graph canonical labels and doctest failures in databases/sql_db.py #26994
Description
Starting from somewhere around 8.5.beta the canonical labels given by Sage and bliss are different on some instances
sage: G1 = Graph("Cr")
sage: G2 = Graph("C]")
sage: G1 == G2
False
sage: G1.is_isomorphic(G2) and G2.is_isomorphic(G1)
True
sage: G1.canonical_label(algorithm='bliss') == G1
True
sage: G1.canonical_label(algorithm='sage') == G2
True
That is Cr is canonical for bliss while C] is canonical for Sage... More examples:
- 4 vertices:
C`vsCK,CRvsCLandCrvsC] - 5 vertices:
DGCvsD@O,DAKvsD@S,DC[vsD@s,DIKvsDBW,DD[vsDBk,DDWvsDBg,D`{vsDK{,DqKvsDLo,DMkvsDbk,DR{vsDL{,DR[vsDJk,Dr{vsD]{
As a consequence, when bliss is installed, we have the two following doctest failures in databases/sql_db.py.
sage -t --long src/sage/databases/sql_db.py
**********************************************************************
File "src/sage/databases/sql_db.py", line 956, in
sage.databases.sql_db.SQLDatabase.__init__
Failed example:
D.show('simon')
Expected:
graph6 vertices edges
------------------------------------------------------------
? 0 0
@ 1 0
A? 2 0
A_ 2 1
B? 3 0
BG 3 1
BW 3 2
Bw 3 3
C? 4 0
C@ 4 1
CB 4 2
CF 4 3
CJ 4 3
CK 4 2
CL 4 3
CN 4 4
C] 4 4
C^ 4 5
C~ 4 6
Got:
graph6 vertices edges
------------------------------------------------------------
? 0 0
@ 1 0
A? 2 0
A_ 2 1
B? 3 0
BG 3 1
BW 3 2
Bw 3 3
C? 4 0
C@ 4 1
CB 4 2
CF 4 3
CJ 4 3
C` 4 2
CR 4 3
CN 4 4
Cr 4 4
C^ 4 5
C~ 4 6
**********************************************************************
File "src/sage/databases/sql_db.py", line 1004, in
sage.databases.sql_db.SQLDatabase.__init__
Failed example:
E.show('simon')
Expected:
graph6 vertices edges
------------------------------------------------------------
? 0 0
@ 1 0
A? 2 0
A_ 2 1
B? 3 0
BG 3 1
BW 3 2
Bw 3 3
C? 4 0
C@ 4 1
CB 4 2
CF 4 3
CJ 4 3
CK 4 2
CL 4 3
CN 4 4
C] 4 4
C^ 4 5
C~ 4 6
Got:
graph6 vertices edges
------------------------------------------------------------
? 0 0
@ 1 0
A? 2 0
A_ 2 1
B? 3 0
BG 3 1
BW 3 2
Bw 3 3
C? 4 0
C@ 4 1
CB 4 2
CF 4 3
CJ 4 3
C` 4 2
CR 4 3
CN 4 4
Cr 4 4
C^ 4 5
C~ 4 6
**********************************************************************
1 item had failures:
2 of 26 in sage.databases.sql_db.SQLDatabase.__init__
[288 tests, 2 failures, 1.59 s]
Component: documentation
Author: David Coudert
Branch/Commit: a1a96fa
Reviewer: Volker Braun
Issue created by migration from https://trac.sagemath.org/ticket/26994