X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2FTODO;h=82c49d53d883d40712b66897c115ed1e58fa430f;hb=42571e06964e4a9891614793fb0fc8d7e1dd069d;hp=f09191e3890ea4589ccc5fae3da3e27c2a23b6b8;hpb=db5226c4f5478db40d844b99077a5b164ef6d714;p=sage.d.git diff --git a/mjo/eja/TODO b/mjo/eja/TODO index f09191e..82c49d5 100644 --- a/mjo/eja/TODO +++ b/mjo/eja/TODO @@ -1,24 +1,15 @@ -1. Add CartesianProductEJA. +1. Add references and start citing them. -2. Add references and start citing them. +2. Profile (and fix?) any remaining slow operations. -3. Implement the octonion simple EJA. +3. When we take a Cartesian product involving a trivial algebra, we + could easily cache the identity and charpoly coefficients using + the nontrivial factor. On the other hand, it's nice that we can + test out some alternate code paths... -4. Override random_instance(), one(), et cetera in DirectSumEJA. +4. Conjecture: if x = (x1,x2), then det(x) = det(x1)det(x2). This + should be used to fix the fact that det(x) is monstrously slow in + Cartesian product algebras, and thus randomly in the doctests. -5. Switch to QQ in *all* algebras for _charpoly_coefficients(). - This only works when we know that the basis can be rationalized... - which is the case at least for the concrete EJAs we provide, - but not in general. - -6. Pass already_echelonized (default: False) and echelon_basis - (default: None) into the subalgebra constructor. The value of - already_echelonized can be passed to V.span_of_basis() to save - some time, and usinf e.g. FreeModule_submodule_with_basis_field - we may somehow be able to pass the echelon basis straight in to - save time. - - This may require supporting "basis" as a list of basis vectors - (as opposed to superalgebra elements) in the subalgebra constructor. - -7. Use charpoly for inverse stuff if it's cached. +5. Add dimension bounds on any tests over AA that compute element + subalgebras.