Mercurial > hg > vamp-build-and-test
diff DEPENDENCIES/mingw32/Python27/Lib/site-packages/numpy/ma/__init__.py @ 87:2a2c65a20a8b
Add Python libs and headers
author | Chris Cannam |
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date | Wed, 25 Feb 2015 14:05:22 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DEPENDENCIES/mingw32/Python27/Lib/site-packages/numpy/ma/__init__.py Wed Feb 25 14:05:22 2015 +0000 @@ -0,0 +1,58 @@ +""" +============= +Masked Arrays +============= + +Arrays sometimes contain invalid or missing data. When doing operations +on such arrays, we wish to suppress invalid values, which is the purpose masked +arrays fulfill (an example of typical use is given below). + +For example, examine the following array: + +>>> x = np.array([2, 1, 3, np.nan, 5, 2, 3, np.nan]) + +When we try to calculate the mean of the data, the result is undetermined: + +>>> np.mean(x) +nan + +The mean is calculated using roughly ``np.sum(x)/len(x)``, but since +any number added to ``NaN`` [1]_ produces ``NaN``, this doesn't work. Enter +masked arrays: + +>>> m = np.ma.masked_array(x, np.isnan(x)) +>>> m +masked_array(data = [2.0 1.0 3.0 -- 5.0 2.0 3.0 --], + mask = [False False False True False False False True], + fill_value=1e+20) + +Here, we construct a masked array that suppress all ``NaN`` values. We +may now proceed to calculate the mean of the other values: + +>>> np.mean(m) +2.6666666666666665 + +.. [1] Not-a-Number, a floating point value that is the result of an + invalid operation. + +""" +from __future__ import division, absolute_import, print_function + +__author__ = "Pierre GF Gerard-Marchant ($Author: jarrod.millman $)" +__version__ = '1.0' +__revision__ = "$Revision: 3473 $" +__date__ = '$Date: 2007-10-29 17:18:13 +0200 (Mon, 29 Oct 2007) $' + +from . import core +from .core import * + +from . import extras +from .extras import * + +__all__ = ['core', 'extras'] +__all__ += core.__all__ +__all__ += extras.__all__ + +from numpy.testing import Tester +test = Tester().test +bench = Tester().bench