Python ma.masked方法代码示例

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_exotic_formats(self):
        # Test that 'exotic' formats are processed properly
        easy = mrecarray(1, dtype=[('i', int), ('s', '|S8'), ('f', float)])
        easy[0] = masked
        assert_equal(easy.filled(1).item(), (1, asbytes('1'), 1.))

        solo = mrecarray(1, dtype=[('f0', '<f8', (2, 2))])
        solo[0] = masked
        assert_equal(solo.filled(1).item(),
                     np.array((1,), dtype=solo.dtype).item())

        mult = mrecarray(2, dtype="i4, (2,3)float, float")
        mult[0] = masked
        mult[1] = (1, 1, 1)
        mult.filled(0)
        assert_equal_records(mult.filled(0),
                             np.array([(0, 0, 0), (1, 1, 1)],
                                      dtype=mult.dtype)) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_set_mask(self):
        base = self.base.copy()
        mbase = base.view(mrecarray)
        # Set the mask to True .......................
        mbase.mask = masked
        assert_equal(ma.getmaskarray(mbase['b']), [1]*5)
        assert_equal(mbase['a']._mask, mbase['b']._mask)
        assert_equal(mbase['a']._mask, mbase['c']._mask)
        assert_equal(mbase._mask.tolist(),
                     np.array([(1, 1, 1)]*5, dtype=bool))
        # Delete the mask ............................
        mbase.mask = nomask
        assert_equal(ma.getmaskarray(mbase['c']), [0]*5)
        assert_equal(mbase._mask.tolist(),
                     np.array([(0, 0, 0)]*5, dtype=bool))
    # 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def _parse_args(*args):
    X, Y, U, V, C = [None] * 5
    args = list(args)

    # The use of atleast_1d allows for handling scalar arguments while also
    # keeping masked arrays
    if len(args) == 3 or len(args) == 5:
        C = np.atleast_1d(args.pop(-1))
    V = np.atleast_1d(args.pop(-1))
    U = np.atleast_1d(args.pop(-1))
    if U.ndim == 1:
        nr, nc = 1, U.shape[0]
    else:
        nr, nc = U.shape
    if len(args) == 2:  # remaining after removing U,V,C
        X, Y = [np.array(a).ravel() for a in args]
        if len(X) == nc and len(Y) == nr:
            X, Y = [a.ravel() for a in np.meshgrid(X, Y)]
    else:
        indexgrid = np.meshgrid(np.arange(nc), np.arange(nr))
        X, Y = [np.ravel(a) for a in indexgrid]
    return X, Y, U, V, C 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def trim(a, limits=None, inclusive=(True,True), relative=False, axis=None):
    """
    Trims an array by masking the data outside some given limits.

    Returns a masked version of the input array.

    %s

    Examples
    --------
    >>> z = [ 1, 2, 3, 4, 5, 6, 7, 8, 9,10]
    >>> trim(z,(3,8))
    [--,--, 3, 4, 5, 6, 7, 8,--,--]
    >>> trim(z,(0.1,0.2),relative=True)
    [--, 2, 3, 4, 5, 6, 7, 8,--,--]

    """
    if relative:
        return trimr(a, limits=limits, inclusive=inclusive, axis=axis)
    else:
        return trima(a, limits=limits, inclusive=inclusive) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def kurtosis(a, axis=0, fisher=True, bias=True):
    a, axis = _chk_asarray(a, axis)
    m2 = moment(a,2,axis)
    m4 = moment(a,4,axis)
    olderr = np.seterr(all='ignore')
    try:
        vals = ma.where(m2 == 0, 0, m4 / m2**2.0)
    finally:
        np.seterr(**olderr)

