Merge pull request numpy#5302 from idfah/master

Fixed meshgrid to return arrays with same dtype as arguments.

numpy/lib/function_base.py

@@ -4530,18 +4530,14 @@ def meshgrid(*xi, **kwargs):
         output[1].shape = (-1, 1) + (1,)*(ndim - 2)
         shape[0], shape[1] = shape[1], shape[0]
 
-    if sparse:
-        if copy_:
-            return [x.copy() for x in output]
-        else:
-            return output
-    else:
+    if copy_:
+        output = [x.copy() for x in output]
+
+    if not sparse and len(output) > 0:
         # Return the full N-D matrix (not only the 1-D vector)
-        if copy_:
-            mult_fact = np.ones(shape, dtype=int)
-            return [x * mult_fact for x in output]
-        else:
-            return np.broadcast_arrays(*output)
+        output = np.broadcast_arrays(*output, subok=True)
+
+    return output
 
 
 def delete(arr, obj, axis=None):

numpy/lib/tests/test_function_base.py

@@ -2211,6 +2211,7 @@ def test_single_input(self):
     def test_no_input(self):
         args = []
         assert_array_equal([], meshgrid(*args))
+        assert_array_equal([], meshgrid(*args, copy=False))
 
     def test_indexing(self):
         x = [1, 2, 3]
@@ -2244,6 +2245,30 @@ def test_invalid_arguments(self):
         assert_raises(TypeError, meshgrid,
                       [1, 2, 3], [4, 5, 6, 7], indices='ij')
 
+    def test_return_type(self):
+        # Test for appropriate dtype in returned arrays.
+        # Regression test for issue #5297
+        # https://github.com/numpy/numpy/issues/5297
+        x = np.arange(0, 10, dtype=np.float32)
+        y = np.arange(10, 20, dtype=np.float64)
+
+        X, Y = np.meshgrid(x,y)
+
+        assert_(X.dtype == x.dtype)
+        assert_(Y.dtype == y.dtype)
+
+        # copy
+        X, Y = np.meshgrid(x,y, copy=True)
+
+        assert_(X.dtype == x.dtype)
+        assert_(Y.dtype == y.dtype)
+
+        # sparse
+        X, Y = np.meshgrid(x,y, sparse=True)
+
+        assert_(X.dtype == x.dtype)
+        assert_(Y.dtype == y.dtype)
+
 
 class TestPiecewise(TestCase):