Python numeric.shape方法代码示例

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def _replace_zero_by_x_arrays(sub_arys):
    for i in range(len(sub_arys)):
        if _nx.ndim(sub_arys[i]) == 0:
            sub_arys[i] = _nx.empty(0, dtype=sub_arys[i].dtype)
        elif _nx.sometrue(_nx.equal(_nx.shape(sub_arys[i]), 0)):
            sub_arys[i] = _nx.empty(0, dtype=sub_arys[i].dtype)
    return sub_arys 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def _replace_zero_by_x_arrays(sub_arys):
    for i in range(len(sub_arys)):
        if len(_nx.shape(sub_arys[i])) == 0:
            sub_arys[i] = _nx.empty(0, dtype=sub_arys[i].dtype)
        elif _nx.sometrue(_nx.equal(_nx.shape(sub_arys[i]), 0)):
            sub_arys[i] = _nx.empty(0, dtype=sub_arys[i].dtype)
    return sub_arys 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def _replace_zero_by_x_arrays(sub_arys):
    for i in range(len(sub_arys)):
        if len(_nx.shape(sub_arys[i])) == 0:
            sub_arys[i] = _nx.array([])
        elif _nx.sometrue(_nx.equal(_nx.shape(sub_arys[i]), 0)):
            sub_arys[i] = _nx.array([])
    return sub_arys 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def dstack(tup):
    """
    Stack arrays in sequence depth wise (along third axis).

    This is equivalent to concatenation along the third axis after 2-D arrays
    of shape `(M,N)` have been reshaped to `(M,N,1)` and 1-D arrays of shape
    `(N,)` have been reshaped to `(1,N,1)`. Rebuilds arrays divided by
    `dsplit`.

    This function makes most sense for arrays with up to 3 dimensions. For
    instance, for pixel-data with a height (first axis), width (second axis),
    and r/g/b channels (third axis). The functions `concatenate`, `stack` and
    `block` provide more general stacking and concatenation operations.

    Parameters
    ----------
    tup : sequence of arrays
        The arrays must have the same shape along all but the third axis.
        1-D or 2-D arrays must have the same shape.

    Returns
    -------
    stacked : ndarray
        The array formed by stacking the given arrays, will be at least 3-D.

    See Also
    --------
    stack : Join a sequence of arrays along a new axis.
    vstack : Stack along first axis.
    hstack : Stack along second axis.
    concatenate : Join a sequence of arrays along an existing axis.
    dsplit : Split array along third axis.

    Examples
    --------
    >>> a = np.array((1,2,3))
    >>> b = np.array((2,3,4))
    >>> np.dstack((a,b))
    array([[[1, 2],
            [2, 3],
            [3, 4]]])

    >>> a = np.array([[1],[2],[3]])
    >>> b = np.array([[2],[3],[4]])
    >>> np.dstack((a,b))
    array([[[1, 2]],
           [[2, 3]],
           [[3, 4]]])

    """
    _warn_for_nonsequence(tup)
    return _nx.concatenate([atleast_3d(_m) for _m in tup], 2) 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def array_split(ary, indices_or_sections, axis=0):
    """
    Split an array into multiple sub-arrays.

    Please refer to the ``split`` documentation.  The only difference
    between these functions is that ``array_split`` allows
    `indices_or_sections` to be an integer that does *not* equally
    divide the axis. For an array of length l that should be split
    into n sections, it returns l % n sub-arrays of size l//n + 1
    and the rest of size l//n.

    See Also
    --------
    split : Split array into multiple sub-arrays of equal size.

    Examples
    --------
    >>> x = np.arange(8.0)
    >>> np.array_split(x, 3)
        [array([ 0.,  1.,  2.]), array([ 3.,  4.,  5.]), array([ 6.,  7.])]

    >>> x = np.arange(7.0)
    >>> np.array_split(x, 3)
        [array([ 0.,  1.,  2.]), array([ 3.,  4.]), array([ 5.,  6.])]

    """
    try:
        Ntotal = ary.shape[axis]
    except AttributeError:
        Ntotal = len(ary)
    try:
        # handle array case.
        Nsections = len(indices_or_sections) + 1
        div_points = [0] + list(indices_or_sections) + [Ntotal]
    except TypeError:
        # indices_or_sections is a scalar, not an array.
        Nsections = int(indices_or_sections)
        if Nsections <= 0:
            raise ValueError('number sections must be larger than 0.')
        Neach_section, extras = divmod(Ntotal, Nsections)
        section_sizes = ([0] +
                         extras * [Neach_section+1] +
                         (Nsections-extras) * [Neach_section])
        div_points = _nx.array(section_sizes, dtype=_nx.intp).cumsum()

    sub_arys = []
    sary = _nx.swapaxes(ary, axis, 0)
    for i in range(Nsections):
        st = div_points[i]
        end = div_points[i + 1]
        sub_arys.append(_nx.swapaxes(sary[st:end], axis, 0))

    return sub_arys 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def dstack(tup):
    """
    Stack arrays in sequence depth wise (along third axis).

