Opened 8 years ago
Closed 17 months ago
#14068 closed defect (fixed)
nauty_geng is naughty
Reported by:  azi  Owned by:  jason, ncohen, rlm 

Priority:  major  Milestone:  sage9.0 
Component:  graph theory  Keywords:  
Cc:  dimpase  Merged in:  
Authors:  David Coudert, Dima Pasechnik  Reviewers:  Dima Pasechnik 
Report Upstream:  N/A  Work issues:  
Branch:  93edfb0 (Commits, GitHub, GitLab)  Commit:  93edfb05921b4fba999b9eda0c7f128d99be1f36 
Dependencies:  Stopgaps: 
Description (last modified by )
I think nauty_geng should not ignore geng's return value and return an exception if the returned value is not 0. Consider the following:
def find_counterexample(n): for G in graphs.nauty_geng("c" + str(n)): if is_counterexample(G): print 'Yeees, there is a counterexample' return print 'No counterexamples! Conjecture holds'
the code appears to be just fine but it has a bug! Namely it tries to run the program geng with the parameter "cn" instead of "c n". Hence geng returns an error and instead of getting an error in Sage, it simply does not generate any graphs.
The branch implements the catching of geng's error. We also clean up the code of graph_generators a bit.
Change History (14)
comment:1 Changed 8 years ago by
 Cc changed from rbeezer,ncohen, dcoudert to rbeezer, ncohen, dcoudert
 Milestone changed from sage5.11 to sage5.12
comment:2 Changed 7 years ago by
 Milestone changed from sage6.1 to sage6.2
comment:3 Changed 7 years ago by
 Milestone changed from sage6.2 to sage6.3
comment:4 Changed 7 years ago by
 Milestone changed from sage6.3 to sage6.4
comment:5 Changed 18 months ago by
 Branch set to public/graphs/14068_nauty
 Commit set to 759fab2f8961aa5ab7e6d5e57ac96f9625f70080
 Milestone changed from sage6.4 to sage8.9
 Status changed from new to needs_review
comment:6 followup: ↓ 8 Changed 18 months ago by
I don't understand the reported pyflakes error with sage.graphs.strongly_regular_db
. Other modules are imported the same way without causing pyflakes errors.
comment:7 Changed 18 months ago by
 Cc dimpase added; rbeezer ncohen dcoudert removed
comment:8 in reply to: ↑ 6 Changed 17 months ago by
Replying to dcoudert:
I don't understand the reported pyflakes error with
sage.graphs.strongly_regular_db
. Other modules are imported the same way without causing pyflakes errors.
perhaps pyflakes is confused by staticmethod()
thing.
The only place where a method from strongly_regular_db
is used is
strongly_regular_graph = staticmethod(sage.graphs.strongly_regular_db.strongly_regular_graph)
by the way, I don't understand why it's not written as
from . import strongly_regular_db ... strongly_regular_graph = staticmethod(strongly_regular_db.strongly_regular_graph)
Is it cause this code predates from .
syntax?
comment:9 Changed 17 months ago by
 Commit changed from 759fab2f8961aa5ab7e6d5e57ac96f9625f70080 to 93edfb05921b4fba999b9eda0c7f128d99be1f36
Branch pushed to git repo; I updated commit sha1. New commits:
93edfb0  refactoring using 'from .' syntax

comment:10 Changed 17 months ago by
OK, otherwise looks good. let's see if this commit makes pyflakes happy
comment:11 Changed 17 months ago by
pyflakes is now happy !
comment:12 Changed 17 months ago by
 Description modified (diff)
 Reviewers set to Dima Pasechnik
 Status changed from needs_review to positive_review
comment:13 Changed 17 months ago by
 Milestone changed from sage8.9 to sage9.0
moving milestone to 9.0 (after release of 8.9)
comment:14 Changed 17 months ago by
 Branch changed from public/graphs/14068_nauty to 93edfb05921b4fba999b9eda0c7f128d99be1f36
 Resolution set to fixed
 Status changed from positive_review to closed
A possible fix is to raise an error only when parameter debug is False and that something goes wrong.
When debug is True, the behavior remains the same as before and so we continue to display the message output by geng in stderr.
New commits:
trac #14068: check input when debug is False