Fixes issue #403.

Author: Kurt Smith

distarray/dist/tests/test_distarray.py

@@ -722,6 +722,22 @@ def test_create_target_subset(self):
         self.assertEqual(len(ddpr), len(subtargets))
 
 
+class TestReductionRegression(ContextTestCase):
+    ''' Separate class necessary b/c need to run on at least 9 engines to exercise
+    regression.
+
+    '''
+
+    ntargets = 9
+
+    def test_reduction(self):
+        """ Tests that GH issue 403 is fixed """
+        arr = numpy.arange(9 * 9).reshape(9, 9)
+        dist = Distribution(self.context, arr.shape, ('b', 'b'), (9, 1))
+        darr = self.context.fromndarray(arr, dist)
+        assert_allclose(darr.sum().tondarray(), arr.sum())
+
+
 class TestReduceMethods(ContextTestCase):
     """Test reduction methods"""
 

distarray/local/localarray.py

@@ -954,7 +954,8 @@ def _basic_reducer(reduce_comm, op, func, args, kwargs, out):
         out_ndarray = out.ndarray
         if out.ndarray.dtype == np.bool:
             out.ndarray.dtype = np.uint8
-    local_reduce = func(*args, **kwargs)
+    # Use asarray() to coerce np scalars to zero-dimensional arrays.
+    local_reduce = np.asarray(func(*args, **kwargs))
     reduce_comm.Reduce(local_reduce, out_ndarray, op=op, root=0)
     return out