`call(message)` on a linear code or encoder should return a codeword. #20087

johanrosenkilde · 2016-02-19T15:58:59Z

If E is an Encoder for a LinearCode C, one can use E.encode(message), where message is in the appropriate space. E(message) should default to the same behaviour. So should C(message).

Be aware that the category framework specifies that C(c) = c if c in C. This needs to be handled.

CC: @sagetrac-dlucas @ClementPernet @jlavauzelle @sagetrac-danielaugot

Component: coding theory

Keywords: rd3

Author: David Lucas

Branch/Commit: 8ba64ee

Reviewer: Clément Pernet

Issue created by migration from https://trac.sagemath.org/ticket/20087

The text was updated successfully, but these errors were encountered:

sagetrac-dlucas · 2016-02-22T11:52:11Z

Branch: u/dlucas/shortcut_to_encode

sagetrac-git · 2016-02-22T11:58:39Z

Commit: 49c4488

sagetrac-git · 2016-02-22T11:58:39Z

Branch pushed to git repo; I updated commit sha1. New commits:

`49c4488`	`Also defined this shortcut in GRSEvaluationPolynomialEncoder`

sagetrac-dlucas · 2016-02-22T11:59:26Z

comment:3

E(message) now defaults to E.encode(message).
I added a few lines to the documentation of encode in encoder.py and in GRSEvaluationPolynomialEncoder to highlight this shortcut.

Setting this as needs_review.

New commits:

`02c1f6d`	`Shortcut for method encode`
`49c4488`	`Also defined this shortcut in GRSEvaluationPolynomialEncoder`

sagetrac-dlucas · 2016-02-22T11:59:26Z

Author: David Lucas

sagetrac-git · 2016-02-25T15:52:35Z

Branch pushed to git repo; I updated commit sha1. New commits:

`de71938`	`Same shortcut for C(m)`

sagetrac-git · 2016-02-25T15:52:35Z

Changed commit from 49c4488 to de71938

sagetrac-dlucas · 2016-02-25T15:54:43Z

comment:6

I added the same mechanism with codes: let C be a code, and m an element from the message space of the encoder 'encoder'.

C(m, encoder_name='encoder') is now a shortcut to C.encode(m, encoder_name='encoder')

sagetrac-dlucas · 2016-03-18T13:42:56Z

comment:7

There's a doctest failing which indicates the test suite is broken for codes.
That's because in the test suite, there's an idempotency test for element construction.

It picks c = C.an_element() and then tries C(c)... Which of course fails in our case as __call__ has been redefined as encode - and the input of encode cannot be an element of C.

sagetrac-dlucas · 2016-03-18T14:53:58Z

comment:8

Because of the above, which is related to the way linear codes are set in the category framework, it seems impossible to do the proposed improvement.

Setting this to invalid/won't fix.

johanrosenkilde · 2016-03-31T12:51:36Z

comment:9

This issue is not a show-stopper: instead of __call__ simply aliasing self.encode, it is a proper method which checks its input. If the input is a codeword, it returns that unchanged. If the input has the correct length of a message, return the encoded codeword, via self.encode. Otherwise, throw a ValueError.

Re-opening.

sagetrac-git · 2016-03-31T14:25:46Z

Changed commit from de71938 to 872f5d7

sagetrac-git · 2016-03-31T14:25:46Z

Branch pushed to git repo; I updated commit sha1. New commits:

`4cd4b26`	`Merge branch 'develop' into shortcut_to_encode`
`e8d7b58`	`Merge branch 'develop' into shortcut_to_encode`
`872f5d7`	Updated `__call__` method with a proper behaviour

sagetrac-dlucas · 2016-03-31T14:29:38Z

comment:11

Done.
Except for the ValueError. If the input is not a codeword, it passes it to encode which does the check. As encode knows the message space of the encoder to use, it returns a nice error message which specifies the expected input (e.g. "The value to encode must be in Vector space of dimension 4 over Finite Field of size 2").

