from __future__ import division, absolute_import, print_function

import platform
import warnings
import fnmatch
import itertools
import pytest

import numpy.core.umath as ncu
from numpy.core import _umath_tests as ncu_tests
import numpy as np
from numpy.testing import (
    assert_, assert_equal, assert_raises, assert_raises_regex,
    assert_array_equal, assert_almost_equal, assert_array_almost_equal,
    assert_allclose, assert_no_warnings, suppress_warnings,
    _gen_alignment_data
    )


def on_powerpc():
    """ True if we are running on a Power PC platform."""
    return platform.processor() == 'powerpc' or \
           platform.machine().startswith('ppc')


class _FilterInvalids(object):
    def setup(self):
        self.olderr = np.seterr(invalid='ignore')

    def teardown(self):
        np.seterr(**self.olderr)


class TestConstants(object):
    def test_pi(self):
        assert_allclose(ncu.pi, 3.141592653589793, 1e-15)

    def test_e(self):
        assert_allclose(ncu.e, 2.718281828459045, 1e-15)

    def test_euler_gamma(self):
        assert_allclose(ncu.euler_gamma, 0.5772156649015329, 1e-15)


class TestOut(object):
    def test_out_subok(self):
        for subok in (True, False):
            a = np.array(0.5)
            o = np.empty(())

            r = np.add(a, 2, o, subok=subok)
            assert_(r is o)
            r = np.add(a, 2, out=o, subok=subok)
            assert_(r is o)
            r = np.add(a, 2, out=(o,), subok=subok)
            assert_(r is o)

            d = np.array(5.7)
            o1 = np.empty(())
            o2 = np.empty((), dtype=np.int32)

            r1, r2 = np.frexp(d, o1, None, subok=subok)
            assert_(r1 is o1)
            r1, r2 = np.frexp(d, None, o2, subok=subok)
            assert_(r2 is o2)
            r1, r2 = np.frexp(d, o1, o2, subok=subok)
            assert_(r1 is o1)
            assert_(r2 is o2)

            r1, r2 = np.frexp(d, out=(o1, None), subok=subok)
            assert_(r1 is o1)
            r1, r2 = np.frexp(d, out=(None, o2), subok=subok)
            assert_(r2 is o2)
            r1, r2 = np.frexp(d, out=(o1, o2), subok=subok)
            assert_(r1 is o1)
            assert_(r2 is o2)

            with warnings.catch_warnings(record=True) as w:
                warnings.filterwarnings('always', '', DeprecationWarning)
                r1, r2 = np.frexp(d, out=o1, subok=subok)
                assert_(r1 is o1)
                assert_(w[0].category is DeprecationWarning)

            assert_raises(ValueError, np.add, a, 2, o, o, subok=subok)
            assert_raises(ValueError, np.add, a, 2, o, out=o, subok=subok)
            assert_raises(ValueError, np.add, a, 2, None, out=o, subok=subok)
            assert_raises(ValueError, np.add, a, 2, out=(o, o), subok=subok)
            assert_raises(ValueError, np.add, a, 2, out=(), subok=subok)
            assert_raises(TypeError, np.add, a, 2, [], subok=subok)
            assert_raises(TypeError, np.add, a, 2, out=[], subok=subok)
            assert_raises(TypeError, np.add, a, 2, out=([],), subok=subok)
            o.flags.writeable = False
            assert_raises(ValueError, np.add, a, 2, o, subok=subok)
            assert_raises(ValueError, np.add, a, 2, out=o, subok=subok)
            assert_raises(ValueError, np.add, a, 2, out=(o,), subok=subok)

    def test_out_wrap_subok(self):
        class ArrayWrap(np.ndarray):
            __array_priority__ = 10

            def __new__(cls, arr):
                return np.asarray(arr).view(cls).copy()

            def __array_wrap__(self, arr, context):
                return arr.view(type(self))

        for subok in (True, False):
            a = ArrayWrap([0.5])

            r = np.add(a, 2, subok=subok)
            if subok:
                assert_(isinstance(r, ArrayWrap))
            else:
                assert_(type(r) == np.ndarray)

            r = np.add(a, 2, None, subok=subok)
            if subok:
                assert_(isinstance(r, ArrayWrap))
            else:
                assert_(type(r) == np.ndarray)

            r = np.add(a, 2, out=None, subok=subok)
            if subok:
                assert_(isinstance(r, ArrayWrap))
            else:
                assert_(type(r) == np.ndarray)

            r = np.add(a, 2, out=(None,), subok=subok)
            if subok:
                assert_(isinstance(r, ArrayWrap))
            else:
                assert_(type(r) == np.ndarray)

            d = ArrayWrap([5.7])
            o1 = np.empty((1,))
            o2 = np.empty((1,), dtype=np.int32)

            r1, r2 = np.frexp(d, o1, subok=subok)
            if subok:
                assert_(isinstance(r2, ArrayWrap))
            else:
                assert_(type(r2) == np.ndarray)

            r1, r2 = np.frexp(d, o1, None, subok=subok)
            if subok:
                assert_(isinstance(r2, ArrayWrap))
            else:
                assert_(type(r2) == np.ndarray)

            r1, r2 = np.frexp(d, None, o2, subok=subok)
            if subok:
                assert_(isinstance(r1, ArrayWrap))
            else:
                assert_(type(r1) == np.ndarray)

            r1, r2 = np.frexp(d, out=(o1, None), subok=subok)
            if subok:
                assert_(isinstance(r2, ArrayWrap))
            else:
                assert_(type(r2) == np.ndarray)

            r1, r2 = np.frexp(d, out=(None, o2), subok=subok)
            if subok:
                assert_(isinstance(r1, ArrayWrap))
            else:
                assert_(type(r1) == np.ndarray)

            with warnings.catch_warnings(record=True) as w:
                warnings.filterwarnings('always', '', DeprecationWarning)
                r1, r2 = np.frexp(d, out=o1, subok=subok)
                if subok:
                    assert_(isinstance(r2, ArrayWrap))
                else:
                    assert_(type(r2) == np.ndarray)
                assert_(w[0].category is DeprecationWarning)


class TestComparisons(object):
    def test_ignore_object_identity_in_equal(self):
        # Check error raised when comparing identical objects whose comparison
        # is not a simple boolean, e.g., arrays that are compared elementwise.
        a = np.array([np.array([1, 2, 3]), None], dtype=object)
        assert_raises(ValueError, np.equal, a, a)

        # Check error raised when comparing identical non-comparable objects.
        class FunkyType(object):
            def __eq__(self, other):
                raise TypeError("I won't compare")

        a = np.array([FunkyType()])
        assert_raises(TypeError, np.equal, a, a)

        # Check identity doesn't override comparison mismatch.
        a = np.array([np.nan], dtype=object)
        assert_equal(np.equal(a, a), [False])

    def test_ignore_object_identity_in_not_equal(self):
        # Check error raised when comparing identical objects whose comparison
        # is not a simple boolean, e.g., arrays that are compared elementwise.
        a = np.array([np.array([1, 2, 3]), None], dtype=object)
        assert_raises(ValueError, np.not_equal, a, a)

