LatticePoset: add atoms, coatoms, doubly irreducibles etc.

[jm58660]

Add atoms(), coatoms(), and doubly_irreducibles() to finite lattices.

Component: combinatorics

Keywords: latticeposet

Author: Jori Mäntysalo

Branch: aa58591

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/19190

[jm58660]

Branch: u/jmantysalo/latticeposet__add_atoms__coatoms__doubly_irreducibles_etc_

[jm58660]

comment:4

This patch will add three functions. Also this will make LatticePoset() to return the empty lattice; compare to Poset().

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New commits:

429b494

Add atoms() etc.

[jm58660]

Changed keywords from poset to latticeposet

[jm58660]

Commit: 429b494

[tscrim]

comment:5

On my to-review list.

[tscrim]

Changed commit from 429b494 to aa58591

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

Changed branch from u/jmantysalo/latticeposet__add_atoms__coatoms__doubly_irreducibles_etc_ to public/posets/add_methods-19190

[tscrim]

comment:6

I did some (additional) touchups to the finite lattice category and minor tweaks. While I still prefer ``self`` over this lattice, the lattice is not correct as there is not a unique lattice. If you agree with my changes, then go ahead and set a positive review.

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New commits:

376adfb	Some cleanup in the category docstrings.
aa58591	Some touchups of lattices.py.

[jm58660]

comment:7

In html documentation "See also: FinitePosets, LatticePosets, LatticePoset" the "LatticePoset" is a broken link. Where is it supposed to point?

About "the": I don't understand. For example docstring for cardinality() is "Return the number of elements in the poset." I have think that "the" means about same as "this" in that sentence.

[jm58660]

comment:8

Btw, I run doctests and they were successfull. So patchbots again give false errors.

[jm58660]

comment:9

Anyways, Sage with this patch is better than without, hence I mark this as positive_review.

Broken links are more general problem. Nathann give one suggestion at #20095, but that should be talked separately.

[vbraun]

Changed branch from public/posets/add_methods-19190 to aa58591

[tscrim]

comment:11

"the" implies uniqueness, but there is not a unique poset. "this" within the context gives uniqueness. In fact, I would change all of those "the" to "this".

[tscrim]

Changed commit from aa58591 to none

[jm58660]

comment:12

Replying to @tscrim:

"the" implies uniqueness, but there is not a unique poset. "this" within the context gives uniqueness. In fact, I would change all of those "the" to "this".

Trying to understand... There is no direct translation for a/an/the in Finnish.

I have learnt that if I say "Travis, open the window", it means that I have one specific window in my mind and I suppose that you also know what window I mean. "Open a window" means that there are several to choose one, and I don't care which one you open.

In "Return the number of elements in the poset." I suppose that it is clear what poset we are referring to.

[tscrim]

comment:13

Replying to @jm58660:

Replying to @tscrim:

"the" implies uniqueness, but there is not a unique poset. "this" within the context gives uniqueness. In fact, I would change all of those "the" to "this".

Trying to understand... There is no direct translation for a/an/the in Finnish.

I have absolutely zero understanding of Finnish (I don't think I've ever really encountered any before).

I have learnt that if I say "Travis, open the window", it means that I have one specific window in my mind and I suppose that you also know what window I mean. "Open a window" means that there are several to choose one, and I don't care which one you open.

Yes, provided there is only one window we are discussing.

In "Return the number of elements in the poset." I suppose that it is clear what poset we are referring to.

In a way, yes, but it is more precise to say "this poset" as there might be one more poset around (especially when there is another input of a poset).