    This is equivalent to concatenation along the third axis after 2-D arrays
    of shape `(M,N)` have been reshaped to `(M,N,1)` and 1-D arrays of shape
    `(N,)` have been reshaped to `(1,N,1)`. Rebuilds arrays divided by
    `dsplit`.

    This function makes most sense for arrays with up to 3 dimensions. For
    instance, for pixel-data with a height (first axis), width (second axis),
    and r/g/b channels (third axis). The functions `concatenate`, `stack` and
    `block` provide more general stacking and concatenation operations.

    Parameters
    ----------
    tup : sequence of arrays
        The arrays must have the same shape along all but the third axis.
        1-D or 2-D arrays must have the same shape.

    Returns
    -------
    stacked : ndarray
        The array formed by stacking the given arrays, will be at least 3-D.

    See Also
    --------
    stack : Join a sequence of arrays along a new axis.
    vstack : Stack along first axis.
    hstack : Stack along second axis.
    concatenate : Join a sequence of arrays along an existing axis.
    dsplit : Split array along third axis.

    Examples
    --------
    >>> a = np.array((1,2,3))
    >>> b = np.array((2,3,4))
    >>> np.dstack((a,b))
    array([[[1, 2],
            [2, 3],
            [3, 4]]])

    >>> a = np.array([[1],[2],[3]])
    >>> b = np.array([[2],[3],[4]])
    >>> np.dstack((a,b))
    array([[[1, 2]],
           [[2, 3]],
           [[3, 4]]])

    """
    return _nx.concatenate([atleast_3d(_m) for _m in tup], 2) 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def array_split(ary, indices_or_sections, axis=0):
    """
    Split an array into multiple sub-arrays.

    Please refer to the ``split`` documentation.  The only difference
    between these functions is that ``array_split`` allows
    `indices_or_sections` to be an integer that does *not* equally
    divide the axis. For an array of length l that should be split
    into n sections, it returns l % n sub-arrays of size l//n + 1
    and the rest of size l//n.

    See Also
    --------
    split : Split array into multiple sub-arrays of equal size.

    Examples
    --------
    >>> x = np.arange(8.0)
    >>> np.array_split(x, 3)
        [array([ 0.,  1.,  2.]), array([ 3.,  4.,  5.]), array([ 6.,  7.])]

    >>> x = np.arange(7.0)
    >>> np.array_split(x, 3)
        [array([ 0.,  1.,  2.]), array([ 3.,  4.]), array([ 5.,  6.])]

    """
    try:
        Ntotal = ary.shape[axis]
    except AttributeError:
        Ntotal = len(ary)
    try:
        # handle scalar case.
        Nsections = len(indices_or_sections) + 1
        div_points = [0] + list(indices_or_sections) + [Ntotal]
    except TypeError:
        # indices_or_sections is a scalar, not an array.
        Nsections = int(indices_or_sections)
        if Nsections <= 0:
            raise ValueError('number sections must be larger than 0.')
        Neach_section, extras = divmod(Ntotal, Nsections)
        section_sizes = ([0] +
                         extras * [Neach_section+1] +
                         (Nsections-extras) * [Neach_section])
        div_points = _nx.array(section_sizes).cumsum()

    sub_arys = []
    sary = _nx.swapaxes(ary, axis, 0)
    for i in range(Nsections):
        st = div_points[i]
        end = div_points[i + 1]
        sub_arys.append(_nx.swapaxes(sary[st:end], axis, 0))

    return sub_arys 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def expand_dims(a, axis):
    """
    Expand the shape of an array.

    Insert a new axis, corresponding to a given position in the array shape.

    Parameters
    ----------
    a : array_like
        Input array.
    axis : int
        Position (amongst axes) where new axis is to be inserted.

    Returns
    -------
    res : ndarray
        Output array. The number of dimensions is one greater than that of
        the input array.

