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| author | blackhao <13851610112@163.com> | 2025-08-22 02:51:50 -0500 |
|---|---|---|
| committer | blackhao <13851610112@163.com> | 2025-08-22 02:51:50 -0500 |
| commit | 4aab4087dc97906d0b9890035401175cdaab32d4 (patch) | |
| tree | 4e2e9d88a711ec5b1cfa02e8ac72a55183b99123 /.venv/lib/python3.12/site-packages/numpy/ma/__init__.py | |
| parent | afa8f50d1d21c721dabcb31ad244610946ab65a3 (diff) | |
2.0
Diffstat (limited to '.venv/lib/python3.12/site-packages/numpy/ma/__init__.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/numpy/ma/__init__.py | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/numpy/ma/__init__.py b/.venv/lib/python3.12/site-packages/numpy/ma/__init__.py new file mode 100644 index 0000000..e2a742e --- /dev/null +++ b/.venv/lib/python3.12/site-packages/numpy/ma/__init__.py @@ -0,0 +1,53 @@ +""" +============= +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. + +.. moduleauthor:: Pierre Gerard-Marchant +.. moduleauthor:: Jarrod Millman + +""" +from . import core, extras +from .core import * +from .extras import * + +__all__ = ['core', 'extras'] +__all__ += core.__all__ +__all__ += extras.__all__ + +from numpy._pytesttester import PytestTester + +test = PytestTester(__name__) +del PytestTester |
