Exemplo n.º 1
0
def check_int_a2f(in_type, out_type):
    # Check that array to / from file returns roughly the same as input
    big_floater = np.maximum_sctype(np.float)
    info = type_info(in_type)
    this_min, this_max = info['min'], info['max']
    if not in_type in np.sctypes['complex']:
        data = np.array([this_min, this_max], in_type)
    else:  # Funny behavior with complex256
        data = np.zeros((2, ), in_type)
        data[0] = this_min + 0j
        data[1] = this_max + 0j
    str_io = BytesIO()
    try:
        scale, inter, mn, mx = calculate_scale(data, out_type, True)
    except ValueError:
        if DEBUG:
            print in_type, out_type, sys.exc_info()[1]
        return
    array_to_file(data, str_io, out_type, 0, inter, scale, mn, mx)
    data_back = array_from_file(data.shape, out_type, str_io)
    data_back = apply_read_scaling(data_back, scale, inter)
    assert_true(np.allclose(big_floater(data), big_floater(data_back)))
    # Try with analyze-size scale and inter
    scale32 = np.float32(scale)
    inter32 = np.float32(inter)
    if scale32 == np.inf or inter32 == np.inf:
        return
    data_back = array_from_file(data.shape, out_type, str_io)
    data_back = apply_read_scaling(data_back, scale32, inter32)
    # Clip at extremes to remove inf
    info = type_info(in_type)
    out_min, out_max = info['min'], info['max']
    assert_true(
        np.allclose(big_floater(data),
                    big_floater(np.clip(data_back, out_min, out_max))))
Exemplo n.º 2
0
def check_int_a2f(in_type, out_type):
    # Check that array to / from file returns roughly the same as input
    big_floater = np.maximum_sctype(np.float)
    info = type_info(in_type)
    this_min, this_max = info['min'], info['max']
    if not in_type in np.sctypes['complex']:
        data = np.array([this_min, this_max], in_type)
    else: # Funny behavior with complex256
        data = np.zeros((2,), in_type)
        data[0] = this_min + 0j
        data[1] = this_max + 0j
    str_io = BytesIO()
    try:
        scale, inter, mn, mx = calculate_scale(data, out_type, True)
    except ValueError:
        if DEBUG:
            print in_type, out_type, sys.exc_info()[1]
        return
    array_to_file(data, str_io, out_type, 0, inter, scale, mn, mx)
    data_back = array_from_file(data.shape, out_type, str_io)
    data_back = apply_read_scaling(data_back, scale, inter)
    assert_true(np.allclose(big_floater(data), big_floater(data_back)))
    # Try with analyze-size scale and inter
    scale32 = np.float32(scale)
    inter32 = np.float32(inter)
    if scale32 == np.inf or inter32 == np.inf:
        return
    data_back = array_from_file(data.shape, out_type, str_io)
    data_back = apply_read_scaling(data_back, scale32, inter32)
    # Clip at extremes to remove inf
    info = type_info(in_type)
    out_min, out_max = info['min'], info['max']
    assert_true(np.allclose(big_floater(data),
                            big_floater(np.clip(data_back, out_min, out_max))))
Exemplo n.º 3
0
def test_scale_min_max():
    mx_dt = np.maximum_sctype(np.float)
    for tp in np.sctypes['uint'] + np.sctypes['int']:
        info = np.iinfo(tp)
        # Need to pump up to max fp type to contain python longs
        imin = np.array(info.min, dtype=mx_dt)
        imax = np.array(info.max, dtype=mx_dt)
        value_pairs = (
            (0, imax),
            (imin, 0),
            (imin, imax),
            (1, 10),
            (-1, -1),
            (1, 1),
            (-10, -1),
            (-100, 10))
        for mn, mx in value_pairs:
            # with intercept
            scale, inter = scale_min_max(mn, mx, tp, True)
            if mx-mn:
                assert_array_almost_equal, (mx-inter) / scale, imax
                assert_array_almost_equal, (mn-inter) / scale, imin
            else:
                assert_equal, (scale, inter), (1.0, mn)
            # without intercept
            if imin == 0 and mn < 0 and mx > 0:
                (assert_raises, ValueError,
                       scale_min_max, mn, mx, tp, False)
                continue
            scale, inter = scale_min_max(mn, mx, tp, False)
            assert_equal, inter, 0.0
            if mn == 0 and mx == 0:
                assert_equal, scale, 1.0
