Opened 10 years ago
Closed 10 years ago
#13222 closed defect (fixed)
Fix is_graded for Posets to use appropriate definition
Reported by: | Anne Schilling | Owned by: | Sage Combinat CC user |
---|---|---|---|
Priority: | major | Milestone: | sage-5.2 |
Component: | combinatorics | Keywords: | sd40, posets |
Cc: | Sage Combinat CC user | Merged in: | sage-5.2.beta1 |
Authors: | Franco Saliola | Reviewers: | Anne Schilling |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
Fix is_graded to use the following definition a poset is graded if
all maximal chains have the same lengths
. See Stanley, EC1.
As per this definition, the following poset is not graded:
sage: P = Poset([[1,2,3,4], [[1,2],[2,4],[3,4]]]) sage: P.is_graded() True
Beware that not everybody agree on this choice of definition for ranked / graded. See http://en.wikipedia.org/wiki/Graded_poset.
Attachments (1)
Change History (13)
comment:1 Changed 10 years ago by
Description: | modified (diff) |
---|---|
Reviewers: | Anne Schilling and SD40 → Anne Schilling, SD40 |
Summary: | Fixing is_graded for Posets → Fix is_graded for Posets to use appropriate definition |
comment:2 Changed 10 years ago by
Description: | modified (diff) |
---|
comment:3 Changed 10 years ago by
Description: | modified (diff) |
---|
comment:4 Changed 10 years ago by
Description: | modified (diff) |
---|
comment:5 Changed 10 years ago by
Status: | new → needs_review |
---|
comment:6 Changed 10 years ago by
Description: | modified (diff) |
---|---|
Keywords: | posets added |
Changed 10 years ago by
Attachment: | trac_13222_is_graded_for_posets.patch added |
---|
comment:7 Changed 10 years ago by
comment:8 Changed 10 years ago by
Status: | needs_review → positive_review |
---|
comment:9 Changed 10 years ago by
Positive review if all tests pass on Patchbot (only tested all Tests in /combinat/posets).
comment:10 follow-up: 11 Changed 10 years ago by
Milestone: | sage-5.3 → sage-5.2 |
---|---|
Reviewers: | Anne Schilling, SD40 → Anne Schilling |
Not sure whether "SD40" as reviewer makes much sense, mind if I remove it?
comment:11 Changed 10 years ago by
Replying to jdemeyer:
Not sure whether "SD40" as reviewer makes much sense, mind if I remove it?
Sure. We wrote and sort of reviewed the patch during a tutorial at Sage Days 40, so I wanted to give everyone credit for it since many people gave input during the writing and reviewing.
Anne
comment:12 Changed 10 years ago by
Merged in: | → sage-5.2.beta1 |
---|---|
Resolution: | → fixed |
Status: | positive_review → closed |
This patch was written and reviewed during the tutorial session lead by Franco Saliola and Anne Schilling during Sage Days 40 with all participants.
Positive review.