eja: fix cartesian products of cartesian product EJAs.

[sage.d.git] / mjo / eja / TODO

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index cf870aedc40b1901ca81be9442ebf3d5b5f855cd..93aa9fb42e6ec6cdba6963db8dacfddd116ba762 100644 (file)
--- 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.
 
@@ -17,3 +16,7 @@ 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
 
 5. The main EJA element constructor is happy to convert between
    e.g. HadamardEJA(3) and JordanSpinEJA(3).
+
+6. Profile the construction of "large" matrix algebras (like the
+   15-dimensional QuaternionHermitianAlgebra(3)) to find out why
+   they're so slow.