                continue
            sc_mn = mn / scale
            sc_mx = mx / scale
            assert_true, sc_mn >= imin
            assert_true, sc_mx <= imax
            if imin == 0:
                if mx > 0: # numbers all +ve
                    assert_array_almost_equal, mx / scale, imax
                else: # numbers all -ve
                    assert_array_almost_equal, mn / scale, imax
                continue
            if abs(mx) >= abs(mn):
                assert_array_almost_equal, mx / scale, imax
            else:
                assert_array_almost_equal, mn / scale, imin
Exemplo n.º 4
0
def test_scale_min_max():
    mx_dt = np.maximum_sctype(np.float)
    for tp in np.sctypes['uint'] + np.sctypes['int']:
        info = np.iinfo(tp)
        # Need to pump up to max fp type to contain python longs
        imin = np.array(info.min, dtype=mx_dt)
        imax = np.array(info.max, dtype=mx_dt)
        value_pairs = (
            (0, imax),
            (imin, 0),
            (imin, imax),
            (1, 10),
            (-1, -1),
            (1, 1),
            (-10, -1),
            (-100, 10))
        for mn, mx in value_pairs:
            # with intercept
            scale, inter = scale_min_max(mn, mx, tp, True)
            if mx - mn:
                assert_array_almost_equal, (mx - inter) / scale, imax
                assert_array_almost_equal, (mn - inter) / scale, imin
            else:
                assert_equal, (scale, inter), (1.0, mn)
            # without intercept
            if imin == 0 and mn < 0 and mx > 0:
                (assert_raises, ValueError,
                 scale_min_max, mn, mx, tp, False)
                continue
            scale, inter = scale_min_max(mn, mx, tp, False)
            assert_equal, inter, 0.0
            if mn == 0 and mx == 0:
                assert_equal, scale, 1.0
                continue
            sc_mn = mn / scale
            sc_mx = mx / scale
            assert_true, sc_mn >= imin
            assert_true, sc_mx <= imax
            if imin == 0:
                if mx > 0:  # numbers all +ve
                    assert_array_almost_equal, mx / scale, imax
                else:  # numbers all -ve
                    assert_array_almost_equal, mn / scale, imax
                continue
            if abs(mx) >= abs(mn):
                assert_array_almost_equal, mx / scale, imax
            else:
                assert_array_almost_equal, mn / scale, imin
Exemplo n.º 5
0
def check_int_a2f(in_type, out_type):
    # Check that array to / from file returns roughly the same as input
    big_floater = np.maximum_sctype(np.float)
    info = type_info(in_type)
    this_min, this_max = info['min'], info['max']
    if not in_type in np.sctypes['complex']:
        data = np.array([this_min, this_max], in_type)
        # Bug in numpy 1.6.2 on PPC leading to infs - abort
        if not np.all(np.isfinite(data)):
            if DEBUG:
                print(f'Hit PPC max -> inf bug; skip in_type {in_type}')
            return
    else:  # Funny behavior with complex256
        data = np.zeros((2, ), in_type)
        data[0] = this_min + 0j
        data[1] = this_max + 0j
    str_io = BytesIO()
    try:
        scale, inter, mn, mx = _calculate_scale(data, out_type, True)
    except ValueError as e:
        if DEBUG:
            warnings.warn(str((in_type, out_type, e)))
        return
    array_to_file(data, str_io, out_type, 0, inter, scale, mn, mx)
    data_back = array_from_file(data.shape, out_type, str_io)
    data_back = apply_read_scaling(data_back, scale, inter)
    assert np.allclose(big_floater(data), big_floater(data_back))
    # Try with analyze-size scale and inter
    scale32 = np.float32(scale)
    inter32 = np.float32(inter)
    if scale32 == np.inf or inter32 == np.inf:
        return
    data_back = array_from_file(data.shape, out_type, str_io)
    data_back = apply_read_scaling(data_back, scale32, inter32)
    # Clip at extremes to remove inf
    info = type_info(in_type)
    out_min, out_max = info['min'], info['max']
    assert np.allclose(big_floater(data),
                       big_floater(np.clip(data_back, out_min, out_max)))
Exemplo n.º 6
0
real (scalar) part, and ``x, y, z`` are the complex (vector) part.