        # Check error raised when comparing identical non-comparable objects.
        class FunkyType(object):
            def __ne__(self, other):
                raise TypeError("I won't compare")

        a = np.array([FunkyType()])
        assert_raises(TypeError, np.not_equal, a, a)

        # Check identity doesn't override comparison mismatch.
        a = np.array([np.nan], dtype=object)
        assert_equal(np.not_equal(a, a), [True])


class TestAdd(object):
    def test_reduce_alignment(self):
        # gh-9876
        # make sure arrays with weird strides work with the optimizations in
        # pairwise_sum_@TYPE@. On x86, the 'b' field will count as aligned at a
        # 4 byte offset, even though its itemsize is 8.
        a = np.zeros(2, dtype=[('a', np.int32), ('b', np.float64)])
        a['a'] = -1
        assert_equal(a['b'].sum(), 0)


class TestDivision(object):
    def test_division_int(self):
        # int division should follow Python
        x = np.array([5, 10, 90, 100, -5, -10, -90, -100, -120])
        if 5 / 10 == 0.5:
            assert_equal(x / 100, [0.05, 0.1, 0.9, 1,
                                   -0.05, -0.1, -0.9, -1, -1.2])
        else:
            assert_equal(x / 100, [0, 0, 0, 1, -1, -1, -1, -1, -2])
        assert_equal(x // 100, [0, 0, 0, 1, -1, -1, -1, -1, -2])
        assert_equal(x % 100, [5, 10, 90, 0, 95, 90, 10, 0, 80])

    def test_division_complex(self):
        # check that implementation is correct
        msg = "Complex division implementation check"
        x = np.array([1. + 1.*1j, 1. + .5*1j, 1. + 2.*1j], dtype=np.complex128)
        assert_almost_equal(x**2/x, x, err_msg=msg)
        # check overflow, underflow
        msg = "Complex division overflow/underflow check"
        x = np.array([1.e+110, 1.e-110], dtype=np.complex128)
        y = x**2/x
        assert_almost_equal(y/x, [1, 1], err_msg=msg)

    def test_zero_division_complex(self):
        with np.errstate(invalid="ignore", divide="ignore"):
            x = np.array([0.0], dtype=np.complex128)
            y = 1.0/x
            assert_(np.isinf(y)[0])
            y = complex(np.inf, np.nan)/x
            assert_(np.isinf(y)[0])
            y = complex(np.nan, np.inf)/x
            assert_(np.isinf(y)[0])
            y = complex(np.inf, np.inf)/x
            assert_(np.isinf(y)[0])
            y = 0.0/x
            assert_(np.isnan(y)[0])

    def test_floor_division_complex(self):
        # check that implementation is correct
        msg = "Complex floor division implementation check"
        x = np.array([.9 + 1j, -.1 + 1j, .9 + .5*1j, .9 + 2.*1j], dtype=np.complex128)
        y = np.array([0., -1., 0., 0.], dtype=np.complex128)
        assert_equal(np.floor_divide(x**2, x), y, err_msg=msg)
        # check overflow, underflow
        msg = "Complex floor division overflow/underflow check"
        x = np.array([1.e+110, 1.e-110], dtype=np.complex128)
        y = np.floor_divide(x**2, x)
        assert_equal(y, [1.e+110, 0], err_msg=msg)

    def test_floor_division_signed_zero(self):
        # Check that the sign bit is correctly set when dividing positive and
        # negative zero by one.
        x = np.zeros(10)
        assert_equal(np.signbit(x//1), 0)
        assert_equal(np.signbit((-x)//1), 1)

def floor_divide_and_remainder(x, y):
    return (np.floor_divide(x, y), np.remainder(x, y))


def _signs(dt):
    if dt in np.typecodes['UnsignedInteger']:
        return (+1,)
    else:
        return (+1, -1)


class TestRemainder(object):

    def test_remainder_basic(self):
        dt = np.typecodes['AllInteger'] + np.typecodes['Float']
        for op in [floor_divide_and_remainder, np.divmod]:
            for dt1, dt2 in itertools.product(dt, dt):
                for sg1, sg2 in itertools.product(_signs(dt1), _signs(dt2)):
                    fmt = 'op: %s, dt1: %s, dt2: %s, sg1: %s, sg2: %s'
                    msg = fmt % (op.__name__, dt1, dt2, sg1, sg2)
                    a = np.array(sg1*71, dtype=dt1)
                    b = np.array(sg2*19, dtype=dt2)
                    div, rem = op(a, b)
                    assert_equal(div*b + rem, a, err_msg=msg)
                    if sg2 == -1:
                        assert_(b < rem <= 0, msg)
                    else:
                        assert_(b > rem >= 0, msg)

    def test_float_remainder_exact(self):
        # test that float results are exact for small integers. This also
        # holds for the same integers scaled by powers of two.
        nlst = list(range(-127, 0))
        plst = list(range(1, 128))
        dividend = nlst + [0] + plst
        divisor = nlst + plst
        arg = list(itertools.product(dividend, divisor))
        tgt = list(divmod(*t) for t in arg)

        a, b = np.array(arg, dtype=int).T
        # convert exact integer results from Python to float so that
        # signed zero can be used, it is checked.
        tgtdiv, tgtrem = np.array(tgt, dtype=float).T
        tgtdiv = np.where((tgtdiv == 0.0) & ((b < 0) ^ (a < 0)), -0.0, tgtdiv)
        tgtrem = np.where((tgtrem == 0.0) & (b < 0), -0.0, tgtrem)

        for op in [floor_divide_and_remainder, np.divmod]:
            for dt in np.typecodes['Float']:
                msg = 'op: %s, dtype: %s' % (op.__name__, dt)
                fa = a.astype(dt)
                fb = b.astype(dt)
                div, rem = op(fa, fb)
                assert_equal(div, tgtdiv, err_msg=msg)
                assert_equal(rem, tgtrem, err_msg=msg)

    def test_float_remainder_roundoff(self):
        # gh-6127
        dt = np.typecodes['Float']
        for op in [floor_divide_and_remainder, np.divmod]:
            for dt1, dt2 in itertools.product(dt, dt):
                for sg1, sg2 in itertools.product((+1, -1), (+1, -1)):
                    fmt = 'op: %s, dt1: %s, dt2: %s, sg1: %s, sg2: %s'
                    msg = fmt % (op.__name__, dt1, dt2, sg1, sg2)
                    a = np.array(sg1*78*6e-8, dtype=dt1)
                    b = np.array(sg2*6e-8, dtype=dt2)
                    div, rem = op(a, b)
                    # Equal assertion should hold when fmod is used
                    assert_equal(div*b + rem, a, err_msg=msg)
                    if sg2 == -1:
                        assert_(b < rem <= 0, msg)
                    else:
                        assert_(b > rem >= 0, msg)

    def test_float_remainder_corner_cases(self):
        # Check remainder magnitude.
        for dt in np.typecodes['Float']:
            b = np.array(1.0, dtype=dt)
            a = np.nextafter(np.array(0.0, dtype=dt), -b)
            rem = np.remainder(a, b)
            assert_(rem <= b, 'dt: %s' % dt)
            rem = np.remainder(-a, -b)
            assert_(rem >= -b, 'dt: %s' % dt)

