eja: fix sub-subalgebra element construction.

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

diff --git a/mjo/eja/eja_subalgebra.py b/mjo/eja/eja_subalgebra.py
index ac77f22a691e7cc04138e34cae46f148909de0f8..4355e9f20e40d1a396f42a686d474c77e18f1b47 100644 (file)
--- a/mjo/eja/eja_subalgebra.py
+++ b/mjo/eja/eja_subalgebra.py
@@ -215,8 +215,12 @@ class FiniteDimensionalEuclideanJordanSubalgebra(FiniteDimensionalEuclideanJorda
         if elt not in self.superalgebra():
             raise ValueError("not an element of this subalgebra")
 
-        coords = self.vector_space().coordinate_vector(elt.to_vector())
-        return self.from_vector(coords)
+        # The extra hackery is because foo.to_vector() might not
+        # live in foo.parent().vector_space()!
+        coords = sum( a*b for (a,b)
+                          in zip(elt.to_vector(),
+                                 self.superalgebra().vector_space().basis()) )
+        return self.from_vector(self.vector_space().coordinate_vector(coords))