Opened 4 years ago

Closed 4 years ago

Last modified 4 years ago

#26851 closed enhancement (fixed)

py3: avoid .vertices() and .edges() in union of graphs

Reported by: David Coudert Owned by:
Priority: major Milestone: sage-8.6
Component: graph theory Keywords: py3, graph
Cc: Travis Scrimshaw, Frédéric Chapoton Merged in:
Authors: David Coudert Reviewers: Frédéric Chapoton
Report Upstream: N/A Work issues:
Branch: 3e1ee4b (Commits, GitHub, GitLab) Commit: 3e1ee4b4232b37aecbac06b6c96340c72ada9c16
Dependencies: Stopgaps:

Status badges

Description (last modified by David Coudert)

This change is not without consequences. Indeed, when adding vertices to the graph G resulting from the union of self and other, the order in which vertices are added to G fixes the ordering list(G).

For instance, this change breaks the graph generator EllinghamHorton54Graph that uses several times disjoint_union which itself calls union and that uses the ordering of list(G) to relabel vertices. Also, we change the generator to something simpler and more robust.

Change History (4)

comment:1 Changed 4 years ago by David Coudert

Branch: public/26851_union
Cc: Travis Scrimshaw Frédéric Chapoton added
Commit: 3e1ee4b4232b37aecbac06b6c96340c72ada9c16
Description: modified (diff)
Status: newneeds_review

New commits:

942309btrac #26851: avoid .vertices and .edges in union
3e1ee4btrac #26851: fix EllinghamHorton54Graph

comment:2 Changed 4 years ago by Frédéric Chapoton

Reviewers: Frédéric Chapoton
Status: needs_reviewpositive_review

ok, let it be

comment:3 Changed 4 years ago by Volker Braun

Branch: public/26851_union3e1ee4b4232b37aecbac06b6c96340c72ada9c16
Resolution: fixed
Status: positive_reviewclosed

comment:4 Changed 4 years ago by Erik Bray

Milestone: sage-8.5sage-8.6

This tickets were closed as fixed after the Sage 8.5 release.

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