eja: fix the natural representation in trivial subalgebras.

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

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 06f6f531ac46305da59ec2b4290ba808602cea50..42b2474d6971d81c8a1fcda67b079892a3e8af25 100644 (file)
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -9,6 +9,7 @@ from sage.algebras.quatalg.quaternion_algebra import QuaternionAlgebra
 from sage.categories.magmatic_algebras import MagmaticAlgebras
 from sage.combinat.free_module import CombinatorialFreeModule
 from sage.matrix.constructor import matrix
+from sage.matrix.matrix_space import MatrixSpace
 from sage.misc.cachefunc import cached_method
 from sage.misc.prandom import choice
 from sage.misc.table import table
@@ -514,11 +515,23 @@ class FiniteDimensionalEuclideanJordanAlgebra(CombinatorialFreeModule):
 
         """
         if self._natural_basis is None:
-            return tuple( b.to_vector().column() for b in self.basis() )
+            M = self.natural_basis_space()
+            return tuple( M(b.to_vector()) for b in self.basis() )
         else:
             return self._natural_basis
 
 
+    def natural_basis_space(self):
+        """
+        Return the matrix space in which this algebra's natural basis
+        elements live.
+        """
+        if self._natural_basis is None or len(self._natural_basis) == 0:
+            return MatrixSpace(self.base_ring(), self.dimension(), 1)
+        else:
+            return self._natural_basis[0].matrix_space()
+
+
     @cached_method
     def one(self):
         """