X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2Feja_subalgebra.py;h=95534db842408f08480d012d6464fadf0c3e7fd4;hb=b40f0964ea523f9063d62ec1772a5d698bf9c26a;hp=a774b985ff54a2ceeb01468b5887849a22ef2d65;hpb=9c35b8d70e384cd98b8ec7eb7a84cf84db1d1137;p=sage.d.git

diff --git a/mjo/eja/eja_subalgebra.py b/mjo/eja/eja_subalgebra.py
index a774b98..95534db 100644
--- a/mjo/eja/eja_subalgebra.py
+++ b/mjo/eja/eja_subalgebra.py
@@ -24,39 +24,6 @@ class FiniteDimensionalEuclideanJordanElementSubalgebraElement(FiniteDimensional
         True
 
     """
-    def __init__(self, A, elt):
-        """
-        SETUP::
-
-            sage: from mjo.eja.eja_algebra import RealSymmetricEJA
-            sage: from mjo.eja.eja_subalgebra import FiniteDimensionalEuclideanJordanElementSubalgebra
-
-        EXAMPLES::
-
-            sage: J = RealSymmetricEJA(3)
-            sage: x = sum( i*J.gens()[i] for i in range(6) )
-            sage: K = FiniteDimensionalEuclideanJordanElementSubalgebra(x)
-            sage: [ K.element_class(K,x^k) for k in range(J.rank()) ]
-            [f0, f1, f2]
-
-        ::
-
-        """
-        if elt in A.superalgebra():
-            # Try to convert a parent algebra element into a
-            # subalgebra element...
-            try:
-                coords = A.vector_space().coordinate_vector(elt.to_vector())
-                elt = A.from_vector(coords).monomial_coefficients()
-            except AttributeError:
-                # Catches a missing method in elt.to_vector()
-                pass
-
-        s = super(FiniteDimensionalEuclideanJordanElementSubalgebraElement,
-                  self)
-
-        s.__init__(A, elt)
-
 
     def superalgebra_element(self):
         """
@@ -75,9 +42,9 @@ class FiniteDimensionalEuclideanJordanElementSubalgebraElement(FiniteDimensional
             sage: x
             e0 + e1 + e2 + e3 + e4 + e5
             sage: A = x.subalgebra_generated_by()
-            sage: A.element_class(A,x)
+            sage: A(x)
             f1
-            sage: A.element_class(A,x).superalgebra_element()
+            sage: A(x).superalgebra_element()
             e0 + e1 + e2 + e3 + e4 + e5
 
         TESTS:
@@ -88,10 +55,10 @@ class FiniteDimensionalEuclideanJordanElementSubalgebraElement(FiniteDimensional
             sage: J = random_eja()
             sage: x = J.random_element()
             sage: A = x.subalgebra_generated_by()
-            sage: A.element_class(A,x).superalgebra_element() == x
+            sage: A(x).superalgebra_element() == x
             True
             sage: y = A.random_element()
-            sage: A.element_class(A,y.superalgebra_element()) == y
+            sage: A(y.superalgebra_element()) == y
             True
 
         """
@@ -134,21 +101,18 @@ class FiniteDimensionalEuclideanJordanElementSubalgebra(FiniteDimensionalEuclide
         field = superalgebra.base_ring()
         mult_table = []
         for b_right in superalgebra_basis:
-                b_right_rows = []
-                # The first row of the right-multiplication matrix by
+                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 row of the right multiplication matrix by b1
+                # second column of the left-multiplication matrix by b1
                 # is what we get when we apply that matrix to b2...
-                #
-                # IMPORTANT: this assumes that all vectors are COLUMN
-                # vectors, unlike our superclass (which uses row vectors).
                 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_row = W.coordinates((b_left*b_right).to_vector())
-                    b_right_rows.append(this_row)
-                b_right_matrix = matrix(field, b_right_rows)
+                    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:
@@ -184,6 +148,32 @@ class FiniteDimensionalEuclideanJordanElementSubalgebra(FiniteDimensionalEuclide
                               natural_basis=natural_basis)
 
 
+    def _element_constructor_(self, elt):
+        """
+        Construct an element of this subalgebra from the given one.
+        The only valid arguments are elements of the parent algebra
+        that happen to live in this subalgebra.
+
+        SETUP::
+
+            sage: from mjo.eja.eja_algebra import RealSymmetricEJA
+            sage: from mjo.eja.eja_subalgebra import FiniteDimensionalEuclideanJordanElementSubalgebra
+
+        EXAMPLES::
+
+            sage: J = RealSymmetricEJA(3)
+            sage: x = sum( i*J.gens()[i] for i in range(6) )
+            sage: K = FiniteDimensionalEuclideanJordanElementSubalgebra(x)
+            sage: [ K(x^k) for k in range(J.rank()) ]
+            [f0, f1, f2]
+
+        ::
+
+        """
+        if elt in self.superalgebra():
+            coords = self.vector_space().coordinate_vector(elt.to_vector())
+            return self.from_vector(coords)
+
 
     def superalgebra(self):
         """
@@ -207,15 +197,15 @@ class FiniteDimensionalEuclideanJordanElementSubalgebra(FiniteDimensionalEuclide
             sage: K.vector_space()
             Vector space of degree 6 and dimension 3 over Rational Field
             User basis matrix:
-            [ 1  0  0  1  0  1]
+            [ 1  0  1  0  0  1]
             [ 0  1  2  3  4  5]
-            [ 5 11 14 26 34 45]
+            [10 14 21 19 31 50]
             sage: (x^0).to_vector()
-            (1, 0, 0, 1, 0, 1)
+            (1, 0, 1, 0, 0, 1)
             sage: (x^1).to_vector()
             (0, 1, 2, 3, 4, 5)
             sage: (x^2).to_vector()
-            (5, 11, 14, 26, 34, 45)
+            (10, 14, 21, 19, 31, 50)
 
         """
         return self._vector_space