
method of AbstractLinearCode
to AbstractCode
.
comment:38 Changed 19 months ago by
 Status changed from needs_review to needs_work
comment:39 in reply to: ↑ 37 ; followup: ↓ 40 Changed 19 months ago by
Replying to jsrn:
I propose adding a method
ambient_space
toAbstractCode
which throws aNotImplementedError
. It should be documented that it is recommended (but not required) to override this method. Then we can also move the__call__
method ofAbstractLinearCode
toAbstractCode
.
Is this method required by the encoder/decoder framework?
comment:40 in reply to: ↑ 39 ; followup: ↓ 43 Changed 19 months ago by
Replying to ghemes4:
Replying to jsrn:
I propose adding a method
ambient_space
toAbstractCode
which throws aNotImplementedError
. It should be documented that it is recommended (but not required) to override this method. Then we can also move the__call__
method ofAbstractLinearCode
toAbstractCode
.Is this method required by the encoder/decoder framework?
Well, __call__
is a natural method for any code that is encodable, so it naturally fits to AbstractCode
. Generally in Sage for a parent P
then P(e)
for some value e
does one of two things (which abstractly is maybe the same thing):
 It "coerces"
e
into being something that can be considered to be inP
. So you converte
into the shape objects inP
have. E.g. ifF
is a field thenF(1)
gives you the 1element of that field.
 It uses
e
as an input to create an object inP
. E.g. ifP
is a polynomial ring thenP[1,2,3]
creates the polynomial1 + 2*x + 3*x^2
.
If P
is some linear code C
, then Item 1 is supported in the sense that if e
is a vector in the ambient space of C
, then C(e)
returns e
if e
is in C
, otherwise it throws an error. Not the most useful function perhaps, but it follows this coercioen convention of SageMath.
Item 2, however, can naturally be considered to be encoding  after all, that's the canonical way you would "construct" a codeword. Due to the convention that the default encoder should always use F[x]^k
as the message space, then if e
is a vector of length k
then C(e)
returns the encoding of e
as a codeword.
A funny (disturbing?) detail I never considered before is that if C
is an [n,n]
code, then the current implementation always uses Item 1, i.e. it doesn't encode.
Anyway, this convention absolutely makes sense for any type of code I could think of. So, it should be on AbstractCode
. For that to work, ambient_space()
has to be on AbstractCode
as well. But since we don't really want to force a representation of the ambient space (since it would be some clumsy cartesian product in the general case), then we should just leave it to subclasses to fill out.
In any case, it is a natural function to expect a code to have, i.e. if I was writing in a strongly typed language like Java or C#, then AbstractCode
would be an interface, and I would require ambient_space
to be a method that had to be implemented in subclasses.
comment:41 Changed 19 months ago by
 Commit changed from 9608a237aeabcaf56416bc26475a6b3c0433e6c0 to 318b4441b0e2f7ee1b1275f733e5f43b64b3669e
Branch pushed to git repo; I updated commit sha1. Last 10 new commits:
c8706ee  Merge branch 'develop'

fb35c2f  Fixes responding to reviewer comments

0b95c1d  Manual table for codes_catalog.py

1bca13c  Merge branch 'u/jsrn/27634'

6bf9f1e  Remove unwanted names under codes

24df329  A minor fix in the main document

6c7012b  A pyflakes fix in linear_code.py

c650b8a  Rename channel_constructions.py and goppa.py

5230b19  Merge #27634

318b444  Module inheritance. Ambient_space and __call__ changes.

