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

[sage.d.git] / mjo / symbolic.py

diff --git a/mjo/symbolic.py b/mjo/symbolic.py
index ec3fc99e1e451b95b33eed22790b3dc089f617d1..3760596c66e3f8f53cded6dbb9b3f9f636324387 100644 (file)
--- a/mjo/symbolic.py
+++ b/mjo/symbolic.py
@@ -46,43 +46,45 @@ def safe_simplify(expr):
     return expr
 
 
-def matrix_subs_expr(m, *equations):
+def matrix_simplify_full(A):
     """
-    Symbolic matrices have a `subs()` method, but no `subs_expr()`.
-    This makes it diffucult to substitute in a list of solutions obtained
-    with `solve()`.
+    Simplify each entry of a symbolic matrix using the
+    Expression.simplify_full() method.
 
     INPUT:
 
-      - ``m`` -- A symbolic matrix.
-
-      - ``equations`` - One or more symbolic equations, presumably for
-        the entries of `m`.
+      - ``A`` - The matrix whose entries we should simplify.
 
     OUTPUT:
 
-    The result of substituting each equation into `m`, one after another.
+    A copy of ``A`` with all of its entries simplified.
 
-    EXAMPLES::
+    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]
+    Symbolic matrices (examples stolen from Expression.simplify_full())
+    will have their entries simplified::
 
-    """
-    from sage.symbolic.expression import is_SymbolicEquation
+        sage: a,n,k = SR.var('a,n,k')
+        sage: f1 = sin(x)^2 + cos(x)^2
+        sage: f2 = sin(x/(x^2 + x))
+        sage: f3 = binomial(n,k)*factorial(k)*factorial(n-k)
+        sage: f4 = x*sin(2)/(x^a)
+        sage: A = matrix(SR, [[f1,f2],[f3,f4]])
+        sage: matrix_simplify_full(A)
+        [                1    sin(1/(x + 1))]
+        [     factorial(n) x^(-a + 1)*sin(2)]
 
-    if not m.base_ring() == SR:
-        raise TypeError, 'the matrix "m" must be symbolic'
+    But an exception will be raised if ``A`` is not symbolic::
 
-    if isinstance(equations[0], dict):
-        eq_dict = equations[0]
-        equations = [ x == eq_dict[x] for x in eq_dict.keys() ]
+        sage: A = matrix(QQ, [[1,2],[3,4]])
+        sage: matrix_simplify_full(A)
+        Traceback (most recent call last):
+        ...
+        ValueError: The base ring of `A` must be the Symbolic Ring.
 
-    if not all([is_SymbolicEquation(eq) for eq in equations]):
-            raise TypeError, "each expression must be an equation"
+    """
+    if not A.base_ring() == SR:
+        raise ValueError('The base ring of `A` must be the Symbolic Ring.')
 
-    d = dict([(eq.lhs(), eq.rhs()) for eq in equations])
-    return m.subs(d)
+    M = A.matrix_space()
+    return M(map(lambda x: x.simplify_full(), A))