Note - rotation matrices here apply to column vectors, that is,
they are applied on the left of the vector.  For example:

>>> import numpy as np
>>> q = [0, 1, 0, 0] # 180 degree rotation around axis 0
>>> M = quat2mat(q) # from this module
>>> vec = np.array([1, 2, 3]).reshape((3,1)) # column vector
>>> tvec = np.dot(M, vec)
'''

import math
import numpy as np

MAX_FLOAT = np.maximum_sctype(np.float)
FLOAT_EPS = np.finfo(np.float).eps


def fillpositive(xyz, w2_thresh=None):
    ''' Compute unit quaternion from last 3 values

    Parameters
    ----------
    xyz : iterable
       iterable containing 3 values, corresponding to quaternion x, y, z
    w2_thresh : None or float, optional
       threshold to determine if w squared is really negative.
       If None (default) then w2_thresh set equal to
       ``-np.finfo(xyz.dtype).eps``, if possible, otherwise
       ``-np.finfo(np.float).eps``
Exemplo n.º 7
0
 def test_other(self, t):
     assert_equal(np.maximum_sctype(t), t)
Exemplo n.º 8
0
 def test_complex(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes['complex'][-1])
Exemplo n.º 9
0
 def test_float(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes['float'][-1])
Exemplo n.º 10
0
#          and string comma- (or '+') separated lists of bit flags).
#       5. Added 'is_bit_flag()' function to check if an integer number has
#          only one bit set (i.e., that it is a power of 2).
# 1.1.0 (29-January-2018) - Multiple enhancements:
#       1. Added support for long type in Python 2.7 in
#          `interpret_bit_flags()` and `bitfield_to_boolean_mask()`.
#       2. `interpret_bit_flags()` now always returns `int` (or `int` or `long`
#           in Python 2.7). Previously when input was of integer-like type
#           (i.e., `numpy.uint64`), it was not converted to Python `int`.
#       3. `bitfield_to_boolean_mask()` will no longer crash when
#          `ignore_flags` argument contains bit flags beyond what the type of
#          the argument `bitfield` can hold.
# 1.1.1 (30-January-2018) - Improved filtering of high bits in flags.
#
INT_TYPE = (int, long,) if sys.version_info < (3,) else (int,)
MAX_UINT_TYPE = np.maximum_sctype(np.uint)
SUPPORTED_FLAGS = int(np.bitwise_not(
    0, dtype=MAX_UINT_TYPE, casting='unsafe'
))


def is_bit_flag(n):
    """
    Verifies if the input number is a bit flag (i.e., an integer number that is
    an integer power of 2).

    Parameters
    ----------
    n : int
        A positive integer number. Non-positive integers are considered not to
        be "flags".
Exemplo n.º 11
0
 def test_float(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes['float'][-1])
Exemplo n.º 12
0
 def test_other(self, t):
     assert_equal(np.maximum_sctype(t), t)
Exemplo n.º 13
0
 def test_int(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes["int"][-1])
Exemplo n.º 14
0
def scale_min_max(mn, mx, out_type, allow_intercept):
    ''' Return scaling and intercept min, max of data, given output type

    Returns ``scalefactor`` and ``intercept`` to best fit data with
    given ``mn`` and ``mx`` min and max values into range of data type
    with ``type_min`` and ``type_max`` min and max values for type.

    The calculated scaling is therefore::

        scaled_data = (data-intercept) / scalefactor

    Parameters
    ----------
    mn : scalar
       data minimum value
    mx : scalar
       data maximum value
    out_type : numpy type
       numpy type of output
    allow_intercept : bool
       If true, allow calculation of non-zero intercept.  Otherwise,
       returned intercept is always 0.0

    Returns
    -------
    scalefactor : numpy scalar, dtype=np.maximum_sctype(np.float)
       scalefactor by which to divide data after subtracting intercept
    intercept : numpy scalar, dtype=np.maximum_sctype(np.float)
       value to subtract from data before dividing by scalefactor

