Remove matrix_subs_expr() now that subs() absorbed its features.

diff --git a/mjo/symbolic.py b/mjo/symbolic.py
index 0afd5a5651ce9dedc3bccab518a6b5f4ec0ee492..3760596c66e3f8f53cded6dbb9b3f9f636324387 100644 (file)
--- a/mjo/symbolic.py
+++ b/mjo/symbolic.py
@@ -46,48 +46,6 @@ def safe_simplify(expr):
     return expr
 
 
-def matrix_subs_expr(m, *equations):
-    """
-    Symbolic matrices have a `subs()` method, but no `subs_expr()`.
-    This makes it diffucult to substitute in a list of solutions obtained
-    with `solve()`.
-
-    INPUT:
-
-      - ``m`` -- A symbolic matrix.
-
-      - ``equations`` - One or more symbolic equations, presumably for
-        the entries of `m`.
-
-    OUTPUT:
-
-    The result of substituting each equation into `m`, one after another.
-
-    EXAMPLES::
-
-    sage: w,x,y,z = SR.var('w,x,y,z')
-    sage: A = matrix(SR, [[w,x],[y,z]])
-    sage: matrix_subs_expr(A, w == 1, x == 2, y == 3, z == 4)
-    [1 2]
-    [3 4]
-
-    """
-    from sage.symbolic.expression import is_SymbolicEquation
-
-    if not m.base_ring() == SR:
-        raise TypeError, 'the matrix "m" must be symbolic'
-
-    if isinstance(equations[0], dict):
-        eq_dict = equations[0]
-        equations = [ x == eq_dict[x] for x in eq_dict.keys() ]
-
-    if not all([is_SymbolicEquation(eq) for eq in equations]):
-            raise TypeError, "each expression must be an equation"
-
-    d = dict([(eq.lhs(), eq.rhs()) for eq in equations])
-    return m.subs(d)
-
-
 def matrix_simplify_full(A):
     """
     Simplify each entry of a symbolic matrix using the