        # Check nans, inf
        with suppress_warnings() as sup:
            sup.filter(RuntimeWarning, "invalid value encountered in remainder")
            for dt in np.typecodes['Float']:
                fone = np.array(1.0, dtype=dt)
                fzer = np.array(0.0, dtype=dt)
                finf = np.array(np.inf, dtype=dt)
                fnan = np.array(np.nan, dtype=dt)
                rem = np.remainder(fone, fzer)
                assert_(np.isnan(rem), 'dt: %s, rem: %s' % (dt, rem))
                # MSVC 2008 returns NaN here, so disable the check.
                #rem = np.remainder(fone, finf)
                #assert_(rem == fone, 'dt: %s, rem: %s' % (dt, rem))
                rem = np.remainder(fone, fnan)
                assert_(np.isnan(rem), 'dt: %s, rem: %s' % (dt, rem))
                rem = np.remainder(finf, fone)
                assert_(np.isnan(rem), 'dt: %s, rem: %s' % (dt, rem))


class TestCbrt(object):
    def test_cbrt_scalar(self):
        assert_almost_equal((np.cbrt(np.float32(-2.5)**3)), -2.5)

    def test_cbrt(self):
        x = np.array([1., 2., -3., np.inf, -np.inf])
        assert_almost_equal(np.cbrt(x**3), x)

        assert_(np.isnan(np.cbrt(np.nan)))
        assert_equal(np.cbrt(np.inf), np.inf)
        assert_equal(np.cbrt(-np.inf), -np.inf)


class TestPower(object):
    def test_power_float(self):
        x = np.array([1., 2., 3.])
        assert_equal(x**0, [1., 1., 1.])
        assert_equal(x**1, x)
        assert_equal(x**2, [1., 4., 9.])
        y = x.copy()
        y **= 2
        assert_equal(y, [1., 4., 9.])
        assert_almost_equal(x**(-1), [1., 0.5, 1./3])
        assert_almost_equal(x**(0.5), [1., ncu.sqrt(2), ncu.sqrt(3)])

        for out, inp, msg in _gen_alignment_data(dtype=np.float32,
                                                 type='unary',
                                                 max_size=11):
            exp = [ncu.sqrt(i) for i in inp]
            assert_almost_equal(inp**(0.5), exp, err_msg=msg)
            np.sqrt(inp, out=out)
            assert_equal(out, exp, err_msg=msg)

        for out, inp, msg in _gen_alignment_data(dtype=np.float64,
                                                 type='unary',
                                                 max_size=7):
            exp = [ncu.sqrt(i) for i in inp]
            assert_almost_equal(inp**(0.5), exp, err_msg=msg)
            np.sqrt(inp, out=out)
            assert_equal(out, exp, err_msg=msg)

    def test_power_complex(self):
        x = np.array([1+2j, 2+3j, 3+4j])
        assert_equal(x**0, [1., 1., 1.])
        assert_equal(x**1, x)
        assert_almost_equal(x**2, [-3+4j, -5+12j, -7+24j])
        assert_almost_equal(x**3, [(1+2j)**3, (2+3j)**3, (3+4j)**3])
        assert_almost_equal(x**4, [(1+2j)**4, (2+3j)**4, (3+4j)**4])
        assert_almost_equal(x**(-1), [1/(1+2j), 1/(2+3j), 1/(3+4j)])
        assert_almost_equal(x**(-2), [1/(1+2j)**2, 1/(2+3j)**2, 1/(3+4j)**2])
        assert_almost_equal(x**(-3), [(-11+2j)/125, (-46-9j)/2197,
                                      (-117-44j)/15625])
        assert_almost_equal(x**(0.5), [ncu.sqrt(1+2j), ncu.sqrt(2+3j),
                                       ncu.sqrt(3+4j)])
        norm = 1./((x**14)[0])
        assert_almost_equal(x**14 * norm,
                [i * norm for i in [-76443+16124j, 23161315+58317492j,
                                    5583548873 + 2465133864j]])

        # Ticket #836
        def assert_complex_equal(x, y):
            assert_array_equal(x.real, y.real)
            assert_array_equal(x.imag, y.imag)

        for z in [complex(0, np.inf), complex(1, np.inf)]:
            z = np.array([z], dtype=np.complex_)
            with np.errstate(invalid="ignore"):
                assert_complex_equal(z**1, z)
                assert_complex_equal(z**2, z*z)
                assert_complex_equal(z**3, z*z*z)

    def test_power_zero(self):
        # ticket #1271
        zero = np.array([0j])
        one = np.array([1+0j])
        cnan = np.array([complex(np.nan, np.nan)])
        # FIXME cinf not tested.
        #cinf = np.array([complex(np.inf, 0)])

        def assert_complex_equal(x, y):
            x, y = np.asarray(x), np.asarray(y)
            assert_array_equal(x.real, y.real)
            assert_array_equal(x.imag, y.imag)

        # positive powers
        for p in [0.33, 0.5, 1, 1.5, 2, 3, 4, 5, 6.6]:
            assert_complex_equal(np.power(zero, p), zero)

        # zero power
        assert_complex_equal(np.power(zero, 0), one)
        with np.errstate(invalid="ignore"):
            assert_complex_equal(np.power(zero, 0+1j), cnan)

            # negative power
            for p in [0.33, 0.5, 1, 1.5, 2, 3, 4, 5, 6.6]:
                assert_complex_equal(np.power(zero, -p), cnan)
            assert_complex_equal(np.power(zero, -1+0.2j), cnan)

    def test_fast_power(self):
        x = np.array([1, 2, 3], np.int16)
        res = x**2.0
        assert_((x**2.00001).dtype is res.dtype)
        assert_array_equal(res, [1, 4, 9])
        # check the inplace operation on the casted copy doesn't mess with x
        assert_(not np.may_share_memory(res, x))
        assert_array_equal(x, [1, 2, 3])

