eja: speed up det() for Cartesian product elements.

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

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 1def3d2e9fd8cf381ae743344ce670a13f226438..9cee421b4f5cacee4e623a6b4d1099c191eeaf72 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -2,19 +2,10 @@
 
 2. Profile (and fix?) any remaining slow operations.
 
-3. Every once in a long while, the test
+3. When we take a Cartesian product involving a trivial algebra, we
+   could easily cache the identity and charpoly coefficients using
+   the nontrivial factor. On the other hand, it's nice that we can
+   test out some alternate code paths...
 
-       sage: set_random_seed()
-       sage: x = random_eja().random_element()
-       sage: x.is_invertible() == (x.det() != 0)
-
-   in eja_element.py returns False. Example:
-
-       sage: J1 = ComplexHermitianEJA(2)
-       sage: J2 = TrivialEJA()
-       sage: J = cartesian_product([J1,J2])
-       sage: x = J.from_vector(vector(QQ, [-1, -1/2, -1/2, -1/2]))
-       sage: x.is_invertible()
-       True
-       sage: x.det()
-       0
+4. Add dimension bounds on any tests over AA that compute element
+   subalgebras.