    See Also
    --------
    doc.indexing, atleast_1d, atleast_2d, atleast_3d

    Examples
    --------
    >>> x = np.array([1,2])
    >>> x.shape
    (2,)

    The following is equivalent to ``x[np.newaxis,:]`` or ``x[np.newaxis]``:

    >>> y = np.expand_dims(x, axis=0)
    >>> y
    array([[1, 2]])
    >>> y.shape
    (1, 2)

    >>> y = np.expand_dims(x, axis=1)  # Equivalent to x[:,newaxis]
    >>> y
    array([[1],
           [2]])
    >>> y.shape
    (2, 1)

    Note that some examples may use ``None`` instead of ``np.newaxis``.  These
    are the same objects:

    >>> np.newaxis is None
    True

    """
    a = asarray(a)
    shape = a.shape
    if axis < 0:
        axis = axis + len(shape) + 1
    return a.reshape(shape[:axis] + (1,) + shape[axis:]) 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def dstack(tup):
    """
    Stack arrays in sequence depth wise (along third axis).

    Takes a sequence of arrays and stack them along the third axis
    to make a single array. Rebuilds arrays divided by `dsplit`.
    This is a simple way to stack 2D arrays (images) into a single
    3D array for processing.

    This function continues to be supported for backward compatibility, but
    you should prefer ``np.concatenate`` or ``np.stack``. The ``np.stack``
    function was added in NumPy 1.10.

    Parameters
    ----------
    tup : sequence of arrays
        Arrays to stack. All of them must have the same shape along all
        but the third axis.

    Returns
    -------
    stacked : ndarray
        The array formed by stacking the given arrays.

    See Also
    --------
    stack : Join a sequence of arrays along a new axis.
    vstack : Stack along first axis.
    hstack : Stack along second axis.
    concatenate : Join a sequence of arrays along an existing axis.
    dsplit : Split array along third axis.

    Notes
    -----
    Equivalent to ``np.concatenate(tup, axis=2)``.

    Examples
    --------
    >>> a = np.array((1,2,3))
    >>> b = np.array((2,3,4))
    >>> np.dstack((a,b))
    array([[[1, 2],
            [2, 3],
            [3, 4]]])

    >>> a = np.array([[1],[2],[3]])
    >>> b = np.array([[2],[3],[4]])
    >>> np.dstack((a,b))
    array([[[1, 2]],
           [[2, 3]],
           [[3, 4]]])

    """
    return _nx.concatenate([atleast_3d(_m) for _m in tup], 2) 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def array_split(ary, indices_or_sections, axis=0):
    """
    Split an array into multiple sub-arrays.

    Please refer to the ``split`` documentation.  The only difference
    between these functions is that ``array_split`` allows
    `indices_or_sections` to be an integer that does *not* equally
    divide the axis.

    See Also
    --------
    split : Split array into multiple sub-arrays of equal size.

    Examples
    --------
    >>> x = np.arange(8.0)
    >>> np.array_split(x, 3)
        [array([ 0.,  1.,  2.]), array([ 3.,  4.,  5.]), array([ 6.,  7.])]

    """
    try:
        Ntotal = ary.shape[axis]
    except AttributeError:
        Ntotal = len(ary)
    try:
        # handle scalar case.
        Nsections = len(indices_or_sections) + 1
        div_points = [0] + list(indices_or_sections) + [Ntotal]
    except TypeError:
        # indices_or_sections is a scalar, not an array.
        Nsections = int(indices_or_sections)
        if Nsections <= 0:
            raise ValueError('number sections must be larger than 0.')
        Neach_section, extras = divmod(Ntotal, Nsections)
        section_sizes = ([0] +
                         extras * [Neach_section+1] +
                         (Nsections-extras) * [Neach_section])
        div_points = _nx.array(section_sizes).cumsum()

    sub_arys = []
    sary = _nx.swapaxes(ary, axis, 0)
    for i in range(Nsections):
        st = div_points[i]
        end = div_points[i + 1]
        sub_arys.append(_nx.swapaxes(sary[st:end], axis, 0))

    return sub_arys 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def hsplit(ary, indices_or_sections):
    """
    Split an array into multiple sub-arrays horizontally (column-wise).

    Please refer to the `split` documentation.  `hsplit` is equivalent
    to `split` with ``axis=1``, the array is always split along the second
    axis regardless of the array dimension.

    See Also
    --------
    split : Split an array into multiple sub-arrays of equal size.

    Examples
    --------
    >>> x = np.arange(16.0).reshape(4, 4)
    >>> x
    array([[  0.,   1.,   2.,   3.],
           [  4.,   5.,   6.,   7.],
           [  8.,   9.,  10.,  11.],
           [ 12.,  13.,  14.,  15.]])
    >>> np.hsplit(x, 2)
    [array([[  0.,   1.],
           [  4.,   5.],
           [  8.,   9.],
           [ 12.,  13.]]),
     array([[  2.,   3.],
           [  6.,   7.],
           [ 10.,  11.],
           [ 14.,  15.]])]
    >>> np.hsplit(x, np.array([3, 6]))
    [array([[  0.,   1.,   2.],
           [  4.,   5.,   6.],
           [  8.,   9.,  10.],
           [ 12.,  13.,  14.]]),
     array([[  3.],
           [  7.],
           [ 11.],
           [ 15.]]),
     array([], dtype=float64)]

    With a higher dimensional array the split is still along the second axis.