Maybe leave this review for Daniel as he wanted to do it? I just Cc'd him on this ticket.

sagetrac-panda314 · 2016-04-01T11:40:51Z

comment:12

Hi, Maybe the check of whether the vector passed is a codeword or not can be done before passing it to the encode function. That way if a user means to pass a codeword rather than the message, and passed th wrong vector, he/she will be notified.

johanrosenkilde · 2016-04-01T12:02:24Z

comment:13

David, didn't you accidentally put the Encoder-related code on the GRS encoder? It should be on the abstract class Encoder. Also, the check if m in self should be if m in self.code() on the Encoder. And your doc-test there doesn't test that method.

Replying to @sagetrac-panda314:

Hi, Maybe the check of whether the vector passed is a codeword or not can be done before passing it to the encode function. That way if a user means to pass a codeword rather than the message, and passed th wrong vector, he/she will be notified.

As far as I can see, the check in LinearCode does check for code membership before passing it to the encoder.

sagetrac-git · 2016-04-01T14:07:18Z

Changed commit from 6b32cf0 to ce8d798

sagetrac-dlucas · 2016-04-01T14:08:06Z

comment:23

I vote for not defining Encoder.__call__ as an alias, then, but instead rely on dynamic dispatch to avoid the trap

Yes, it's a good idea. Done in the last commit.

sagetrac-panda314 · 2016-04-01T15:45:18Z

comment:24

are the changes compiling? The copy of this branch is not compiling on my local pc (new to sage, am i missing something?). Here's the error:
InternalError: Internal compiler error: 'cysignals/signals.pxi' not found

Detailed message is,

Traceback (most recent call last):
File "setup.py", line 590, in
    run_cythonize()
File "setup.py", line 582, in run_cythonize
    'profile': profile,
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 758, in cythonize
    aliases=aliases)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 664, in create_extension_list
    kwds = deps.distutils_info(file, aliases, base).values
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 564, in distutils_info
    return (self.transitive_merge(filename, self.distutils_info0, DistutilsInfo.merge)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 574, in transitive_merge
    node, extract, merge, seen, {}, self.cimported_files)![0]
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 579, in transitive_merge_helper
    deps = extract(node)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 555, in distutils_info0
    externs = self.cimports_and_externs(filename)![1]
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Utils.py", line 43, in wrapper
    res = cache[args] = f(self, *args)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 465, in cimports_and_externs
    for include in self.included_files(filename):
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Utils.py", line 43, in wrapper
    res = cache[args] = f(self, *args)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Build/Dependencies.py", line 448, in included_files
    include_path = self.context.find_include_file(include, None)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Compiler/Main.py", line 274, in find_include_file
    error(pos, "'%s' not found" % filename)
File "/home/panda/sage/local/lib/python2.7/site-packages/Cython-0.23.3-py2.7-linux-x86_64.egg/Cython/Compiler/Errors.py", line 177, in error
    raise InternalError(message)
InternalError: Internal compiler error: 'cysignals/signals.pxi' not found

Error building the Sage library

make: *** [sage] Error 1

sagetrac-dlucas · 2016-04-01T16:19:45Z

comment:25

It's compiling on my side. According to the error report you sent, a file is missing on your side.
I guess you'll have to download Sage again and recompile it...

sagetrac-danielaugot · 2016-08-24T10:08:15Z

Changed branch from u/dlucas/shortcut_to_encode to u/danielaugot/shortcut_to_encode

sagetrac-danielaugot · 2016-08-24T10:10:25Z

Changed commit from ce8d798 to 2fa1f17

sagetrac-danielaugot · 2016-08-24T10:10:25Z

comment:27

I used the terminology "ambient space" in the doc string, to avoid being specific in details. Daniel

New commits:

`2fa1f17`	`Better doc string for __call__`

sagetrac-git · 2016-08-24T18:04:45Z

Changed commit from 2fa1f17 to f25413e

sagetrac-git · 2016-08-24T18:04:45Z

Branch pushed to git repo; I updated commit sha1. New commits:

`f25413e`	`Merge branch 'u/danielaugot/shortcut_to_encode' of git://trac.sagemath.org/sage into 20087/shortcut_to_encode`

sagetrac-git · 2016-08-24T18:56:40Z

Changed commit from f25413e to 3ec380c

sagetrac-git · 2016-08-24T18:56:40Z

Branch pushed to git repo; I updated commit sha1. New commits:

`3ec380c`	`fixed the docstring to match the ErrorValue`

sagetrac-git · 2016-08-24T19:03:25Z

Branch pushed to git repo; I updated commit sha1. New commits:

`1fe5d5b`	`easier to understand control structure using if-then-else`

sagetrac-git · 2016-08-24T19:03:25Z

Changed commit from 3ec380c to 1fe5d5b

johanrosenkilde · 2016-09-12T09:02:45Z

Changed branch from u/danielaugot/shortcut_to_encode to u/jsrn/shortcut_to_encode

johanrosenkilde · 2016-09-12T09:09:30Z

comment:32

I mistakenly pushed another branch on top of this one. I've reverted it now -- sorry for the noise.

ClementPernet · 2017-02-07T09:18:29Z

Changed keywords from none to rd3

ClementPernet · 2017-02-07T09:18:29Z

comment:33

Doc string of the __call__ method of encoder (encoder.py:187) should test whether E(p) works not E.encode(p).

ClementPernet · 2017-02-07T09:18:29Z

Reviewer: Clément Pernet

ClementPernet · 2017-02-07T09:21:04Z

Changed branch from u/jsrn/shortcut_to_encode to u/cpernet/shortcut_to_encode

sagetrac-git · 2017-02-07T09:34:32Z

Changed commit from 1fe5d5b to 8ba64ee

sagetrac-git · 2017-02-07T09:34:32Z

Branch pushed to git repo; I updated commit sha1. New commits:

`8ba64ee`	`add missing doctest for C(word)`

ClementPernet · 2017-02-07T09:36:16Z

comment:36

It's all good, after the two minor docstring edits that I've pushed to the ticket. Positive review.

vbraun · 2017-02-08T22:48:53Z

Changed branch from u/cpernet/shortcut_to_encode to 8ba64ee

johanrosenkilde added this to the sage-7.1 milestone Feb 19, 2016

johanrosenkilde added c: coding theory labels Feb 19, 2016

sagetrac-dlucas mannequin added s: needs review labels Feb 22, 2016

sagetrac-dlucas mannequin removed this from the sage-7.1 milestone Mar 18, 2016

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johanrosenkilde added s: needs work and removed s: needs review labels Mar 31, 2016

johanrosenkilde changed the title ~~E(message) for a linear code encoder E should encode message~~ __call__(message) on a linear code or encoder should return a codeword. Mar 31, 2016

johanrosenkilde added this to the sage-7.2 milestone Mar 31, 2016

sagetrac-dlucas mannequin added s: needs review and removed s: needs work labels Mar 31, 2016

ClementPernet added s: positive review and removed s: needs review labels Feb 7, 2017

ClementPernet modified the milestones: sage-7.2, sage-7.6 Feb 7, 2017

vbraun removed the s: positive review label Feb 8, 2017

vbraun closed this as completed in 9d659d9 Feb 8, 2017

sagetrac-dlucas mannequin mentioned this issue Jan 21, 2017

Meta-ticket: enhancement of the coding theory part of Sage #18846

Closed

__call__(message) on a linear code or encoder should return a codeword. #20087

__call__(message) on a linear code or encoder should return a codeword. #20087

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vbraun commented Feb 8, 2017

`call(message)` on a linear code or encoder should return a codeword. #20087

`call(message)` on a linear code or encoder should return a codeword. #20087