Merge pull request #5002 from juliantaylor/convolve-nocopy

ENH: remove unnecessary copy of convolve inputs

2 files changed, 21 insertions, 1 deletions

diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py
index 5d7407ce0..efd8af45d 100644
--- a/numpy/core/numeric.py
+++ b/numpy/core/numeric.py
@@ -985,7 +985,7 @@ def convolve(a,v,mode='full'):
     array([ 2.5])
 
     """
-    a, v = array(a, ndmin=1), array(v, ndmin=1)
+    a, v = array(a, copy=False, ndmin=1), array(v, copy=False, ndmin=1)
     if (len(v) > len(a)):
         a, v = v, a
     if len(a) == 0 :
diff --git a/numpy/core/tests/test_numeric.py b/numpy/core/tests/test_numeric.py
index 483484467..3dea80d14 100644
--- a/numpy/core/tests/test_numeric.py
+++ b/numpy/core/tests/test_numeric.py
@@ -1920,6 +1920,13 @@ class _TestCorrelate(TestCase):
         z = np.correlate(self.y, self.x, 'full', old_behavior=self.old_behavior)
         assert_array_almost_equal(z, self.z2)
 
+    def test_no_overwrite(self):
+        d = np.ones(100)
+        k = np.ones(3)
+        np.correlate(d, k)
+        assert_array_equal(d, np.ones(100))
+        assert_array_equal(k, np.ones(3))
+
 class TestCorrelate(_TestCorrelate):
     old_behavior = True
     def _setup(self, dt):
@@ -1958,6 +1965,19 @@ class TestCorrelateNew(_TestCorrelate):
         z = np.correlate(y, x, 'full', old_behavior=self.old_behavior)
         assert_array_almost_equal(z, r_z)
 
+class TestConvolve(TestCase):
+    def test_object(self):
+        d = [1.] * 100
+        k = [1.] * 3
+        assert_array_almost_equal(np.convolve(d, k)[2:-2], np.full(98, 3))
+
+    def test_no_overwrite(self):
+        d = np.ones(100)
+        k = np.ones(3)
+        np.convolve(d, k)
+        assert_array_equal(d, np.ones(100))
+        assert_array_equal(k, np.ones(3))
+
 class TestArgwhere(object):
     def test_2D(self):
         x = np.arange(6).reshape((2, 3))