eja: don't pass in a full multiplication table unless necessary.

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

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index f0901ca91b793debc4877a8ee5a670d240fa51fc..2752dc47cd026eb9c000be7301507567c2161dfa 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -32,6 +32,11 @@
 
 8. 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]
+
 9. Compute the scalar in the general natural_inner_product() for
    matrices, so no overrides are necessary.
 
@@ -40,3 +45,10 @@
 
 11. Figure out if CombinatorialFreeModule's use of IndexedGenerators
     can be used to replace the matrix_basis().
+
+12. Move the "field" argument to a keyword after basis, jp, and ip.
+
+13. Instead of storing the multiplication and inner-product tables in
+    RationalBasisEuclideanJordanAlgebra, why not just create the
+    algebra over QQ in the constructor and save that? They're globally
+    unique, so we won't wind up with multiple copies.