    Examples
    --------
    >>> scale_min_max(0, 255, np.uint8, False)
    (1.0, 0.0)
    >>> scale_min_max(-128, 127, np.int8, False)
    (1.0, 0.0)
    >>> scale_min_max(0, 127, np.int8, False)
    (1.0, 0.0)
    >>> scaling, intercept = scale_min_max(0, 127, np.int8,  True)
    >>> np.allclose((0 - intercept) / scaling, -128)
    True
    >>> np.allclose((127 - intercept) / scaling, 127)
    True
    >>> scaling, intercept = scale_min_max(-10, -1, np.int8, True)
    >>> np.allclose((-10 - intercept) / scaling, -128)
    True
    >>> np.allclose((-1 - intercept) / scaling, 127)
    True
    >>> scaling, intercept = scale_min_max(1, 10, np.int8, True)
    >>> np.allclose((1 - intercept) / scaling, -128)
    True
    >>> np.allclose((10 - intercept) / scaling, 127)
    True

    Notes
    -----
    We don't use this function anywhere in nibabel now, it's here for API
    compatibility only.

    The large integers lead to python long types as max / min for type.
    To contain the rounding error, we need to use the maximum numpy
    float types when casting to float.
    '''
    if mn > mx:
        raise ValueError('min value > max value')
    info = type_info(out_type)
    mn, mx, type_min, type_max = np.array(
        [mn, mx, info['min'], info['max']], np.maximum_sctype(np.float))
    # with intercept
    if allow_intercept:
        data_range = mx-mn
        if data_range == 0:
            return 1.0, mn
        type_range = type_max - type_min
        scaling = data_range / type_range
        intercept = mn - type_min * scaling
        return scaling, intercept
    # without intercept
    if mx == 0 and mn == 0:
        return 1.0, 0.0
    if type_min == 0: # uint
        if mn < 0 and mx > 0:
            raise ValueError('Cannot scale negative and positive '
                             'numbers to uint without intercept')
        if mx < 0:
            scaling = mn / type_max
        else:
            scaling = mx / type_max
    else: # int
        if abs(mx) >= abs(mn):
            scaling = mx / type_max
        else:
            scaling = mn / type_min
    return scaling, 0.0
Exemplo n.º 15
0
def scale_min_max(mn, mx, out_type, allow_intercept):
    ''' Return scaling and intercept min, max of data, given output type

    Returns ``scalefactor`` and ``intercept`` to best fit data with
    given ``mn`` and ``mx`` min and max values into range of data type
    with ``type_min`` and ``type_max`` min and max values for type.

    The calculated scaling is therefore::

        scaled_data = (data-intercept) / scalefactor

    Parameters
    ----------
    mn : scalar
       data minimum value
    mx : scalar
       data maximum value
    out_type : numpy type
       numpy type of output
    allow_intercept : bool
       If true, allow calculation of non-zero intercept.  Otherwise,
       returned intercept is always 0.0

    Returns
    -------
    scalefactor : numpy scalar, dtype=np.maximum_sctype(np.float)
       scalefactor by which to divide data after subtracting intercept
    intercept : numpy scalar, dtype=np.maximum_sctype(np.float)
       value to subtract from data before dividing by scalefactor

    Examples
    --------
    >>> scale_min_max(0, 255, np.uint8, False)
    (1.0, 0.0)
    >>> scale_min_max(-128, 127, np.int8, False)
    (1.0, 0.0)
    >>> scale_min_max(0, 127, np.int8, False)
    (1.0, 0.0)
    >>> scaling, intercept = scale_min_max(0, 127, np.int8,  True)
    >>> np.allclose((0 - intercept) / scaling, -128)
    True
    >>> np.allclose((127 - intercept) / scaling, 127)
    True
    >>> scaling, intercept = scale_min_max(-10, -1, np.int8, True)
    >>> np.allclose((-10 - intercept) / scaling, -128)
    True
    >>> np.allclose((-1 - intercept) / scaling, 127)
    True
    >>> scaling, intercept = scale_min_max(1, 10, np.int8, True)
    >>> np.allclose((1 - intercept) / scaling, -128)
    True
    >>> np.allclose((10 - intercept) / scaling, 127)
    True

    Notes
    -----
    We don't use this function anywhere in nibabel now, it's here for API
    compatibility only.

