#20103: Some clean up in simplicial complexes
----------------------------------+---------------------------------
Reporter: jhpalmieri | Owner:
Type: enhancement | Status: new
Priority: minor | Milestone: sage-7.1
Component: algebraic topology | Keywords:
Merged in: | Authors: John Palmieri
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies:
Stopgaps: |
----------------------------------+---------------------------------
This in some sense a followup to #6102 and in some sense a precursor a
future ticket for simplicial sets. This mainly involves some
reorganization, not much new.
- Add a `reduced` keyword to the `homology` method, to make it easy to
compute unreduced homology. (Computing reduced homology has always been
the default, but it was a little inconvenient to compute the unreduced
homology before.)
- Add an `is_acyclic` method for cell complexes.
- Instead of having a single `algebraic_topological_model` method for all
cell complexes, broken into cases depending on the complex, instead each
class which inherits from `GenericCellComplex` should implement its own
method.
- Similarly, cell complexes should have an `alexander_whitney` method.
This helps to clean up the cup product code; that code should be easy to
maintain if we add more types of cell complexes.
- Change `__cmp__` to `__eq__` etc., for all types of cells and complexes.
My understanding is that `__cmp__` is no longer used in Python 3, so we
should eliminate it.
- For simplicial complexes, define a `face` method: then `K.face(sigma,
i)` will return the ith face of `sigma` in `K`. This is not really useful
on its own, but it gets used in the `Sq` method in
`homology_vector_space_with_basis`. The point is, we could define cell
complexes (like the current Delta complexes, and like simplicial sets) in
which you can only compute the face of a cell by knowing about the complex
in which it lives, and we might want to extend the `Sq` method to work
with such complexes.
--
Ticket URL: <http://trac.sagemath.org/ticket/20103>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