        # Check that the fast path ignores 1-element not 0-d arrays
        res = x ** np.array([[[2]]])
        assert_equal(res.shape, (1, 1, 3))

    def test_integer_power(self):
        a = np.array([15, 15], 'i8')
        b = np.power(a, a)
        assert_equal(b, [437893890380859375, 437893890380859375])

    def test_integer_power_with_integer_zero_exponent(self):
        dtypes = np.typecodes['Integer']
        for dt in dtypes:
            arr = np.arange(-10, 10, dtype=dt)
            assert_equal(np.power(arr, 0), np.ones_like(arr))

        dtypes = np.typecodes['UnsignedInteger']
        for dt in dtypes:
            arr = np.arange(10, dtype=dt)
            assert_equal(np.power(arr, 0), np.ones_like(arr))

    def test_integer_power_of_1(self):
        dtypes = np.typecodes['AllInteger']
        for dt in dtypes:
            arr = np.arange(10, dtype=dt)
            assert_equal(np.power(1, arr), np.ones_like(arr))

    def test_integer_power_of_zero(self):
        dtypes = np.typecodes['AllInteger']
        for dt in dtypes:
            arr = np.arange(1, 10, dtype=dt)
            assert_equal(np.power(0, arr), np.zeros_like(arr))

    def test_integer_to_negative_power(self):
        dtypes = np.typecodes['Integer']
        for dt in dtypes:
            a = np.array([0, 1, 2, 3], dtype=dt)
            b = np.array([0, 1, 2, -3], dtype=dt)
            one = np.array(1, dtype=dt)
            minusone = np.array(-1, dtype=dt)
            assert_raises(ValueError, np.power, a, b)
            assert_raises(ValueError, np.power, a, minusone)
            assert_raises(ValueError, np.power, one, b)
            assert_raises(ValueError, np.power, one, minusone)


class TestFloat_power(object):
    def test_type_conversion(self):
        arg_type = '?bhilBHILefdgFDG'
        res_type = 'ddddddddddddgDDG'
        for dtin, dtout in zip(arg_type, res_type):
            msg = "dtin: %s, dtout: %s" % (dtin, dtout)
            arg = np.ones(1, dtype=dtin)
            res = np.float_power(arg, arg)
            assert_(res.dtype.name == np.dtype(dtout).name, msg)


class TestLog2(object):
    def test_log2_values(self):
        x = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024]
        y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
        for dt in ['f', 'd', 'g']:
            xf = np.array(x, dtype=dt)
            yf = np.array(y, dtype=dt)
            assert_almost_equal(np.log2(xf), yf)

    def test_log2_ints(self):
        # a good log2 implementation should provide this,
        # might fail on OS with bad libm
        for i in range(1, 65):
            v = np.log2(2.**i)
            assert_equal(v, float(i), err_msg='at exponent %d' % i)

    def test_log2_special(self):
        assert_equal(np.log2(1.), 0.)
        assert_equal(np.log2(np.inf), np.inf)
        assert_(np.isnan(np.log2(np.nan)))

        with warnings.catch_warnings(record=True) as w:
            warnings.filterwarnings('always', '', RuntimeWarning)
            assert_(np.isnan(np.log2(-1.)))
            assert_(np.isnan(np.log2(-np.inf)))
            assert_equal(np.log2(0.), -np.inf)
            assert_(w[0].category is RuntimeWarning)
            assert_(w[1].category is RuntimeWarning)
            assert_(w[2].category is RuntimeWarning)


class TestExp2(object):
    def test_exp2_values(self):
        x = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024]
        y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
        for dt in ['f', 'd', 'g']:
            xf = np.array(x, dtype=dt)
            yf = np.array(y, dtype=dt)
            assert_almost_equal(np.exp2(yf), xf)


class TestLogAddExp2(_FilterInvalids):
    # Need test for intermediate precisions
    def test_logaddexp2_values(self):
        x = [1, 2, 3, 4, 5]
        y = [5, 4, 3, 2, 1]
        z = [6, 6, 6, 6, 6]
        for dt, dec_ in zip(['f', 'd', 'g'], [6, 15, 15]):
            xf = np.log2(np.array(x, dtype=dt))
            yf = np.log2(np.array(y, dtype=dt))
            zf = np.log2(np.array(z, dtype=dt))
            assert_almost_equal(np.logaddexp2(xf, yf), zf, decimal=dec_)

    def test_logaddexp2_range(self):
        x = [1000000, -1000000, 1000200, -1000200]
        y = [1000200, -1000200, 1000000, -1000000]
        z = [1000200, -1000000, 1000200, -1000000]
        for dt in ['f', 'd', 'g']:
            logxf = np.array(x, dtype=dt)
            logyf = np.array(y, dtype=dt)
            logzf = np.array(z, dtype=dt)
            assert_almost_equal(np.logaddexp2(logxf, logyf), logzf)

    def test_inf(self):
        inf = np.inf
        x = [inf, -inf,  inf, -inf, inf, 1,  -inf,  1]
        y = [inf,  inf, -inf, -inf, 1,   inf, 1,   -inf]
        z = [inf,  inf,  inf, -inf, inf, inf, 1,    1]
        with np.errstate(invalid='raise'):
            for dt in ['f', 'd', 'g']:
                logxf = np.array(x, dtype=dt)
                logyf = np.array(y, dtype=dt)
                logzf = np.array(z, dtype=dt)
                assert_equal(np.logaddexp2(logxf, logyf), logzf)

    def test_nan(self):
        assert_(np.isnan(np.logaddexp2(np.nan, np.inf)))
        assert_(np.isnan(np.logaddexp2(np.inf, np.nan)))
        assert_(np.isnan(np.logaddexp2(np.nan, 0)))
        assert_(np.isnan(np.logaddexp2(0, np.nan)))
        assert_(np.isnan(np.logaddexp2(np.nan, np.nan)))


class TestLog(object):
    def test_log_values(self):
        x = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024]
        y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
        for dt in ['f', 'd', 'g']:
            log2_ = 0.69314718055994530943
            xf = np.array(x, dtype=dt)
            yf = np.array(y, dtype=dt)*log2_
            assert_almost_equal(np.log(xf), yf)


class TestExp(object):
    def test_exp_values(self):
        x = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024]
        y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
        for dt in ['f', 'd', 'g']:
            log2_ = 0.69314718055994530943
            xf = np.array(x, dtype=dt)
            yf = np.array(y, dtype=dt)*log2_
            assert_almost_equal(np.exp(yf), xf)


class TestLogAddExp(_FilterInvalids):
    def test_logaddexp_values(self):
        x = [1, 2, 3, 4, 5]
        y = [5, 4, 3, 2, 1]
        z = [6, 6, 6, 6, 6]
        for dt, dec_ in zip(['f', 'd', 'g'], [6, 15, 15]):
            xf = np.log(np.array(x, dtype=dt))
            yf = np.log(np.array(y, dtype=dt))
            zf = np.log(np.array(z, dtype=dt))
            assert_almost_equal(np.logaddexp(xf, yf), zf, decimal=dec_)

    def test_logaddexp_range(self):
        x = [1000000, -1000000, 1000200, -1000200]
        y = [1000200, -1000200, 1000000, -1000000]
        z = [1000200, -1000000, 1000200, -1000000]
        for dt in ['f', 'd', 'g']:
            logxf = np.array(x, dtype=dt)
            logyf = np.array(y, dtype=dt)
            logzf = np.array(z, dtype=dt)
            assert_almost_equal(np.logaddexp(logxf, logyf), logzf)