    The large integers lead to python long types as max / min for type.
    To contain the rounding error, we need to use the maximum numpy
    float types when casting to float.
    '''
    if mn > mx:
        raise ValueError('min value > max value')
    info = type_info(out_type)
    mn, mx, type_min, type_max = np.array([mn, mx, info['min'], info['max']],
                                          np.maximum_sctype(np.float))
    # with intercept
    if allow_intercept:
        data_range = mx - mn
        if data_range == 0:
            return 1.0, mn
        type_range = type_max - type_min
        scaling = data_range / type_range
        intercept = mn - type_min * scaling
        return scaling, intercept
    # without intercept
    if mx == 0 and mn == 0:
        return 1.0, 0.0
    if type_min == 0:  # uint
        if mn < 0 and mx > 0:
            raise ValueError('Cannot scale negative and positive '
                             'numbers to uint without intercept')
        if mx < 0:
            scaling = mn / type_max
        else:
            scaling = mx / type_max
    else:  # int
        if abs(mx) >= abs(mn):
            scaling = mx / type_max
        else:
            scaling = mn / type_min
    return scaling, 0.0
Exemplo n.º 16
0
import numpy as np

# Techincally this works, but probably shouldn't. See
#
# https://github.com/numpy/numpy/issues/16366
#
np.maximum_sctype(1)  # E: incompatible type "int"

np.issubsctype(1, np.int64)  # E: incompatible type "int"

np.issubdtype(1, np.int64)  # E: incompatible type "int"

np.find_common_type(
    np.int64, np.int64)  # E: incompatible type "Type[signedinteger[Any]]"
Exemplo n.º 17
0
import numpy as np


#todo 实现两个矩阵相加
def native_add(x, y):
    assert len(x.shape) == 2  #todo 判断x是否为2D张量
    assert x.shape == y.shape  #todo 判断两个矩阵是否相等

    x = x.copy()
    for i in range(x.shape[0]):
        for j in range(x.shape[1]):
            x[i, j] += y[i, j]
    return x


num1 = np.array([[1, 2, 3, 4], [3, 4, 5, 6], [5, 6, 7, 8]])

num2 = np.array([[2, 3, 4, 5], [3, 4, 5, 6], [4, 5, 6, 7]])

num3 = np.array([[2, 3, 4, 5], [3, 4, 5, 6]])

z = num1 + num2
z = np.maximum_sctype()(z, 0)
print(z)
#print(native_add((num1, num3))) #todo 根据矩阵相加的法则,那么当两个矩阵大小不同时,那么会出现错误
print(native_add(num1, num2))
Exemplo n.º 18
0
"""
A module containing unit tests for the `bitmask` modue.

Licensed under a 3-clause BSD style license - see LICENSE.rst

"""
import warnings
import numpy as np
import pytest

from astropy.nddata import bitmask

MAX_INT_TYPE = np.maximum_sctype(np.int_)
MAX_UINT_TYPE = np.maximum_sctype(np.uint)
MAX_UINT_FLAG = np.left_shift(MAX_UINT_TYPE(1),
                              MAX_UINT_TYPE(np.iinfo(MAX_UINT_TYPE).bits - 1))
MAX_INT_FLAG = np.left_shift(MAX_INT_TYPE(1),
                             MAX_INT_TYPE(np.iinfo(MAX_INT_TYPE).bits - 2))
SUPER_LARGE_FLAG = 1 << np.iinfo(MAX_UINT_TYPE).bits
EXTREME_TEST_DATA = np.array([
    0, 1, 1 + 1 << 2, MAX_INT_FLAG, ~0,
    MAX_INT_TYPE(MAX_UINT_FLAG), 1 + MAX_INT_TYPE(MAX_UINT_FLAG)
],
                             dtype=MAX_INT_TYPE)


@pytest.mark.parametrize('flag', [0, -1])
def test_nonpositive_not_a_bit_flag(flag):
    assert not bitmask._is_bit_flag(n=flag)

