Speedup creation of spin crystals

[tscrim]

Currently, when we construct a spin crystal, we build the full digraph to implement a comparison operation. This ticket, in effect, makes constructing the digraph a lazy attribute which gets called when doing the comparison operation.

CC: @sagetrac-sage-combinat @anneschilling

Component: combinatorics

Keywords: spin crystals

Author: Travis Scrimshaw

Branch/Commit: d237ec2

Reviewer: Anne Schilling

Issue created by migration from https://trac.sagemath.org/ticket/18922

[tscrim]

Branch: public/crystals/speedup_spin_construction-18922

[tscrim]

comment:1

I also did some cleanup:

• I removed the caching of the elements since the e/f operations aren't cached (which I think is where the real speed gains are) and it was a hack IMO.

• I removed the list command because that (and the respective caching) is done by FiniteEnumeratedSets (and will result in a speedup for iteration after calling .list() once).

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New commits:

7bbaef2

Speed up creation of spin crystals.

[tscrim]

Commit: 7bbaef2

[anneschilling]

comment:2

Instead of deleting the tests for the methods that you removed, it would be better if they would be moved (perhaps as tests for the class). Also, could you provide timings and an example where this was a problem before?

Thanks,

Anne

[tscrim]

comment:3

The .list() test is already in the function which creates the B_n spin crystal object, so I just added back the element construction example to the _element_constructor_ and added a test to check for consistency. Here are my timings.

With branch:

sage: %time C = crystals.SpinsPlus(['D',6])
CPU times: user 472 µs, sys: 58 µs, total: 530 µs
Wall time: 542 µs
sage: %time C = crystals.SpinsPlus(['D',7])
CPU times: user 453 µs, sys: 56 µs, total: 509 µs
Wall time: 523 µs
sage: %time C = crystals.SpinsMinus(['D',8])
CPU times: user 0 ns, sys: 0 ns, total: 0 ns
Wall time: 956 µs
sage: %time C = crystals.Spins(['B',10])
CPU times: user 488 µs, sys: 56 µs, total: 544 µs
Wall time: 490 µs

Before:

sage: %time C = crystals.SpinsPlus(['D',6])
CPU times: user 465 ms, sys: 69.7 ms, total: 535 ms
Wall time: 549 ms
sage: %time C = crystals.SpinsPlus(['D',7])
CPU times: user 52 ms, sys: 12.7 ms, total: 64.7 ms
Wall time: 58.6 ms
sage: %time C = crystals.SpinsMinus(['D',8])
CPU times: user 223 ms, sys: 20.6 ms, total: 244 ms
Wall time: 228 ms
sage: %time C = crystals.Spins(['B',10])
I got tired after waiting for 10 minutes and killed it and then ran this:
sage: %time C = crystals.Spins(['B',8])
CPU times: user 2.59 s, sys: 24 ms, total: 2.61 s
Wall time: 2.58 s

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

12277f1

Added back doctest.

[sagetrac-git]

Changed commit from 7bbaef2 to 12277f1

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

d237ec2

Merge branch 'develop' into public/crystals/speedup_spin_construction-18922

[sagetrac-git]

Changed commit from 12277f1 to d237ec2

[anneschilling]

comment:6

Ok, looks good!

[anneschilling]

Reviewer: Anne Schilling

[vbraun]

Changed branch from public/crystals/speedup_spin_construction-18922 to d237ec2