eja: drop cached superalgebra basis from subalgebras.

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

diff --git a/mjo/eja/eja_subalgebra.py b/mjo/eja/eja_subalgebra.py
index 045c16e7ed691532e016c89192a43903bc0cc7ce..2ceba43b9f6ad40e110aa2f2365ac45ffb69e288 100644 (file)
--- a/mjo/eja/eja_subalgebra.py
+++ b/mjo/eja/eja_subalgebra.py
@@ -56,6 +56,14 @@ class FiniteDimensionalEuclideanJordanSubalgebraElement(FiniteDimensionalEuclide
             f1
             sage: A(x).superalgebra_element()
             e0 + e1 + e2 + e3 + e4 + e5
+            sage: y = sum(A.gens())
+            sage: y
+            f0 + f1
+            sage: B = y.subalgebra_generated_by()
+            sage: B(y)
+            g1
+            sage: B(y).superalgebra_element()
+            f0 + f1
 
         TESTS:
 
@@ -72,8 +80,12 @@ class FiniteDimensionalEuclideanJordanSubalgebraElement(FiniteDimensionalEuclide
             True
 
         """
-        return self.parent().superalgebra().linear_combination(
-          zip(self.parent()._superalgebra_basis, self.to_vector()) )
+        W = self.parent().vector_space()
+        V = self.parent().superalgebra().vector_space()
+        A = W.basis_matrix().transpose()
+        W_coords = A*self.to_vector()
+        V_coords = V.coordinate_vector(W_coords)
+        return self.parent().superalgebra().from_vector(V_coords)
 
 
 
@@ -130,7 +142,7 @@ class FiniteDimensionalEuclideanJordanSubalgebra(FiniteDimensionalEuclideanJorda
         1
 
     """
-    def __init__(self, superalgebra, basis, category=None):
+    def __init__(self, superalgebra, basis, category=None, check_axioms=True):
         self._superalgebra = superalgebra
         V = self._superalgebra.vector_space()
         field = self._superalgebra.base_ring()
@@ -153,7 +165,11 @@ class FiniteDimensionalEuclideanJordanSubalgebra(FiniteDimensionalEuclideanJorda
         superalgebra_basis = [ self._superalgebra.from_vector(b)
                                for b in basis_vectors ]
 
+        # If our superalgebra is a subalgebra of something else, then
+        # these vectors won't have the right coordinates for
+        # V.span_of_basis() unless we use V.from_vector() on them.
         W = V.span_of_basis( V.from_vector(v) for v in basis_vectors )
+
         n = len(superalgebra_basis)
         mult_table = [[W.zero() for i in range(n)] for j in range(n)]
         for i in range(n):
@@ -171,15 +187,15 @@ class FiniteDimensionalEuclideanJordanSubalgebra(FiniteDimensionalEuclideanJorda
 
 
         self._vector_space = W
-        self._superalgebra_basis = superalgebra_basis
-
 
         fdeja = super(FiniteDimensionalEuclideanJordanSubalgebra, self)
         fdeja.__init__(field,
                        mult_table,
                        prefix=prefix,
                        category=category,
-                       natural_basis=natural_basis)
+                       natural_basis=natural_basis,
+                       check_field=False,
+                       check_axioms=check_axioms)