eja: move away from using matrices as our "multiplication table."

[sage.d.git] / mjo / eja / eja_subalgebra.py

diff --git a/mjo/eja/eja_subalgebra.py b/mjo/eja/eja_subalgebra.py
index 95534db842408f08480d012d6464fadf0c3e7fd4..22fa870fb551624f9b9c47f181cd8aa023944cb6 100644 (file)
--- a/mjo/eja/eja_subalgebra.py
+++ b/mjo/eja/eja_subalgebra.py
@@ -99,25 +99,12 @@ class FiniteDimensionalEuclideanJordanElementSubalgebra(FiniteDimensionalEuclide
         # matrix for the successive basis elements b0, b1,... of
         # that subspace.
         field = superalgebra.base_ring()
-        mult_table = []
-        for b_right in superalgebra_basis:
-                b_right_cols = []
-                # The first column of the left-multiplication matrix by
-                # b1 is what we get if we apply that matrix to b1. The
-                # second column of the left-multiplication matrix by b1
-                # is what we get when we apply that matrix to b2...
-                for b_left in superalgebra_basis:
-                    # Multiply in the original EJA, but then get the
-                    # coordinates from the subalgebra in terms of its
-                    # basis.
-                    this_col = W.coordinates((b_left*b_right).to_vector())
-                    b_right_cols.append(this_col)
-                b_right_matrix = matrix.column(field, b_right_cols)
-                mult_table.append(b_right_matrix)
-
-        for m in mult_table:
-            m.set_immutable()
-        mult_table = tuple(mult_table)
+        n = len(superalgebra_basis)
+        mult_table = [[W.zero() for i in range(n)] for j in range(n)]
+        for i in range(n):
+            for j in range(n):
+                product = superalgebra_basis[i]*superalgebra_basis[j]
+                mult_table[i][j] = W.coordinate_vector(product.to_vector())
 
         # TODO: We'll have to redo this and make it unique again...
         prefix = 'f'