sympy: remove tensor mul now fixed in sympy

Author: mloubout

devito/finite_differences/derivative.py

@@ -6,7 +6,7 @@
 from devito.finite_differences.finite_difference import (generic_derivative,
                                                          first_derivative,
                                                          cross_derivative)
-from devito.finite_differences.differentiable import (Differentiable, EvalDiffDerivative,
+from devito.finite_differences.differentiable import (Differentiable, EvalDerivative,
                                                       diffify)
 from devito.finite_differences.tools import direct, transpose
 from devito.tools import as_mapper, as_tuple, filter_ordered, frozendict
@@ -334,7 +334,7 @@ def _eval_fd(self, expr):
         - 3: Evaluate remaining terms (as `g` may need to be evaluated
         at a different point).
         - 4: Apply substitutions.
-        - 5: Cast to an object of type `EvalDiffDerivative` so that we know
+        - 5: Cast to an object of type `EvalDerivative` so that we know
              the argument stems from a `Derivative. This may be useful for
              later compilation passes.
         """
@@ -362,6 +362,6 @@ def _eval_fd(self, expr):
 
         # Step 5: Cast to EvaluatedDerivative
         assert res.is_Add
-        res = EvalDiffDerivative(*res.args, evaluate=False)
+        res = EvalDerivative(*res.args, evaluate=False)
 
         return res

devito/finite_differences/differentiable.py

@@ -10,7 +10,7 @@
 from devito.finite_differences.tools import make_shift_x0
 from devito.logger import warning
 from devito.tools import filter_ordered, flatten
-from devito.types.lazy import Evaluable, EvalDerivative
+from devito.types.lazy import Evaluable
 from devito.types.utils import DimensionTuple
 
 __all__ = ['Differentiable']
@@ -405,8 +405,8 @@ class Mod(DifferentiableOp, sympy.Mod):
     __new__ = DifferentiableOp.__new__
 
 
-class EvalDiffDerivative(DifferentiableOp, EvalDerivative):
-    __sympy_class__ = EvalDerivative
+class EvalDerivative(DifferentiableOp, sympy.Add):
+    __sympy_class__ = sympy.Add
     __new__ = DifferentiableOp.__new__
 
 
@@ -466,7 +466,7 @@ def _(obj):
     @_cls.register(Mul)
     @_cls.register(Pow)
     @_cls.register(Mod)
-    @_cls.register(EvalDiffDerivative)
+    @_cls.register(EvalDerivative)
     def _(obj):
         return obj.__class__
 

devito/types/lazy.py

@@ -1,5 +1,3 @@
-import sympy
-
 __all__ = ['Evaluable']
 
 
@@ -49,15 +47,3 @@ def evaluate(self):
         args = self._evaluate_args()
         evaluate = not all(i is j for i, j in zip(args, self.args))
         return self.func(*args, evaluate=evaluate)
-
-
-# Custom SymPy types used upon evaluation
-
-
-class EvalDerivative(sympy.Add):
-
-    """
-    A sympy.Add representing an expanded finite-difference Derivative.
-    """
-
-    pass

devito/types/tensor.py

@@ -2,8 +2,6 @@
 from cached_property import cached_property
 
 import numpy as np
-from sympy import Dummy
-from sympy.core.decorators import call_highest_priority
 from sympy.core.sympify import converter as sympify_converter
 
 from devito.finite_differences import Differentiable
@@ -123,33 +121,6 @@ def __subfunc_setup__(cls, *args, **kwargs):
             funcs = funcs.tolist()
         return funcs
 
-    @call_highest_priority('__mul__')
-    def __rmul__(self, other):
-        """
-        Prevents Functions to be interpreted as matrices in 2D becaue of `.shape`
-        TODO: Remove after sympy 1.7
-        """
-        if getattr(other, 'is_DiscreteFunction', False):
-            tmp_func = Dummy(other.name)
-            simplemul = super(TensorFunction, self).__rmul__(tmp_func)
-            return simplemul.subs(tmp_func, other)
-        # honest sympy matrices defer to their class's routine
-        if getattr(other, 'is_Matrix', False):
-            return self._eval_matrix_rmul(other)
-        return super(TensorFunction, self).__rmul__(other)
-
-    @call_highest_priority('__rmul__')
-    def __mul__(self, other):
-        """
-        Prevents Functions to be interpreted as matrices in 2D becaue of `.shape`
-        TODO: Remove after sympy 1.7
-        """
-        if getattr(other, 'is_DiscreteFunction', False):
-            tmp_func = Dummy(other.name)
-            simplemul = super(TensorFunction, self).__mul__(tmp_func)
-            return simplemul.subs(tmp_func, other)
-        return super(TensorFunction, self).__mul__(other)
-
     def __getattr__(self, name):
         """
         Try calling a dynamically created FD shortcut.

tests/test_derivatives.py

@@ -5,7 +5,7 @@
 from devito import (Grid, Function, TimeFunction, Eq, Operator, NODE,
                     ConditionalDimension, left, right, centered, div, grad)
 from devito.finite_differences import Derivative, Differentiable
-from devito.finite_differences.differentiable import EvalDiffDerivative
+from devito.finite_differences.differentiable import EvalDerivative
 from devito.symbolics import indexify, retrieve_indexed
 
 _PRECISION = 9
@@ -195,7 +195,7 @@ def test_derivatives_space(self, derivative, dim, order):
 
         s_expr = u.diff(dim).as_finite_difference(indices).evalf(_PRECISION)
         assert(simplify(expr - s_expr) == 0)  # Symbolic equality
-        assert type(expr) == EvalDiffDerivative
+        assert type(expr) == EvalDerivative
         expr1 = s_expr.func(*expr.args)
         assert(expr1 == s_expr)  # Exact equality
 
@@ -215,7 +215,7 @@ def test_second_derivatives_space(self, derivative, dim, order):
         indices = [(dim + i * dim.spacing) for i in range(-width, width + 1)]
         s_expr = u.diff(dim, dim).as_finite_difference(indices).evalf(_PRECISION)
         assert(simplify(expr - s_expr) == 0)  # Symbolic equality
-        assert type(expr) == EvalDiffDerivative
+        assert type(expr) == EvalDerivative
         expr1 = s_expr.func(*expr.args)
         assert(expr1 == s_expr)  # Exact equality