Exemplo n.º 19
0
import numpy as np

reveal_type(np.maximum_sctype(np.float64))  # E: Type[{float64}]
reveal_type(np.maximum_sctype("f8"))  # E: Type[Any]

reveal_type(np.issctype(np.float64))  # E: bool
reveal_type(np.issctype("foo"))  # E: Literal[False]

reveal_type(np.obj2sctype(np.float64))  # E: Union[None, Type[{float64}]]
reveal_type(np.obj2sctype(
    np.float64, default=False))  # E: Union[builtins.bool, Type[{float64}]]
reveal_type(np.obj2sctype("S8"))  # E: Union[None, Type[Any]]
reveal_type(np.obj2sctype("S8", default=None))  # E: Union[None, Type[Any]]
reveal_type(np.obj2sctype("foo",
                          default=False))  # E: Union[builtins.bool, Type[Any]]
reveal_type(np.obj2sctype(1))  # E: None
reveal_type(np.obj2sctype(1, default=False))  # E: bool

reveal_type(np.issubclass_(np.float64, float))  # E: bool
reveal_type(np.issubclass_(np.float64, (int, float)))  # E: bool
reveal_type(np.issubclass_(1, 1))  # E: Literal[False]

reveal_type(np.sctype2char("S8"))  # E: str
reveal_type(np.sctype2char(list))  # E: str

reveal_type(np.find_common_type([np.int64], [np.int64]))  # E: numpy.dtype[Any]

reveal_type(np.cast[int])  # E: _CastFunc
reveal_type(np.cast["i8"])  # E: _CastFunc
reveal_type(np.cast[np.int64])  # E: _CastFunc
Exemplo n.º 20
0
 def test_uint(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes['uint'][-1])
Exemplo n.º 21
0
 def test_uint(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes['uint'][-1])
Exemplo n.º 22
0
 def test_complex(self, t):
     assert_equal(np.maximum_sctype(t), np.sctypes['complex'][-1])
Exemplo n.º 23
0
import numpy as np

np.maximum_sctype("S8")
np.maximum_sctype(object)

np.issctype(object)
np.issctype("S8")

np.obj2sctype(list)
np.obj2sctype(list, default=None)
np.obj2sctype(list, default=np.string_)

np.issubclass_(np.int32, int)
np.issubclass_(np.float64, float)
np.issubclass_(np.float64, (int, float))

np.issubsctype("int64", int)
np.issubsctype(np.array([1]), np.array([1]))

np.issubdtype("S1", np.string_)
np.issubdtype(np.float64, np.float32)

np.sctype2char("S1")
np.sctype2char(list)

np.find_common_type([], [np.int64, np.float32, complex])
np.find_common_type((), (np.int64, np.float32, complex))
np.find_common_type([np.int64, np.float32], [])
np.find_common_type([np.float32], [np.int64, np.float64])

np.cast[int]
Exemplo n.º 24
0
>>> M = quat2mat(q) # from this module
>>> vec = np.array([1, 2, 3]).reshape((3,1)) # column vector
>>> tvec = np.dot(M, vec)

Terms used in function names:

* *mat* : array shape (3, 3) (3D non-homogenous coordinates)
* *aff* : affine array shape (4, 4) (3D homogenous coordinates)
* *quat* : quaternion shape (4,)
* *axangle* : rotations encoded by axis vector and angle scalar
'''

import math
import numpy as np

_MAX_FLOAT = np.maximum_sctype(np.float)
_FLOAT_EPS = np.finfo(np.float).eps


def fillpositive(xyz, w2_thresh=None):
    ''' Compute unit quaternion from last 3 values

    Parameters
    ----------
    xyz : iterable
       iterable containing 3 values, corresponding to quaternion x, y, z
    w2_thresh : None or float, optional
       threshold to determine if w squared is really negative.
       If None (default) then w2_thresh set equal to
       ``-np.finfo(xyz.dtype).eps``, if possible, otherwise
       ``-np.finfo(np.float).eps``
Exemplo n.º 25
0
import numpy as np

# Technically this works, but probably shouldn't. See
#
# https://github.com/numpy/numpy/issues/16366
#
np.maximum_sctype(1)  # E: No overload variant

np.issubsctype(1, np.int64)  # E: incompatible type

np.issubdtype(1, np.int64)  # E: incompatible type

np.find_common_type(np.int64, np.int64)  # E: incompatible type