X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2FTODO;h=70e945ed4bbe499bd6dde2a92c0153e30f1dede0;hb=5b1f16399286eba471884a1cfe45247b3a0a7693;hp=427a9539bb69aa4ab25e0687f0336a09377d57e0;hpb=2eb57d9d9487ef2533c177d2771a7c47b2528c4b;p=sage.d.git

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 427a953..70e945e 100644
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -1,8 +1,4 @@
-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.
 
@@ -15,10 +11,16 @@ 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. Actually, this is
-   probably better implemented as a dimension_over_reals() method
-   that returns 1, 2, or 4.
+5. Profile the construction of "large" matrix algebras (like the
+   15-dimensional QuaternionHermitianAlgebra(3)) to find out why
+   they're so slow.
 
-6. The main EJA element constructor is happy to convert between
-   e.g. HadamardEJA(3) and JordanSpinEJA(3).
+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.
+
+7. When field=RDF, subalgebra construction is failing because the
+   inner product isn't associative? Actually, it's the combination
+   of field=RDF and orthonormalize=True.