    def test_inf(self):
        inf = np.inf
        x = [inf, -inf,  inf, -inf, inf, 1,  -inf,  1]
        y = [inf,  inf, -inf, -inf, 1,   inf, 1,   -inf]
        z = [inf,  inf,  inf, -inf, inf, inf, 1,    1]
        with np.errstate(invalid='raise'):
            for dt in ['f', 'd', 'g']:
                logxf = np.array(x, dtype=dt)
                logyf = np.array(y, dtype=dt)
                logzf = np.array(z, dtype=dt)
                assert_equal(np.logaddexp(logxf, logyf), logzf)

    def test_nan(self):
        assert_(np.isnan(np.logaddexp(np.nan, np.inf)))
        assert_(np.isnan(np.logaddexp(np.inf, np.nan)))
        assert_(np.isnan(np.logaddexp(np.nan, 0)))
        assert_(np.isnan(np.logaddexp(0, np.nan)))
        assert_(np.isnan(np.logaddexp(np.nan, np.nan)))

    def test_reduce(self):
        assert_equal(np.logaddexp.identity, -np.inf)
        assert_equal(np.logaddexp.reduce([]), -np.inf)


class TestLog1p(object):
    def test_log1p(self):
        assert_almost_equal(ncu.log1p(0.2), ncu.log(1.2))
        assert_almost_equal(ncu.log1p(1e-6), ncu.log(1+1e-6))

    def test_special(self):
        with np.errstate(invalid="ignore", divide="ignore"):
            assert_equal(ncu.log1p(np.nan), np.nan)
            assert_equal(ncu.log1p(np.inf), np.inf)
            assert_equal(ncu.log1p(-1.), -np.inf)
            assert_equal(ncu.log1p(-2.), np.nan)
            assert_equal(ncu.log1p(-np.inf), np.nan)


class TestExpm1(object):
    def test_expm1(self):
        assert_almost_equal(ncu.expm1(0.2), ncu.exp(0.2)-1)
        assert_almost_equal(ncu.expm1(1e-6), ncu.exp(1e-6)-1)

    def test_special(self):
        assert_equal(ncu.expm1(np.inf), np.inf)
        assert_equal(ncu.expm1(0.), 0.)
        assert_equal(ncu.expm1(-0.), -0.)
        assert_equal(ncu.expm1(np.inf), np.inf)
        assert_equal(ncu.expm1(-np.inf), -1.)


class TestHypot(object):
    def test_simple(self):
        assert_almost_equal(ncu.hypot(1, 1), ncu.sqrt(2))
        assert_almost_equal(ncu.hypot(0, 0), 0)

    def test_reduce(self):
        assert_almost_equal(ncu.hypot.reduce([3.0, 4.0]), 5.0)
        assert_almost_equal(ncu.hypot.reduce([3.0, 4.0, 0]), 5.0)
        assert_almost_equal(ncu.hypot.reduce([9.0, 12.0, 20.0]), 25.0)
        assert_equal(ncu.hypot.reduce([]), 0.0)


def assert_hypot_isnan(x, y):
    with np.errstate(invalid='ignore'):
        assert_(np.isnan(ncu.hypot(x, y)),
                "hypot(%s, %s) is %s, not nan" % (x, y, ncu.hypot(x, y)))


def assert_hypot_isinf(x, y):
    with np.errstate(invalid='ignore'):
        assert_(np.isinf(ncu.hypot(x, y)),
                "hypot(%s, %s) is %s, not inf" % (x, y, ncu.hypot(x, y)))


class TestHypotSpecialValues(object):
    def test_nan_outputs(self):
        assert_hypot_isnan(np.nan, np.nan)
        assert_hypot_isnan(np.nan, 1)

    def test_nan_outputs2(self):
        assert_hypot_isinf(np.nan, np.inf)
        assert_hypot_isinf(np.inf, np.nan)
        assert_hypot_isinf(np.inf, 0)
        assert_hypot_isinf(0, np.inf)
        assert_hypot_isinf(np.inf, np.inf)
        assert_hypot_isinf(np.inf, 23.0)

    def test_no_fpe(self):
        assert_no_warnings(ncu.hypot, np.inf, 0)


def assert_arctan2_isnan(x, y):
    assert_(np.isnan(ncu.arctan2(x, y)), "arctan(%s, %s) is %s, not nan" % (x, y, ncu.arctan2(x, y)))


def assert_arctan2_ispinf(x, y):
    assert_((np.isinf(ncu.arctan2(x, y)) and ncu.arctan2(x, y) > 0), "arctan(%s, %s) is %s, not +inf" % (x, y, ncu.arctan2(x, y)))


def assert_arctan2_isninf(x, y):
    assert_((np.isinf(ncu.arctan2(x, y)) and ncu.arctan2(x, y) < 0), "arctan(%s, %s) is %s, not -inf" % (x, y, ncu.arctan2(x, y)))


def assert_arctan2_ispzero(x, y):
    assert_((ncu.arctan2(x, y) == 0 and not np.signbit(ncu.arctan2(x, y))), "arctan(%s, %s) is %s, not +0" % (x, y, ncu.arctan2(x, y)))


def assert_arctan2_isnzero(x, y):
    assert_((ncu.arctan2(x, y) == 0 and np.signbit(ncu.arctan2(x, y))), "arctan(%s, %s) is %s, not -0" % (x, y, ncu.arctan2(x, y)))


class TestArctan2SpecialValues(object):
    def test_one_one(self):
        # atan2(1, 1) returns pi/4.
        assert_almost_equal(ncu.arctan2(1, 1), 0.25 * np.pi)
        assert_almost_equal(ncu.arctan2(-1, 1), -0.25 * np.pi)
        assert_almost_equal(ncu.arctan2(1, -1), 0.75 * np.pi)

    def test_zero_nzero(self):
        # atan2(+-0, -0) returns +-pi.
        assert_almost_equal(ncu.arctan2(np.PZERO, np.NZERO), np.pi)
        assert_almost_equal(ncu.arctan2(np.NZERO, np.NZERO), -np.pi)

    def test_zero_pzero(self):
        # atan2(+-0, +0) returns +-0.
        assert_arctan2_ispzero(np.PZERO, np.PZERO)
        assert_arctan2_isnzero(np.NZERO, np.PZERO)

    def test_zero_negative(self):
        # atan2(+-0, x) returns +-pi for x < 0.
        assert_almost_equal(ncu.arctan2(np.PZERO, -1), np.pi)
        assert_almost_equal(ncu.arctan2(np.NZERO, -1), -np.pi)

    def test_zero_positive(self):
        # atan2(+-0, x) returns +-0 for x > 0.
        assert_arctan2_ispzero(np.PZERO, 1)
        assert_arctan2_isnzero(np.NZERO, 1)

    def test_positive_zero(self):
        # atan2(y, +-0) returns +pi/2 for y > 0.
        assert_almost_equal(ncu.arctan2(1, np.PZERO), 0.5 * np.pi)
        assert_almost_equal(ncu.arctan2(1, np.NZERO), 0.5 * np.pi)

    def test_negative_zero(self):
        # atan2(y, +-0) returns -pi/2 for y < 0.
        assert_almost_equal(ncu.arctan2(-1, np.PZERO), -0.5 * np.pi)
        assert_almost_equal(ncu.arctan2(-1, np.NZERO), -0.5 * np.pi)

