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@tscrim tscrim commented Mar 30, 2024

We implement the algorithms in de Graaf to compute the solvable and nilradicals of a finite dimensional Lie algebra. To do so, we also make further improvements to how subalgebras and ideals of Lie algebras are constructed and handled.

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  • The title is concise and informative.
  • The description explains in detail what this PR is about.
  • I have linked a relevant issue or discussion.
  • I have created tests covering the changes.
  • I have updated the documentation accordingly.

⌛ Dependencies

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mkoeppe commented Apr 3, 2024

Test failures in clifford_algebra

@tscrim tscrim force-pushed the lie_algebras/solvable_nil_radical branch from d92aa8c to 005a6c5 Compare April 9, 2024 10:33
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Documentation preview for this PR (built with commit abf746e; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

@tscrim tscrim force-pushed the lie_algebras/solvable_nil_radical branch from 005a6c5 to 8be290b Compare May 7, 2024 03:51
"""
if sparse:
return self.value.sparse_vector()
return self.value

cpdef to_vector(self, bint sparse=False, order=None):
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why can it just ignore the order parameter?
(Of course I see that the original code did the same.)

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Because the implementation is based on a fixed order and it is added for (signature) compatibility with the generic implementation.

(b, c, d)

sage: SL = L.subalgebra([a,b,c,d]); SL
Subalgebra generated by (a, b, c, d) of Lie algebra on 5 generators (a, b, c, d, e) over Rational Field
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Suggested change
Subalgebra generated by (a, b, c, d) of Lie algebra on 5 generators (a, b, c, d, e) over Rational Field
Subalgebra generated by (a, b, c, d) of
Lie algebra on 5 generators (a, b, c, d, e) over Rational Field

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throughout I recommend to break long output at column 88 so that it fits in the formatted HTML doc

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I did this everywhere I felt it was at most a net-zero improvement in readability.

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Otherwise LGTM

@tscrim tscrim force-pushed the lie_algebras/solvable_nil_radical branch from 8be290b to abf746e Compare May 28, 2024 08:18
@tscrim tscrim removed the v: large label May 28, 2024
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LGTM. Let's ship it.

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tscrim commented Jun 4, 2024

Thank you!

vbraun pushed a commit to vbraun/sage that referenced this pull request Jun 5, 2024
sagemathgh-37697: Implement the solvable and nil radicals of a finite dimensional Lie algebra
    
<!-- ^ Please provide a concise and informative title. -->
<!-- ^ Don't put issue numbers in the title, do this in the PR
description below. -->
<!-- ^ For example, instead of "Fixes sagemath#12345" use "Introduce new method
to calculate 1 + 2". -->
<!-- v Describe your changes below in detail. -->
<!-- v Why is this change required? What problem does it solve? -->
<!-- v If this PR resolves an open issue, please link to it here. For
example, "Fixes sagemath#12345". -->

We implement the algorithms in de Graaf to compute the solvable and
nilradicals of a finite dimensional Lie algebra. To do so, we also make
further improvements to how subalgebras and ideals of Lie algebras are
constructed and handled.

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [x] I have created tests covering the changes.
- [x] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on. For example,
-->
<!-- - sagemath#12345: short description why this is a dependency -->
<!-- - sagemath#34567: ... -->

- sagemath#37693 Uses this in the computation
- sagemath#37682 Needs the improvements here
    
URL: sagemath#37697
Reported by: Travis Scrimshaw
Reviewer(s): Matthias Köppe, Travis Scrimshaw
@vbraun vbraun merged commit 8daa182 into sagemath:develop Jun 9, 2024
@tscrim tscrim deleted the lie_algebras/solvable_nil_radical branch June 9, 2024 23:18
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3 participants