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author | pierregm <pierregm@localhost> | 2009-01-09 20:18:12 +0000 |
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committer | pierregm <pierregm@localhost> | 2009-01-09 20:18:12 +0000 |
commit | 7dfb0e620c2545c7860c05a66abc1b2429f8e415 (patch) | |
tree | b48944d2761213801d36496f92a14a7928270ebd /numpy/ma/core.py | |
parent | fbf902ca2bf3f119b4d7b77833e4a3bc70c5101e (diff) | |
download | numpy-7dfb0e620c2545c7860c05a66abc1b2429f8e415.tar.gz |
* Added flatten_structured_arrays
* Fixed _get_recordarray for nested structures
Diffstat (limited to 'numpy/ma/core.py')
-rw-r--r-- | numpy/ma/core.py | 76 |
1 files changed, 60 insertions, 16 deletions
diff --git a/numpy/ma/core.py b/numpy/ma/core.py index 76982f5ef..cafe78b4d 100644 --- a/numpy/ma/core.py +++ b/numpy/ma/core.py @@ -1483,6 +1483,56 @@ class FlatIter(object): return d +def flatten_structured_array(a): + """ + Flatten a strutured array. + + The datatype of the output is the largest datatype of the (nested) fields. + + Returns + ------- + output : var + Flatten MaskedArray if the input is a MaskedArray, + standard ndarray otherwise. + + Examples + -------- + >>> ndtype = [('a', int), ('b', float)] + >>> a = np.array([(1, 1), (2, 2)], dtype=ndtype) + >>> flatten_structured_array(a) + array([[1., 1.], + [2., 2.]]) + + """ + # + def flatten_sequence(iterable): + """Flattens a compound of nested iterables.""" + for elm in iter(iterable): + if hasattr(elm,'__iter__'): + for f in flatten_sequence(elm): + yield f + else: + yield elm + # + a = np.asanyarray(a) + inishape = a.shape + a = a.ravel() + if isinstance(a, MaskedArray): + out = np.array([tuple(flatten_sequence(d.item())) for d in a._data]) + out = out.view(MaskedArray) + out._mask = np.array([tuple(flatten_sequence(d.item())) + for d in getmaskarray(a)]) + else: + out = np.array([tuple(flatten_sequence(d.item())) for d in a]) + if len(inishape) > 1: + newshape = list(out.shape) + newshape[0] = inishape + out.shape = tuple(flatten_sequence(newshape)) + return out + + + + class MaskedArray(ndarray): """ Arrays with possibly masked values. Masked values of True @@ -2021,34 +2071,28 @@ class MaskedArray(ndarray): # return self._mask.reshape(self.shape) return self._mask mask = property(fget=_get_mask, fset=__setmask__, doc="Mask") - # - def _getrecordmask(self): - """Return the mask of the records. + + + def _get_recordmask(self): + """ + Return the mask of the records. A record is masked when all the fields are masked. """ _mask = ndarray.__getattribute__(self, '_mask').view(ndarray) if _mask.dtype.names is None: return _mask - if _mask.size > 1: - axis = 1 - else: - axis = None - # - try: - return _mask.view((bool_, len(self.dtype))).all(axis) - except ValueError: - # In case we have nested fields... - return np.all([[f[n].all() for n in _mask.dtype.names] - for f in _mask], axis=axis) + return np.all(flatten_structured_array(_mask), axis=-1) + - def _setrecordmask(self): + def _set_recordmask(self): """Return the mask of the records. A record is masked when all the fields are masked. """ raise NotImplementedError("Coming soon: setting the mask per records!") - recordmask = property(fget=_getrecordmask) + recordmask = property(fget=_get_recordmask) + #............................................ def harden_mask(self): """Force the mask to hard. |