    def test_any_ninf(self):
        # atan2(+-y, -infinity) returns +-pi for finite y > 0.
        assert_almost_equal(ncu.arctan2(1, np.NINF),  np.pi)
        assert_almost_equal(ncu.arctan2(-1, np.NINF), -np.pi)

    def test_any_pinf(self):
        # atan2(+-y, +infinity) returns +-0 for finite y > 0.
        assert_arctan2_ispzero(1, np.inf)
        assert_arctan2_isnzero(-1, np.inf)

    def test_inf_any(self):
        # atan2(+-infinity, x) returns +-pi/2 for finite x.
        assert_almost_equal(ncu.arctan2( np.inf, 1),  0.5 * np.pi)
        assert_almost_equal(ncu.arctan2(-np.inf, 1), -0.5 * np.pi)

    def test_inf_ninf(self):
        # atan2(+-infinity, -infinity) returns +-3*pi/4.
        assert_almost_equal(ncu.arctan2( np.inf, -np.inf),  0.75 * np.pi)
        assert_almost_equal(ncu.arctan2(-np.inf, -np.inf), -0.75 * np.pi)

    def test_inf_pinf(self):
        # atan2(+-infinity, +infinity) returns +-pi/4.
        assert_almost_equal(ncu.arctan2( np.inf, np.inf),  0.25 * np.pi)
        assert_almost_equal(ncu.arctan2(-np.inf, np.inf), -0.25 * np.pi)

    def test_nan_any(self):
        # atan2(nan, x) returns nan for any x, including inf
        assert_arctan2_isnan(np.nan, np.inf)
        assert_arctan2_isnan(np.inf, np.nan)
        assert_arctan2_isnan(np.nan, np.nan)


class TestLdexp(object):
    def _check_ldexp(self, tp):
        assert_almost_equal(ncu.ldexp(np.array(2., np.float32),
                                      np.array(3, tp)), 16.)
        assert_almost_equal(ncu.ldexp(np.array(2., np.float64),
                                      np.array(3, tp)), 16.)
        assert_almost_equal(ncu.ldexp(np.array(2., np.longdouble),
                                      np.array(3, tp)), 16.)

    def test_ldexp(self):
        # The default Python int type should work
        assert_almost_equal(ncu.ldexp(2., 3),  16.)
        # The following int types should all be accepted
        self._check_ldexp(np.int8)
        self._check_ldexp(np.int16)
        self._check_ldexp(np.int32)
        self._check_ldexp('i')
        self._check_ldexp('l')

    def test_ldexp_overflow(self):
        # silence warning emitted on overflow
        with np.errstate(over="ignore"):
            imax = np.iinfo(np.dtype('l')).max
            imin = np.iinfo(np.dtype('l')).min
            assert_equal(ncu.ldexp(2., imax), np.inf)
            assert_equal(ncu.ldexp(2., imin), 0)


class TestMaximum(_FilterInvalids):
    def test_reduce(self):
        dflt = np.typecodes['AllFloat']
        dint = np.typecodes['AllInteger']
        seq1 = np.arange(11)
        seq2 = seq1[::-1]
        func = np.maximum.reduce
        for dt in dint:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 10)
            assert_equal(func(tmp2), 10)
        for dt in dflt:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 10)
            assert_equal(func(tmp2), 10)
            tmp1[::2] = np.nan
            tmp2[::2] = np.nan
            assert_equal(func(tmp1), np.nan)
            assert_equal(func(tmp2), np.nan)

    def test_reduce_complex(self):
        assert_equal(np.maximum.reduce([1, 2j]), 1)
        assert_equal(np.maximum.reduce([1+3j, 2j]), 1+3j)

    def test_float_nans(self):
        nan = np.nan
        arg1 = np.array([0,   nan, nan])
        arg2 = np.array([nan, 0,   nan])
        out = np.array([nan, nan, nan])
        assert_equal(np.maximum(arg1, arg2), out)

    def test_object_nans(self):
        # Multiple checks to give this a chance to
        # fail if cmp is used instead of rich compare.
        # Failure cannot be guaranteed.
        for i in range(1):
            x = np.array(float('nan'), object)
            y = 1.0
            z = np.array(float('nan'), object)
            assert_(np.maximum(x, y) == 1.0)
            assert_(np.maximum(z, y) == 1.0)

    def test_complex_nans(self):
        nan = np.nan
        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)]:
            arg1 = np.array([0, cnan, cnan], dtype=complex)
            arg2 = np.array([cnan, 0, cnan], dtype=complex)
            out = np.array([nan, nan, nan], dtype=complex)
            assert_equal(np.maximum(arg1, arg2), out)

    def test_object_array(self):
        arg1 = np.arange(5, dtype=object)
        arg2 = arg1 + 1
        assert_equal(np.maximum(arg1, arg2), arg2)


class TestMinimum(_FilterInvalids):
    def test_reduce(self):
        dflt = np.typecodes['AllFloat']
        dint = np.typecodes['AllInteger']
        seq1 = np.arange(11)
        seq2 = seq1[::-1]
        func = np.minimum.reduce
        for dt in dint:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 0)
            assert_equal(func(tmp2), 0)
        for dt in dflt:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 0)
            assert_equal(func(tmp2), 0)
            tmp1[::2] = np.nan
            tmp2[::2] = np.nan
            assert_equal(func(tmp1), np.nan)
            assert_equal(func(tmp2), np.nan)

    def test_reduce_complex(self):
        assert_equal(np.minimum.reduce([1, 2j]), 2j)
        assert_equal(np.minimum.reduce([1+3j, 2j]), 2j)

    def test_float_nans(self):
        nan = np.nan
        arg1 = np.array([0,   nan, nan])
        arg2 = np.array([nan, 0,   nan])
        out = np.array([nan, nan, nan])
        assert_equal(np.minimum(arg1, arg2), out)

    def test_object_nans(self):
        # Multiple checks to give this a chance to
        # fail if cmp is used instead of rich compare.
        # Failure cannot be guaranteed.
        for i in range(1):
            x = np.array(float('nan'), object)
            y = 1.0
            z = np.array(float('nan'), object)
            assert_(np.minimum(x, y) == 1.0)
            assert_(np.minimum(z, y) == 1.0)

    def test_complex_nans(self):
        nan = np.nan
        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)]:
            arg1 = np.array([0, cnan, cnan], dtype=complex)
            arg2 = np.array([cnan, 0, cnan], dtype=complex)
            out = np.array([nan, nan, nan], dtype=complex)
            assert_equal(np.minimum(arg1, arg2), out)

    def test_object_array(self):
        arg1 = np.arange(5, dtype=object)
        arg2 = arg1 + 1
        assert_equal(np.minimum(arg1, arg2), arg1)