    if not bias:
        n = a.count(axis)
        can_correct = (n > 3) & (m2 is not ma.masked and m2 > 0)
        if can_correct.any():
            n = np.extract(can_correct, n)
            m2 = np.extract(can_correct, m2)
            m4 = np.extract(can_correct, m4)
            nval = 1.0/(n-2)/(n-3)*((n*n-1.0)*m4/m2**2.0-3*(n-1)**2.0)
            np.place(vals, can_correct, nval+3.0)
    if fisher:
        return vals - 3
    else:
        return vals 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_get(self):
        # Tests fields retrieval
        base = self.base.copy()
        mbase = base.view(mrecarray)
        # As fields..........
        for field in ('a', 'b', 'c'):
            assert_equal(getattr(mbase, field), mbase[field])
            assert_equal(base[field], mbase[field])
        # as elements .......
        mbase_first = mbase[0]
        assert_(isinstance(mbase_first, mrecarray))
        assert_equal(mbase_first.dtype, mbase.dtype)
        assert_equal(mbase_first.tolist(), (1, 1.1, b'one'))
        # Used to be mask, now it's recordmask
        assert_equal(mbase_first.recordmask, nomask)
        assert_equal(mbase_first._mask.item(), (False, False, False))
        assert_equal(mbase_first['a'], mbase['a'][0])
        mbase_last = mbase[-1]
        assert_(isinstance(mbase_last, mrecarray))
        assert_equal(mbase_last.dtype, mbase.dtype)
        assert_equal(mbase_last.tolist(), (None, None, None))
        # Used to be mask, now it's recordmask
        assert_equal(mbase_last.recordmask, True)
        assert_equal(mbase_last._mask.item(), (True, True, True))
        assert_equal(mbase_last['a'], mbase['a'][-1])
        assert_((mbase_last['a'] is masked))
        # as slice ..........
        mbase_sl = mbase[:2]
        assert_(isinstance(mbase_sl, mrecarray))
        assert_equal(mbase_sl.dtype, mbase.dtype)
        # Used to be mask, now it's recordmask
        assert_equal(mbase_sl.recordmask, [0, 1])
        assert_equal_records(mbase_sl.mask,
                             np.array([(False, False, False),
                                       (True, True, True)],
                                      dtype=mbase._mask.dtype))
        assert_equal_records(mbase_sl, base[:2].view(mrecarray))
        for field in ('a', 'b', 'c'):
            assert_equal(getattr(mbase_sl, field), base[:2][field]) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_set_fields_mask(self):
        # Tests setting the mask of a field.
        base = self.base.copy()
        # This one has already a mask....
        mbase = base.view(mrecarray)
        mbase['a'][-2] = masked
        assert_equal(mbase.a, [1, 2, 3, 4, 5])
        assert_equal(mbase.a._mask, [0, 1, 0, 1, 1])
        # This one has not yet
        mbase = fromarrays([np.arange(5), np.random.rand(5)],
                           dtype=[('a', int), ('b', float)])
        mbase['a'][-2] = masked
        assert_equal(mbase.a, [0, 1, 2, 3, 4])
        assert_equal(mbase.a._mask, [0, 0, 0, 1, 0]) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_set_mask(self):
        base = self.base.copy()
        mbase = base.view(mrecarray)
        # Set the mask to True .......................
        mbase.mask = masked
        assert_equal(ma.getmaskarray(mbase['b']), [1]*5)
        assert_equal(mbase['a']._mask, mbase['b']._mask)
        assert_equal(mbase['a']._mask, mbase['c']._mask)
        assert_equal(mbase._mask.tolist(),
                     np.array([(1, 1, 1)]*5, dtype=bool))
        # Delete the mask ............................
        mbase.mask = nomask
        assert_equal(ma.getmaskarray(mbase['c']), [0]*5)
        assert_equal(mbase._mask.tolist(),
                     np.array([(0, 0, 0)]*5, dtype=bool)) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_set_elements(self):
        base = self.base.copy()
        # Set an element to mask .....................
        mbase = base.view(mrecarray).copy()
        mbase[-2] = masked
        assert_equal(
            mbase._mask.tolist(),
            np.array([(0, 0, 0), (1, 1, 1), (0, 0, 0), (1, 1, 1), (1, 1, 1)],
                     dtype=bool))
        # Used to be mask, now it's recordmask!
        assert_equal(mbase.recordmask, [0, 1, 0, 1, 1])
        # Set slices .................................
        mbase = base.view(mrecarray).copy()
        mbase[:2] = (5, 5, 5)
        assert_equal(mbase.a._data, [5, 5, 3, 4, 5])
        assert_equal(mbase.a._mask, [0, 0, 0, 0, 1])
        assert_equal(mbase.b._data, [5., 5., 3.3, 4.4, 5.5])
        assert_equal(mbase.b._mask, [0, 0, 0, 0, 1])
        assert_equal(mbase.c._data,
                     [b'5', b'5', b'three', b'four', b'five'])
        assert_equal(mbase.b._mask, [0, 0, 0, 0, 1])

