ENH: deprecate bias and ddof arguments to corrcoef

The bias and ddof arguments had no effect on the calculation of the
correlation coefficient because the value cancels in the calculation.

Deprecate these arguments to np.corrcoef and np.ma.corrcoef.

1 files changed, 10 insertions, 5 deletions

diff --git a/numpy/ma/tests/test_regression.py b/numpy/ma/tests/test_regression.py
index 7b32199ea..dba74d357 100644
--- a/numpy/ma/tests/test_regression.py
+++ b/numpy/ma/tests/test_regression.py
@@ -1,7 +1,10 @@
 from __future__ import division, absolute_import, print_function
 
+import warnings
+
 import numpy as np
-from numpy.testing import *
+from numpy.testing import (assert_, TestCase, assert_array_equal,
+                           assert_allclose, run_module_suite)
 from numpy.compat import sixu
 
 rlevel = 1
@@ -66,10 +69,12 @@ class TestRegression(TestCase):
         # See gh-3336
         x = np.ma.masked_equal([1, 2, 3, 4, 5], 4)
         y = np.array([2, 2.5, 3.1, 3, 5])
-        r0 = np.ma.corrcoef(x, y, ddof=0)
-        r1 = np.ma.corrcoef(x, y, ddof=1)
-        # ddof should not have an effect (it gets cancelled out)
-        assert_allclose(r0.data, r1.data)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            r0 = np.ma.corrcoef(x, y, ddof=0)
+            r1 = np.ma.corrcoef(x, y, ddof=1)
+            # ddof should not have an effect (it gets cancelled out)
+            assert_allclose(r0.data, r1.data)
 
 if __name__ == "__main__":
     run_module_suite()