X-Git-Url: http://gitweb.michael.orlitzky.com/?p=sage.d.git;a=blobdiff_plain;f=mjo%2Feja%2FTODO;h=45a9ac06bf2c86020dee102143393e486fa408c5;hp=db363ac3facd6c3c7475bf9b426664320c19951b;hb=cf5e64b70869df65c7bb38888de54b1083e60d45;hpb=308d65140d9822b9542fafff0708004b1364368e diff --git a/mjo/eja/TODO b/mjo/eja/TODO index db363ac..45a9ac0 100644 --- a/mjo/eja/TODO +++ b/mjo/eja/TODO @@ -1,35 +1,22 @@ -1. Add CartesianProductEJA. +1. Add references and start citing them. -2. Add references and start citing them. +2. Pre-cache charpoly for some more algebras. -3. Implement the octonion simple EJA. +3. Profile the construction of "large" matrix algebras (like the + 15-dimensional QuaternionHermitianAlgebra(3)) to find out why + they're so slow. -4. Override random_instance(), one(), et cetera in DirectSumEJA. +4. What the ever-loving fuck is this shit? -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. + sage: O = Octonions(QQ) + sage: e0 = O.monomial(0) + sage: e0*[[[[]]]] + [[[[]]]]*e0 -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. +5. Every once in a long while, the test - This may require supporting "basis" as a list of basis vectors - (as opposed to superalgebra elements) in the subalgebra constructor. + sage: set_random_seed() + sage: x = random_eja().random_element() + sage: x.is_invertible() == (x.det() != 0) -7. The inner product should be an *argument* to the main EJA - constructor. Afterwards, the basis normalization step should be - optional (and enabled by default) for ALL algebras, since any - algebra can have a nonstandard inner-product and its basis can be - normalized with respect to that inner- product. For example, the - HadamardEJA could be equipped with an inner- product that is twice - the usual one. Then for the basis to be orthonormal, we would need - to divide e.g. (1,0,0) by <(1,0,0),(1,0,0)> = 2 to normalize it. - -8. Use charpoly for inverse itself? - -9. Pre-cache charpoly for some small algebras? + in eja_element.py returns False.