Opened 5 years ago
Closed 5 years ago
#19360 closed enhancement (fixed)
Poset documentation polishing: comparing & intervals
Reported by:  jmantysalo  Owned by:  

Priority:  minor  Milestone:  sage6.10 
Component:  documentation  Keywords:  
Cc:  kdilks  Merged in:  
Authors:  Jori Mäntysalo  Reviewers:  Kevin Dilks 
Report Upstream:  N/A  Work issues:  
Branch:  f406e5e (Commits)  Commit:  f406e5e86e7f37ed9693e6ad6860de43020dbbc9 
Dependencies:  Stopgaps: 
Change History (12)
comment:1 Changed 5 years ago by
 Cc kdilks added
comment:2 Changed 5 years ago by
I thought I responded to this, but maybe this was the response I had typed out just after my free 30 minute wifi session at O'Hare expired...
I don't think relations are often (or ever) called intervals. So deprecate that, but maybe add a docstring comment to relations()
indicating that the number of relations is the number of intervals, and is thus the dimension of the incidence algebra.
Not especially a fan of comparable_pairs()
, just because technically speaking pairs are unordered, and we care about the order of the pair. I also don't think chains(size=2)
would be a good option, either.
The way that I think of posets (and the way the poset constructor thinks of them) is that you have data of a ground set and relations, and how all of that data interacts makes a poset structure. Things like chains and intervals are properties of the entire poset structure, whereas relations are an individual piece of the defining data.
comment:3 Changed 5 years ago by
 Branch set to u/jmantysalo/poset_documentation_polishing__comparing___intervals
comment:4 Changed 5 years ago by
 Commit set to 9dcc412a4416aa7b8fad962b1d0f974f7460922a
Branch pushed to git repo; I updated commit sha1. New commits:
9dcc412  A typo in the index.

comment:5 Changed 5 years ago by
What should I do to interval
? Now it is de facto alias to closed_interval
(or to other way), but technically a function.
comment:6 Changed 5 years ago by
 Commit changed from 9dcc412a4416aa7b8fad962b1d0f974f7460922a to aea0eff7c7f5bce8ebf9d218a0df6c2c0575bd0a
Branch pushed to git repo; I updated commit sha1. New commits:
aea0eff  More polishing to docstrings.

comment:7 Changed 5 years ago by
 Status changed from new to needs_review
I guess this can be reviewed as it is.
Different question is that should open_interval(x, y)
and open_interval(y, x)
return just same elements.
comment:8 Changed 5 years ago by
 Commit changed from aea0eff7c7f5bce8ebf9d218a0df6c2c0575bd0a to 3cc556da45d5540a3cfb7536777102548ba5edca
Branch pushed to git repo; I updated commit sha1. New commits:
3cc556d  Change one .intervals() to .relations().

comment:9 Changed 5 years ago by
 Commit changed from 3cc556da45d5540a3cfb7536777102548ba5edca to f406e5e86e7f37ed9693e6ad6860de43020dbbc9
Branch pushed to git repo; I updated commit sha1. New commits:
f406e5e  Resolved a conflict with new beta.

comment:10 Changed 5 years ago by
 Reviewers set to Kevin Dilks
 Status changed from needs_review to positive_review
I don't think open_interval(x,y)
and open_interval(y,x)
should always return the same thing.
Looks good.
comment:11 Changed 5 years ago by
Thank you! Now this is starting to look quite good.
comment:12 Changed 5 years ago by
 Branch changed from u/jmantysalo/poset_documentation_polishing__comparing___intervals to f406e5e86e7f37ed9693e6ad6860de43020dbbc9
 Resolution set to fixed
 Status changed from positive_review to closed
Kevin, what you think about "Relations are also often called intervals."? I would say that every comparable element pair defines an interval, not that it is an interval. Actually the name of
intervals()
/relations()
could becomparable_pairs()
, or even notyetimplementedchains(size=2)
. But maybe that would go too far.But should we deprecate
intervals
, as it does not return intervals but a pairs of elements?