diff options
| -rw-r--r-- | numpy/core/numeric.py | 37 | ||||
| -rw-r--r-- | numpy/core/tests/test_numeric.py | 2 |
2 files changed, 14 insertions, 25 deletions
diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py index 8c9f507d2..dbad73cfe 100644 --- a/numpy/core/numeric.py +++ b/numpy/core/numeric.py @@ -640,16 +640,17 @@ def _mode_from_name(mode): return _mode_from_name_dict[mode.lower()[0]] return mode -def correlate(a,v,mode='valid',old_behavior=True): +def correlate(a, v, mode='valid', old_behavior=False): """ - Discrete, linear correlation of two 1-dimensional sequences. + Cross-correlation of two 1-dimensional sequences. - This function is equivalent to + This function computes the correlation as generally defined in signal + processing texts:: - >>> np.convolve(a, v[::-1], mode=mode) - ... #doctest: +SKIP + z[k] = sum_n a[n] * conj(v[n+k]) - where ``v[::-1]`` is the reverse of `v`. + with a and v sequences being zero-padded where necessary and conj being + the conjugate. Parameters ---------- @@ -659,27 +660,13 @@ def correlate(a,v,mode='valid',old_behavior=True): Refer to the `convolve` docstring. Note that the default is `valid`, unlike `convolve`, which uses `full`. old_behavior : bool - If True, uses the old, numeric behavior (correlate(a,v) == correlate(v, + If True, uses the old behavior from Numeric, (correlate(a,v) == correlate(v, a), and the conjugate is not taken for complex arrays). If False, uses the conventional signal processing definition (see note). See Also -------- - convolve : Discrete, linear convolution of two - one-dimensional sequences. - acorrelate : Discrete correlation following the usual signal processing - definition for complex arrays, and without assuming that - ``correlate(a, b) == correlate(b, a)``. - - Notes - ----- - If `old_behavior` is False, this function computes the correlation as - generally defined in signal processing texts:: - - z[k] = sum_n a[n] * conj(v[n+k]) - - with a and v sequences being zero-padded where necessary and conj being - the conjugate. + convolve : Discrete, linear convolution of two one-dimensional sequences. Examples -------- @@ -692,10 +679,12 @@ def correlate(a,v,mode='valid',old_behavior=True): """ mode = _mode_from_name(mode) +# the old behavior should be made available under a different name, see thread +# http://thread.gmane.org/gmane.comp.python.numeric.general/12609/focus=12630 if old_behavior: warnings.warn(""" -The current behavior of correlate is deprecated for 1.4.0, and will be removed -for NumPy 1.5.0. +The old behavior of correlate was deprecated for 1.4.0, and will be completely removed +for NumPy 2.0. The new behavior fits the conventional definition of correlation: inputs are never swapped, and the second argument is conjugated for complex arrays.""", diff --git a/numpy/core/tests/test_numeric.py b/numpy/core/tests/test_numeric.py index f1fa783bb..e89c2a3f5 100644 --- a/numpy/core/tests/test_numeric.py +++ b/numpy/core/tests/test_numeric.py @@ -938,7 +938,7 @@ class TestCorrelate(_TestCorrelate): x = np.array([1, 2, 3, 4+1j], dtype=np.complex) y = np.array([-1, -2j, 3+1j], dtype=np.complex) r_z = np.array([3+1j, 6, 8-1j, 9+1j, -1-8j, -4-1j], dtype=np.complex) - z = np.correlate(x, y, 'full') + z = np.correlate(x, y, 'full', old_behavior=self.old_behavior) assert_array_almost_equal(z, r_z) @dec.deprecated() |