        mbase = base.view(mrecarray).copy()
        mbase[:2] = masked
        assert_equal(mbase.a._data, [1, 2, 3, 4, 5])
        assert_equal(mbase.a._mask, [1, 1, 0, 0, 1])
        assert_equal(mbase.b._data, [1.1, 2.2, 3.3, 4.4, 5.5])
        assert_equal(mbase.b._mask, [1, 1, 0, 0, 1])
        assert_equal(mbase.c._data,
                     [b'one', b'two', b'three', b'four', b'five'])
        assert_equal(mbase.b._mask, [1, 1, 0, 0, 1]) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_view_simple_dtype(self):
        (mrec, a, b, arr) = self.data
        ntype = (float, 2)
        test = mrec.view(ntype)
        assert_(isinstance(test, ma.MaskedArray))
        assert_equal(test, np.array(list(zip(a, b)), dtype=float))
        assert_(test[3, 1] is ma.masked) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def test_view_flexible_type(self):
        (mrec, a, b, arr) = self.data
        alttype = [('A', float), ('B', float)]
        test = mrec.view(alttype)
        assert_(isinstance(test, MaskedRecords))
        assert_equal_records(test, arr.view(alttype))
        assert_(test['B'][3] is masked)
        assert_equal(test.dtype, np.dtype(alttype))
        assert_(test._fill_value is None)


############################################################################## 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def _chk_asarray(a, axis):
    # Always returns a masked array, raveled for axis=None
    a = ma.asanyarray(a)
    if axis is None:
        a = ma.ravel(a)
        outaxis = 0
    else:
        outaxis = axis
    return a, outaxis 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def argstoarray(*args):
    """
    Constructs a 2D array from a group of sequences.

    Sequences are filled with missing values to match the length of the longest
    sequence.

    Parameters
    ----------
    args : sequences
        Group of sequences.

    Returns
    -------
    argstoarray : MaskedArray
        A ( `m` x `n` ) masked array, where `m` is the number of arguments and
        `n` the length of the longest argument.

    Notes
    -----
    `numpy.ma.row_stack` has identical behavior, but is called with a sequence
    of sequences.

    """
    if len(args) == 1 and not isinstance(args[0], ndarray):
        output = ma.asarray(args[0])
        if output.ndim != 2:
            raise ValueError("The input should be 2D")
    else:
        n = len(args)
        m = max([len(k) for k in args])
        output = ma.array(np.empty((n,m), dtype=float), mask=True)
        for (k,v) in enumerate(args):
            output[k,:len(v)] = v

    output[np.logical_not(np.isfinite(output._data))] = masked
    return output 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def msign(x):
    """Returns the sign of x, or 0 if x is masked."""
    return ma.filled(np.sign(x), 0) 

# 需要导入模块: from numpy import ma [as 别名]
# 或者: from numpy.ma import masked [as 别名]
def linregress(x, y=None):
    """
    Linear regression calculation

    Note that the non-masked version is used, and that this docstring is
    replaced by the non-masked docstring + some info on missing data.

    """
    if y is None:
        x = ma.array(x)
        if x.shape[0] == 2:
            x, y = x
        elif x.shape[1] == 2:
            x, y = x.T
        else:
            msg = ("If only `x` is given as input, it has to be of shape "
                   "(2, N) or (N, 2), provided shape was %s" % str(x.shape))
            raise ValueError(msg)
    else:
        x = ma.array(x)
        y = ma.array(y)

    x = x.flatten()
    y = y.flatten()

    m = ma.mask_or(ma.getmask(x), ma.getmask(y), shrink=False)
    if m is not nomask:
        x = ma.array(x, mask=m)
        y = ma.array(y, mask=m)
        if np.any(~m):
            slope, intercept, r, prob, sterrest = stats_linregress(x.data[~m],
                                                                   y.data[~m])
        else:
            # All data is masked
            return None, None, None, None, None
    else:
        slope, intercept, r, prob, sterrest = stats_linregress(x.data, y.data)

    return LinregressResult(slope, intercept, r, prob, sterrest)