class TestFmax(_FilterInvalids):
    def test_reduce(self):
        dflt = np.typecodes['AllFloat']
        dint = np.typecodes['AllInteger']
        seq1 = np.arange(11)
        seq2 = seq1[::-1]
        func = np.fmax.reduce
        for dt in dint:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 10)
            assert_equal(func(tmp2), 10)
        for dt in dflt:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 10)
            assert_equal(func(tmp2), 10)
            tmp1[::2] = np.nan
            tmp2[::2] = np.nan
            assert_equal(func(tmp1), 9)
            assert_equal(func(tmp2), 9)

    def test_reduce_complex(self):
        assert_equal(np.fmax.reduce([1, 2j]), 1)
        assert_equal(np.fmax.reduce([1+3j, 2j]), 1+3j)

    def test_float_nans(self):
        nan = np.nan
        arg1 = np.array([0,   nan, nan])
        arg2 = np.array([nan, 0,   nan])
        out = np.array([0,   0,   nan])
        assert_equal(np.fmax(arg1, arg2), out)

    def test_complex_nans(self):
        nan = np.nan
        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)]:
            arg1 = np.array([0, cnan, cnan], dtype=complex)
            arg2 = np.array([cnan, 0, cnan], dtype=complex)
            out = np.array([0,    0, nan], dtype=complex)
            assert_equal(np.fmax(arg1, arg2), out)


class TestFmin(_FilterInvalids):
    def test_reduce(self):
        dflt = np.typecodes['AllFloat']
        dint = np.typecodes['AllInteger']
        seq1 = np.arange(11)
        seq2 = seq1[::-1]
        func = np.fmin.reduce
        for dt in dint:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 0)
            assert_equal(func(tmp2), 0)
        for dt in dflt:
            tmp1 = seq1.astype(dt)
            tmp2 = seq2.astype(dt)
            assert_equal(func(tmp1), 0)
            assert_equal(func(tmp2), 0)
            tmp1[::2] = np.nan
            tmp2[::2] = np.nan
            assert_equal(func(tmp1), 1)
            assert_equal(func(tmp2), 1)

    def test_reduce_complex(self):
        assert_equal(np.fmin.reduce([1, 2j]), 2j)
        assert_equal(np.fmin.reduce([1+3j, 2j]), 2j)

    def test_float_nans(self):
        nan = np.nan
        arg1 = np.array([0,   nan, nan])
        arg2 = np.array([nan, 0,   nan])
        out = np.array([0,   0,   nan])
        assert_equal(np.fmin(arg1, arg2), out)

    def test_complex_nans(self):
        nan = np.nan
        for cnan in [complex(nan, 0), complex(0, nan), complex(nan, nan)]:
            arg1 = np.array([0, cnan, cnan], dtype=complex)
            arg2 = np.array([cnan, 0, cnan], dtype=complex)
            out = np.array([0,    0, nan], dtype=complex)
            assert_equal(np.fmin(arg1, arg2), out)


class TestBool(object):
    def test_exceptions(self):
        a = np.ones(1, dtype=np.bool_)
        assert_raises(TypeError, np.negative, a)
        assert_raises(TypeError, np.positive, a)
        assert_raises(TypeError, np.subtract, a, a)

    def test_truth_table_logical(self):
        # 2, 3 and 4 serves as true values
        input1 = [0, 0, 3, 2]
        input2 = [0, 4, 0, 2]

        typecodes = (np.typecodes['AllFloat']
                     + np.typecodes['AllInteger']
                     + '?')     # boolean
        for dtype in map(np.dtype, typecodes):
            arg1 = np.asarray(input1, dtype=dtype)
            arg2 = np.asarray(input2, dtype=dtype)

            # OR
            out = [False, True, True, True]
            for func in (np.logical_or, np.maximum):
                assert_equal(func(arg1, arg2).astype(bool), out)
            # AND
            out = [False, False, False, True]
            for func in (np.logical_and, np.minimum):
                assert_equal(func(arg1, arg2).astype(bool), out)
            # XOR
            out = [False, True, True, False]
            for func in (np.logical_xor, np.not_equal):
                assert_equal(func(arg1, arg2).astype(bool), out)

    def test_truth_table_bitwise(self):
        arg1 = [False, False, True, True]
        arg2 = [False, True, False, True]

        out = [False, True, True, True]
        assert_equal(np.bitwise_or(arg1, arg2), out)

        out = [False, False, False, True]
        assert_equal(np.bitwise_and(arg1, arg2), out)

        out = [False, True, True, False]
        assert_equal(np.bitwise_xor(arg1, arg2), out)

    def test_reduce(self):
        none = np.array([0, 0, 0, 0], bool)
        some = np.array([1, 0, 1, 1], bool)
        every = np.array([1, 1, 1, 1], bool)
        empty = np.array([], bool)

        arrs = [none, some, every, empty]

        for arr in arrs:
            assert_equal(np.logical_and.reduce(arr), all(arr))

        for arr in arrs:
            assert_equal(np.logical_or.reduce(arr), any(arr))

        for arr in arrs:
            assert_equal(np.logical_xor.reduce(arr), arr.sum() % 2 == 1)


class TestBitwiseUFuncs(object):

    bitwise_types = [np.dtype(c) for c in '?' + 'bBhHiIlLqQ' + 'O']

    def test_values(self):
        for dt in self.bitwise_types:
            zeros = np.array([0], dtype=dt)
            ones = np.array([-1], dtype=dt)
            msg = "dt = '%s'" % dt.char

            assert_equal(np.bitwise_not(zeros), ones, err_msg=msg)
            assert_equal(np.bitwise_not(ones), zeros, err_msg=msg)

            assert_equal(np.bitwise_or(zeros, zeros), zeros, err_msg=msg)
            assert_equal(np.bitwise_or(zeros, ones), ones, err_msg=msg)
            assert_equal(np.bitwise_or(ones, zeros), ones, err_msg=msg)
            assert_equal(np.bitwise_or(ones, ones), ones, err_msg=msg)

            assert_equal(np.bitwise_xor(zeros, zeros), zeros, err_msg=msg)
            assert_equal(np.bitwise_xor(zeros, ones), ones, err_msg=msg)
            assert_equal(np.bitwise_xor(ones, zeros), ones, err_msg=msg)
            assert_equal(np.bitwise_xor(ones, ones), zeros, err_msg=msg)

            assert_equal(np.bitwise_and(zeros, zeros), zeros, err_msg=msg)
            assert_equal(np.bitwise_and(zeros, ones), zeros, err_msg=msg)
            assert_equal(np.bitwise_and(ones, zeros), zeros, err_msg=msg)
            assert_equal(np.bitwise_and(ones, ones), ones, err_msg=msg)

    def test_types(self):
        for dt in self.bitwise_types:
            zeros = np.array([0], dtype=dt)
            ones = np.array([-1], dtype=dt)
            msg = "dt = '%s'" % dt.char

            assert_(np.bitwise_not(zeros).dtype == dt, msg)
            assert_(np.bitwise_or(zeros, zeros).dtype == dt, msg)
            assert_(np.bitwise_xor(zeros, zeros).dtype == dt, msg)
            assert_(np.bitwise_and(zeros, zeros).dtype == dt, msg)

    def test_identity(self):
        assert_(np.bitwise_or.identity == 0, 'bitwise_or')
        assert_(np.bitwise_xor.identity == 0, 'bitwise_xor')
        assert_(np.bitwise_and.identity == -1, 'bitwise_and')

    def test_reduction(self):
        binary_funcs = (np.bitwise_or, np.bitwise_xor, np.bitwise_and)

        for dt in self.bitwise_types:
            zeros = np.array([0], dtype=dt)
            ones = np.array([-1], dtype=dt)
            for f in binary_funcs:
                msg = "dt: '%s', f: '%s'" % (dt, f)
                assert_equal(f.reduce(zeros), zeros, err_msg=msg)
                assert_equal(f.reduce(ones), ones, err_msg=msg)

