X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2FTODO;h=e925c162786ab4da9bb7155ec8086cda0da05464;hb=857eeec29a9b89b0e4f711476771c935757fa8dc;hp=db02b276e9a8a427afd3ad2a3e0b9fb77020fb50;hpb=778835152f5d5408017c47b0c1e74db19ab70a69;p=sage.d.git diff --git a/mjo/eja/TODO b/mjo/eja/TODO index db02b27..e925c16 100644 --- a/mjo/eja/TODO +++ b/mjo/eja/TODO @@ -1,37 +1,25 @@ -1. Finish DirectSumEJA: add to_matrix(), random_instance(), - one()... methods. Make it subclass RationalBasisEuclideanJordanAlgebra. - This is not a general direct sum / cartesian product implementation, - it's used only with the other rationalbasis algebras (to make non- - simple EJAs out of the simple ones). +1. Add cartesian products to random_eja(). 2. Add references and start citing them. 3. Implement the octonion simple EJA. -4. 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 using 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. - -5. Pre-cache charpoly for some small algebras? +4. Pre-cache charpoly for some small algebras? RealSymmetricEJA(4): sage: F = J.base_ring() sage: a0 = (1/4)*X[4]**2*X[6]**2 - (1/2)*X[2]*X[5]*X[6]**2 - (1/2)*X[3]*X[4]*X[6]*X[7] + (F(2).sqrt()/2)*X[1]*X[5]*X[6]*X[7] + (1/4)*X[3]**2*X[7]**2 - (1/2)*X[0]*X[5]*X[7]**2 + (F(2).sqrt()/2)*X[2]*X[3]*X[6]*X[8] - (1/2)*X[1]*X[4]*X[6*X[8] - (1/2)*X[1]*X[3]*X[7]*X[8] + (F(2).sqrt()/2)*X[0]*X[4]*X[7]*X[8] + (1/4)*X[1]**2*X[8]**2 - (1/2)*X[0]*X[2]*X[8]**2 - (1/2)*X[2]*X[3]**2*X[9] + (F(2).sqrt()/2)*X[1]*X[3]*X[4]*X[9] - (1/2)*X[0]*X[4]**2*X[9] - (1/2)*X[1]**2*X[5]*X[9] + X[0]*X[2]*X[5]*X[9] -6. Compute the scalar in the general natural_inner_product() for - matrices, so no overrides are necessary. - -7. The main EJA element constructor is happy to convert between - e.g. HadamardEJA(3) and JordanSpinEJA(3). +5. Profile the construction of "large" matrix algebras (like the + 15-dimensional QuaternionHermitianAlgebra(3)) to find out why + they're so slow. -8. Figure out if CombinatorialFreeModule's use of IndexedGenerators - can be used to replace the matrix_basis(). +6. We should compute whether or not the algebra is associative if it + is unknown. I guess the "associative" argument should be ternary + (True, False, None)? We should also figure out the correct + True/False values for the example classes, and of course add an + _is_associative() method. -9. Move the "field" argument to a keyword after basis, jp, and ip. +7. Set check_axioms=False for element-subalgebras outside of once or + twice in the test suite.