X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2FTODO;h=93aa9fb42e6ec6cdba6963db8dacfddd116ba762;hb=21fa036e86711c6c28b6d89af2b1bfe4ceb24b29;hp=ccd0b5ae507312c68d7a5e61d5094cfab617b7c5;hpb=162d7eaa821faa07e7886d8e21308b716aabd747;p=sage.d.git

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index ccd0b5a..93aa9fb 100644
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -1,8 +1,7 @@
-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. Finish CartesianProductEJA: add to_matrix(), random_instance(),...
+   methods. I guess we should create a separate class hierarchy for
+   Cartesian products of RationalBasisEJA? That way we get fast
+   charpoly and random_instance() defined...
 
 2. Add references and start citing them.
 
@@ -15,13 +14,9 @@ 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]
 
-5. Compute the scalar in the general natural_inner_product() for
-   matrices, so no overrides are necessary.
-
-6. The main EJA element constructor is happy to convert between
+5. The main EJA element constructor is happy to convert between
    e.g. HadamardEJA(3) and JordanSpinEJA(3).
 
-7. Figure out if CombinatorialFreeModule's use of IndexedGenerators
-   can be used to replace the matrix_basis().
-
-8. Move the "field" argument to a keyword after basis, jp, and ip.
+6. Profile the construction of "large" matrix algebras (like the
+   15-dimensional QuaternionHermitianAlgebra(3)) to find out why
+   they're so slow.