    >>> x = np.arange(8.0).reshape(2, 2, 2)
    >>> x
    array([[[ 0.,  1.],
            [ 2.,  3.]],
           [[ 4.,  5.],
            [ 6.,  7.]]])
    >>> np.hsplit(x, 2)
    [array([[[ 0.,  1.]],
           [[ 4.,  5.]]]),
     array([[[ 2.,  3.]],
           [[ 6.,  7.]]])]

    """
    if len(_nx.shape(ary)) == 0:
        raise ValueError('hsplit only works on arrays of 1 or more dimensions')
    if len(ary.shape) > 1:
        return split(ary, indices_or_sections, 1)
    else:
        return split(ary, indices_or_sections, 0) 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def vsplit(ary, indices_or_sections):
    """
    Split an array into multiple sub-arrays vertically (row-wise).

    Please refer to the ``split`` documentation.  ``vsplit`` is equivalent
    to ``split`` with `axis=0` (default), the array is always split along the
    first axis regardless of the array dimension.

    See Also
    --------
    split : Split an array into multiple sub-arrays of equal size.

    Examples
    --------
    >>> x = np.arange(16.0).reshape(4, 4)
    >>> x
    array([[  0.,   1.,   2.,   3.],
           [  4.,   5.,   6.,   7.],
           [  8.,   9.,  10.,  11.],
           [ 12.,  13.,  14.,  15.]])
    >>> np.vsplit(x, 2)
    [array([[ 0.,  1.,  2.,  3.],
           [ 4.,  5.,  6.,  7.]]),
     array([[  8.,   9.,  10.,  11.],
           [ 12.,  13.,  14.,  15.]])]
    >>> np.vsplit(x, np.array([3, 6]))
    [array([[  0.,   1.,   2.,   3.],
           [  4.,   5.,   6.,   7.],
           [  8.,   9.,  10.,  11.]]),
     array([[ 12.,  13.,  14.,  15.]]),
     array([], dtype=float64)]

    With a higher dimensional array the split is still along the first axis.

    >>> x = np.arange(8.0).reshape(2, 2, 2)
    >>> x
    array([[[ 0.,  1.],
            [ 2.,  3.]],
           [[ 4.,  5.],
            [ 6.,  7.]]])
    >>> np.vsplit(x, 2)
    [array([[[ 0.,  1.],
            [ 2.,  3.]]]),
     array([[[ 4.,  5.],
            [ 6.,  7.]]])]

    """
    if len(_nx.shape(ary)) < 2:
        raise ValueError('vsplit only works on arrays of 2 or more dimensions')
    return split(ary, indices_or_sections, 0) 

# 需要导入模块: from numpy.core import numeric [as 别名]
# 或者: from numpy.core.numeric import shape [as 别名]
def dsplit(ary, indices_or_sections):
    """
    Split array into multiple sub-arrays along the 3rd axis (depth).

    Please refer to the `split` documentation.  `dsplit` is equivalent
    to `split` with ``axis=2``, the array is always split along the third
    axis provided the array dimension is greater than or equal to 3.

    See Also
    --------
    split : Split an array into multiple sub-arrays of equal size.

    Examples
    --------
    >>> x = np.arange(16.0).reshape(2, 2, 4)
    >>> x
    array([[[  0.,   1.,   2.,   3.],
            [  4.,   5.,   6.,   7.]],
           [[  8.,   9.,  10.,  11.],
            [ 12.,  13.,  14.,  15.]]])
    >>> np.dsplit(x, 2)
    [array([[[  0.,   1.],
            [  4.,   5.]],
           [[  8.,   9.],
            [ 12.,  13.]]]),
     array([[[  2.,   3.],
            [  6.,   7.]],
           [[ 10.,  11.],
            [ 14.,  15.]]])]
    >>> np.dsplit(x, np.array([3, 6]))
    [array([[[  0.,   1.,   2.],
            [  4.,   5.,   6.]],
           [[  8.,   9.,  10.],
            [ 12.,  13.,  14.]]]),
     array([[[  3.],
            [  7.]],
           [[ 11.],
            [ 15.]]]),
     array([], dtype=float64)]

    """
    if len(_nx.shape(ary)) < 3:
        raise ValueError('dsplit only works on arrays of 3 or more dimensions')
    return split(ary, indices_or_sections, 2)