Opened 7 years ago

Closed 5 years ago

#17330 closed defect (fixed)

Take in the module OEIS the keyword 'dead' of sequences into account.

Reported by: pluschny Owned by:
Priority: major Milestone: sage-7.2
Component: misc Keywords: OEIS
Cc: moritz Merged in:
Authors: Moritz Firsching Reviewers: Vincent Delecroix
Report Upstream: N/A Work issues:
Branch: d416ecc (Commits, GitHub, GitLab) Commit: d416ecc5b115a8b1f00b0290fe0ecf8325b72bc2
Dependencies: Stopgaps:

Status badges

Description

OEIS functions should simply ignore sequences with the keyword 'dead'. At least they should not attempt to return terms of these sequences.

For example the sequence A000017 https://oeis.org/A000017 is 'dead', what means it has errors in the data and was replaced by another version. It is policy of the OEIS to keep such sequences so they can be found in the case they are referenced in the literature.

As it is now oeis(17).first_terms(12) throws the TypeError?: You found a sign inconsistency, please contact OEIS

Change History (12)

comment:1 Changed 5 years ago by moritz

  • Branch set to u/moritz/ticket/17330
  • Cc moritz added
  • Commit set to 8ea4b1a1c8c29d8221e9a5d486ccc1f2c433271d

Here is how this could be fixed (see git branch).

When doctesting this, I noticed the another bug:

**********************************************************************
File "src/sage/databases/oeis.py", line 845, in sage.databases.oeis.OEISSequence.keywords
Failed example:
    f.keywords()                          # optional -- internet
Expected:
    ('core', 'nonn', 'nice', 'easy', 'hear')
Got:
    ('core', 'nonn', 'nice', 'easy', 'hear', 'changed')
**********************************************************************

This is due to the fact that the keyword 'changed' is temporarily added, so this would go away after a while. I propose to change that example to a sequence that is not altered as often as the Fibonacci numbers (see commit)


New commits:

8ea4b1afirst try to fix 17330

comment:2 Changed 5 years ago by moritz

  • Status changed from new to needs_review

comment:3 Changed 5 years ago by git

  • Commit changed from 8ea4b1a1c8c29d8221e9a5d486ccc1f2c433271d to 10c15fcd72e4dfe044e8bdc6112e00c160eb6faa

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

10c15fcsecond try to fix 17330

comment:4 Changed 5 years ago by moritz

  • Milestone changed from sage-6.4 to sage-7.2

comment:5 Changed 5 years ago by vdelecroix

You should put your full name in the "Authors" field.

comment:6 Changed 5 years ago by moritz

  • Authors set to Moritz Firsching

done

comment:7 Changed 5 years ago by vdelecroix

  • Status changed from needs_review to needs_info

The patch provided does not do what is in the description. Namely the dead sequences are not ignored!

I would add an explicit error message like

sage: oeis(17)
Traceback (most recent call last):
...
ValueError: this sequence is dead "A000017: Erroneous version of A032522."

Possibly, you could add an option to get it even if it is dead

sage: oeis(17, force=True)
A000017: Erroneous version of A032522.

comment:8 Changed 5 years ago by git

  • Commit changed from 10c15fcd72e4dfe044e8bdc6112e00c160eb6faa to d416ecc5b115a8b1f00b0290fe0ecf8325b72bc2

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

d416eccadding a warning

comment:9 Changed 5 years ago by vdelecroix

  • Reviewers set to Vincent Delecroix
  • Status changed from needs_info to positive_review

Better!

comment:10 Changed 5 years ago by moritz

  • Reviewers Vincent Delecroix deleted

Perhaps throwing an error is too much? I just pushed a version where you have a warning..

comment:11 Changed 5 years ago by vdelecroix

  • Reviewers set to Vincent Delecroix

yeap. this is fine. (I rewrote my name as a reviewer)

comment:12 Changed 5 years ago by vbraun

  • Branch changed from u/moritz/ticket/17330 to d416ecc5b115a8b1f00b0290fe0ecf8325b72bc2
  • Resolution set to fixed
  • Status changed from positive_review to closed
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