comment:42 in reply to: ↑ 29 ; followup: ↓ 45 Changed 19 months ago by
Replying to jsrn:
Replying to ghemes4:
Replying to jsrn:
I haven't checked out your ticket and compiled, but this is the list of methods I get with
dir(C)
on a freshly createdLinearCode
C
on Sage 8.8.rc3:Without inheriting from
Module
, a freshLinearCode
on this branch (Sage 8.9.beta4) has more methods than your list, but is missing these:['base_extend', 'change_ring', 'endomorphism_ring']
.None of those methods seem to do anything useful, and they don't even make much sense for a (linear) code to begin with.
endomorphism_ring
is particularly unfortunate,
endomorphism ring provides maps onto subcodes, which does not look as totally useless to me.
changing the ring (taking a bigger ring) produces an additive code.
comment:43 in reply to: ↑ 40 ; followup: ↓ 46 Changed 19 months ago by
Replying to jsrn:
In any case, it is a natural function to expect a code to have, i.e. if I was writing in a strongly typed language like Java or C#, then
AbstractCode
would be an interface, and I would requireambient_space
to be a method that had to be implemented in subclasses.
Thank you for the explanation, makes things much clearer!
I did all the changes, namely added Module
to inheritance of AbstractLinearCode
, merged #27634, added ambient_space
method to AbstractCode
with a recommendation to implement it, and moved __call__
from AbstractLinearCode
to AbstractCode
.
comment:44 Changed 19 months ago by
 Status changed from needs_work to needs_review
comment:45 in reply to: ↑ 42 Changed 19 months ago by
Replying to dimpase:
endomorphism ring provides maps onto subcodes, which does not look as totally useless to me.
Quite true. I have never seen people study it, but probably some people have. And it does have the same type of meaning as automorphism_group_gens
. It's just inconsistent and unfortunate that that method is not called automorphism_ring
and wraps the returned generators in some appropriate algebraic object.
changing the ring (taking a bigger ring) produces an additive code.
OK, I'm not familiar with those. But of course you can take a linear code over some field F_q
and then consider its generator matrix as part of F_{q^m}
and look at the code there. That would even be trivial to implement (but does not belong in this ticket).
comment:46 in reply to: ↑ 43 Changed 19 months ago by
Replying to ghemes4:
I did all the changes, namely added
Module
to inheritance ofAbstractLinearCode
, merged #27634, addedambient_space
method toAbstractCode
with a recommendation to implement it, and moved__call__
fromAbstractLinearCode
toAbstractCode
.
Awesome! I'm happy now :) Dima, your turn ;)
comment:47 followup: ↓ 50 Changed 19 months ago by
 Status changed from needs_review to needs_work
I am getting (on the branch of the ticket)
sage t warnlong 47.5 src/doc/en/thematic_tutorials/structures_in_coding_theory.rst ********************************************************************** File "src/doc/en/thematic_tutorials/structures_in_coding_theory.rst", line 450, in doc.en.thematic_tutorials.structures_in_coding_theory Failed example: from sage.coding.channel_constructions import Channel Exception raised: Traceback (most recent call last): File "/home/dimpase/sage/local/lib/python2.7/sitepackages/sage/doctest/forker.py", line 681, in _run self.compile_and_execute(example, compiler, test.globs) File "/home/dimpase/sage/local/lib/python2.7/sitepackages/sage/doctest/forker.py", line 1105, in compile_and_execute exec(compiled, globs) File "<doctest doc.en.thematic_tutorials.structures_in_coding_theory[0]>", line 1, in <module> from sage.coding.channel_constructions import Channel ImportError: No module named channel_constructions ********************************************************************** File "src/doc/en/thematic_tutorials/structures_in_coding_theory.rst", line 451, in doc.en.thematic_tutorials.structures_in_coding_theory Failed example: class BinaryStaticErrorRateChannel(Channel): def __init__(self, space, number_errors): if space.base_ring() is not GF(2): raise ValueError("Provided space must be a vector space over GF(2)") if number_errors > space.dimension(): raise ValueErrors("number_errors cannot be bigger than input space's dimension") super(BinaryStaticErrorRateChannel, self).__init__(space, space) self._number_errors = number_errors Exception raised: Traceback (most recent call last): File "/home/dimpase/sage/local/lib/python2.7/sitepackages/sage/doctest/forker.py", line 681, in _run self.compile_and_execute(example, compiler, test.globs) File "/home/dimpase/sage/local/lib/python2.7/sitepackages/sage/doctest/forker.py", line 1105, in compile_and_execute exec(compiled, globs) File "<doctest doc.en.thematic_tutorials.structures_in_coding_theory[1]>", line 1, in <module> class BinaryStaticErrorRateChannel(Channel): NameError: name 'Channel' is not defined ********************************************************************** 1 item had failures: 2 of 45 in doc.en.thematic_tutorials.structures_in_coding_theory [28 tests, 2 failures, 0.11 s]
comment:48 Changed 19 months ago by
there is also a typo, please apply the following:
 a/src/sage/coding/abstract_code.py +++ b/src/sage/coding/abstract_code.py @@ 353,7 +353,7 @@ class AbstractCode(Parent): r""" Return an error stating ``ambient_space`` of ``self`` is not implemented.  This method is required by the :method:`__call__`. + This method is required by the :meth:`__call__`. EXAMPLES::
comment:49 Changed 19 months ago by
 Commit changed from 318b4441b0e2f7ee1b1275f733e5f43b64b3669e to 4dbc8789f4ef1e173987df7ba6e13769eacff2ac
Branch pushed to git repo; I updated commit sha1. New commits:
3996761  Merge commit '8b01cc5df9e1508250976b08b4d2212aecb02927' of git://trac.sagemath.org/sage into t/28073/abstract_code

a4582a3  Merge branch 'develop' of git://trac.sagemath.org/sage into t/28073/abstract_code

4dbc878  documentation fix

comment:50 in reply to: ↑ 47 Changed 19 months ago by
Replying to dimpase:
I am getting (on the branch of the ticket)
This was an error coming from #27634, https://trac.sagemath.org/ticket/27634#comment:40. It was fixed on the ticket, I merged the updated branch.
I fixed the small documentation mistake.
I ran the whole test suite make ptestlong
and there were no errors.
comment:51 Changed 19 months ago by
 Status changed from needs_work to needs_review
comment:53 Changed 18 months ago by
 Cc caruso added
comment:54 Changed 18 months ago by
 Cc ghAdurand8 added
comment:55 Changed 18 months ago by
 Reviewers changed from Dima Pasechnik to Dima Pasechnik, ghAdurand8
 Status changed from needs_review to positive_review
comment:56 Changed 18 months ago by
 Status changed from positive_review to needs_work
reviewer names should be real names.
comment:57 Changed 18 months ago by
 Reviewers changed from Dima Pasechnik, ghAdurand8 to Dima Pasechnik, Durand Amaury
 Status changed from needs_work to positive_review
Sorry, I missed this information. It's corrected !
comment:58 Changed 17 months ago by
 Milestone changed from sage8.9 to sage9.0
moving milestone to 9.0 (after release of 8.9)
comment:59 Changed 17 months ago by
 Branch changed from u/ghemes4/coding/abstract_code to 4dbc8789f4ef1e173987df7ba6e13769eacff2ac
 Resolution set to fixed
 Status changed from positive_review to closed
New commits:
AbstractCode class created, cut relevant methods from linear_code.py
Reverted base_field and length to be only in linear_code.py
Merge branch 'develop' of git://trac.sagemath.org/sage into abstract_code
added base_ring and length parameter to AbstractCode
Fixed some dependencies. Category still set up wrong.
Merge branch 'abstract_code' into t/28073/abstract_code