api: enforce valid coordinates for inject/interp

Author: mloubout

devito/operations/interpolators.py

@@ -34,6 +34,34 @@ def wrapper(interp, *args, **kwargs):
     return wrapper
 
 
+def check_coords(func):
+    @wraps(func)
+    def wrapper(interp, *args, **kwargs):
+        inputs = args + as_tuple(kwargs.get('expr', ()))
+
+        # SubFunction of the SparseFunction use to create the interpolator
+        sfunc = interp.sfunction
+
+        # SubFunctions found in the arguments of the interpolation/injection operation
+        a_sfuncs = {f for f in retrieve_functions(inputs)
+                    if f.is_SparseFunction} - {sfunc}
+        if not a_sfuncs:
+            # Only uses the the interpolator's SparseFunction, so no need to check
+            return func(interp, *args, **kwargs)
+
+        # Check that it uses the same coordinates as the interpolator's SparseFunction
+        subfuncs = {getattr(sfunc, s, None) for s in sfunc._sub_functions}
+        for f in a_sfuncs:
+            for s in f._sub_functions:
+                if getattr(f, s, None) not in subfuncs:
+                    raise ValueError(f"Interpolation/injection with {sfunc}"
+                                     f"requires {f} "
+                                     f"to use the same {s} as {sfunc}")
+
+        return func(interp, *args, **kwargs)
+    return wrapper
+
+
 def _extract_subdomain(variables):
     """
     Check if any of the variables provided are defined on a SubDomain
@@ -322,6 +350,7 @@ def _interp_idx(self, variables, implicit_dims=None, pos_only=(), subdomain=None
         return idx_subs, temps
 
     @check_radius
+    @check_coords
     def interpolate(self, expr, increment=False, self_subs=None, implicit_dims=None):
         """
         Generate equations interpolating an arbitrary expression into ``self``.
@@ -342,6 +371,7 @@ def interpolate(self, expr, increment=False, self_subs=None, implicit_dims=None)
         return Interpolation(expr, increment, implicit_dims, self_subs, self)
 
     @check_radius
+    @check_coords
     def inject(self, field, expr, implicit_dims=None):
         """
         Generate equations injecting an arbitrary expression into a field.

devito/operator/operator.py

@@ -647,7 +647,8 @@ def _prepare_arguments(self, autotune=None, estimate_memory=False, **kwargs):
                 else:
                     args[k] = args.unique(k, candidate=v)
 
-        kwargs['args'] = args.reduce_inplace()
+        args.reduce_inplace()
+        kwargs['args'] = args
 
         for i in discretizations:
             args.update(i._arg_values(**kwargs))

devito/tools/data_structures.py

@@ -223,8 +223,6 @@ def reduce_inplace(self):
         for k, v in self.reduce_all().items():
             self[k] = v
 
-        return self
-
 
 class DefaultOrderedDict(OrderedDict):
     # Source: http://stackoverflow.com/a/6190500/562769

tests/test_interpolation.py

@@ -1255,3 +1255,18 @@ def test_inject_subdomain_mpi(self, mode):
             assert data1 == None  # noqa
             assert data2 == None  # noqa
             assert data3 == None  # noqa
+
+
+def test_wrong_coords():
+    grid = Grid(shape=(11, 11))
+    s = SparseFunction(name='src', npoint=1, grid=grid)
+    s2 = SparseFunction(name='src2', npoint=1, grid=grid)
+    u = Function(name='u', grid=grid)
+
+    with pytest.raises(ValueError) as vinfo:
+        s.inject(u, expr=s2)
+    assert "Interpolation/injection with" in str(vinfo.value)
+
+    with pytest.raises(ValueError) as vinfo:
+        s.interpolate(u + s2)
+    assert "Interpolation/injection with" in str(vinfo.value)