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| author | Sebastian Berg <sebastian@sipsolutions.net> | 2013-05-16 18:06:30 +0200 |
|---|---|---|
| committer | Sebastian Berg <sebastian@sipsolutions.net> | 2013-05-17 11:40:08 +0200 |
| commit | 4c291f361fdc8c756e6b1cd7ff7ce2c2ddfc5ed9 (patch) | |
| tree | c7366265c94002149c6455fad4bbabece056c56b | |
| parent | 44a796154a4d349768c6e2244b39e8a69d2d1680 (diff) | |
| download | numpy-4c291f361fdc8c756e6b1cd7ff7ce2c2ddfc5ed9.tar.gz | |
BUG: Correctly pass on ddof paramter on inside np.ma.corrcoef
While ddof has basically no effect on corrcoef, it exists,
but it was not passed on correctly (instead only bias would
be passed on). Fixes gh-3336
| -rw-r--r-- | numpy/ma/extras.py | 7 | ||||
| -rw-r--r-- | numpy/ma/tests/test_regression.py | 8 |
2 files changed, 11 insertions, 4 deletions
diff --git a/numpy/ma/extras.py b/numpy/ma/extras.py index 2f3159c49..5a484ce9d 100644 --- a/numpy/ma/extras.py +++ b/numpy/ma/extras.py @@ -1402,14 +1402,13 @@ def corrcoef(x, y=None, rowvar=True, bias=False, allow_masked=True, ddof=None): if rowvar: for i in range(n - 1): for j in range(i + 1, n): - _x = mask_cols(vstack((x[i], x[j]))).var(axis=1, - ddof=1 - bias) + _x = mask_cols(vstack((x[i], x[j]))).var(axis=1, ddof=ddof) _denom[i, j] = _denom[j, i] = ma.sqrt(ma.multiply.reduce(_x)) else: for i in range(n - 1): for j in range(i + 1, n): - _x = mask_cols(vstack((x[:, i], x[:, j]))).var(axis=1, - ddof=1 - bias) + _x = mask_cols( + vstack((x[:, i], x[:, j]))).var(axis=1, ddof=ddof) _denom[i, j] = _denom[j, i] = ma.sqrt(ma.multiply.reduce(_x)) return c / _denom diff --git a/numpy/ma/tests/test_regression.py b/numpy/ma/tests/test_regression.py index f713a8a1a..eb301aa05 100644 --- a/numpy/ma/tests/test_regression.py +++ b/numpy/ma/tests/test_regression.py @@ -61,6 +61,14 @@ class TestRegression(TestCase): a.var(out=mout) assert_(mout._data == 0) + def test_ddof_corrcoef(self): + # 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) if __name__ == "__main__": run_module_suite() |