        # Test empty reduction, no object dtype
        for dt in self.bitwise_types[:-1]:
            # No object array types
            empty = np.array([], dtype=dt)
            for f in binary_funcs:
                msg = "dt: '%s', f: '%s'" % (dt, f)
                tgt = np.array(f.identity, dtype=dt)
                res = f.reduce(empty)
                assert_equal(res, tgt, err_msg=msg)
                assert_(res.dtype == tgt.dtype, msg)

        # Empty object arrays use the identity.  Note that the types may
        # differ, the actual type used is determined by the assign_identity
        # function and is not the same as the type returned by the identity
        # method.
        for f in binary_funcs:
            msg = "dt: '%s'" % (f,)
            empty = np.array([], dtype=object)
            tgt = f.identity
            res = f.reduce(empty)
            assert_equal(res, tgt, err_msg=msg)

        # Non-empty object arrays do not use the identity
        for f in binary_funcs:
            msg = "dt: '%s'" % (f,)
            btype = np.array([True], dtype=object)
            assert_(type(f.reduce(btype)) is bool, msg)


class TestInt(object):
    def test_logical_not(self):
        x = np.ones(10, dtype=np.int16)
        o = np.ones(10 * 2, dtype=bool)
        tgt = o.copy()
        tgt[::2] = False
        os = o[::2]
        assert_array_equal(np.logical_not(x, out=os), False)
        assert_array_equal(o, tgt)


class TestFloatingPoint(object):
    def test_floating_point(self):
        assert_equal(ncu.FLOATING_POINT_SUPPORT, 1)


class TestDegrees(object):
    def test_degrees(self):
        assert_almost_equal(ncu.degrees(np.pi), 180.0)
        assert_almost_equal(ncu.degrees(-0.5*np.pi), -90.0)


class TestRadians(object):
    def test_radians(self):
        assert_almost_equal(ncu.radians(180.0), np.pi)
        assert_almost_equal(ncu.radians(-90.0), -0.5*np.pi)


class TestHeavside(object):
    def test_heaviside(self):
        x = np.array([[-30.0, -0.1, 0.0, 0.2], [7.5, np.nan, np.inf, -np.inf]])
        expectedhalf = np.array([[0.0, 0.0, 0.5, 1.0], [1.0, np.nan, 1.0, 0.0]])
        expected1 = expectedhalf.copy()
        expected1[0, 2] = 1

        h = ncu.heaviside(x, 0.5)
        assert_equal(h, expectedhalf)

        h = ncu.heaviside(x, 1.0)
        assert_equal(h, expected1)

        x = x.astype(np.float32)

        h = ncu.heaviside(x, np.float32(0.5))
        assert_equal(h, expectedhalf.astype(np.float32))

        h = ncu.heaviside(x, np.float32(1.0))
        assert_equal(h, expected1.astype(np.float32))


class TestSign(object):
    def test_sign(self):
        a = np.array([np.inf, -np.inf, np.nan, 0.0, 3.0, -3.0])
        out = np.zeros(a.shape)
        tgt = np.array([1., -1., np.nan, 0.0, 1.0, -1.0])

        with np.errstate(invalid='ignore'):
            res = ncu.sign(a)
            assert_equal(res, tgt)
            res = ncu.sign(a, out)
            assert_equal(res, tgt)
            assert_equal(out, tgt)

    def test_sign_dtype_object(self):
        # In reference to github issue #6229

        foo = np.array([-.1, 0, .1])
        a = np.sign(foo.astype(object))
        b = np.sign(foo)

        assert_array_equal(a, b)

    def test_sign_dtype_nan_object(self):
        # In reference to github issue #6229
        def test_nan():
            foo = np.array([np.nan])
            # FIXME: a not used
            a = np.sign(foo.astype(object))

        assert_raises(TypeError, test_nan)

class TestMinMax(object):
    def test_minmax_blocked(self):
        # simd tests on max/min, test all alignments, slow but important
        # for 2 * vz + 2 * (vs - 1) + 1 (unrolled once)
        for dt, sz in [(np.float32, 15), (np.float64, 7)]:
            for out, inp, msg in _gen_alignment_data(dtype=dt, type='unary',
                                                     max_size=sz):
                for i in range(inp.size):
                    inp[:] = np.arange(inp.size, dtype=dt)
                    inp[i] = np.nan
                    emsg = lambda: '%r\n%s' % (inp, msg)
                    with suppress_warnings() as sup:
                        sup.filter(RuntimeWarning,
                                   "invalid value encountered in reduce")
                        assert_(np.isnan(inp.max()), msg=emsg)
                        assert_(np.isnan(inp.min()), msg=emsg)

                    inp[i] = 1e10
                    assert_equal(inp.max(), 1e10, err_msg=msg)
                    inp[i] = -1e10
                    assert_equal(inp.min(), -1e10, err_msg=msg)

    def test_lower_align(self):
        # check data that is not aligned to element size
        # i.e doubles are aligned to 4 bytes on i386
        d = np.zeros(23 * 8, dtype=np.int8)[4:-4].view(np.float64)
        assert_equal(d.max(), d[0])
        assert_equal(d.min(), d[0])

    def test_reduce_reorder(self):
        # gh 10370, 11029 Some compilers reorder the call to npy_getfloatstatus
        # and put it before the call to an intrisic function that causes
        # invalid status to be set. Also make sure warnings are not emitted
        for n in (2, 4, 8, 16, 32):
            for dt in (np.float32, np.float16, np.complex64):
                for r in np.diagflat(np.array([np.nan] * n, dtype=dt)):
                    assert_equal(np.min(r), np.nan)

    def test_minimize_no_warns(self):
        a = np.minimum(np.nan, 1)
        assert_equal(a, np.nan)


class TestAbsoluteNegative(object):
    def test_abs_neg_blocked(self):
        # simd tests on abs, test all alignments for vz + 2 * (vs - 1) + 1
        for dt, sz in [(np.float32, 11), (np.float64, 5)]:
            for out, inp, msg in _gen_alignment_data(dtype=dt, type='unary',
                                                     max_size=sz):
                tgt = [ncu.absolute(i) for i in inp]
                np.absolute(inp, out=out)
                assert_equal(out, tgt, err_msg=msg)
                assert_((out >= 0).all())

                tgt = [-1*(i) for i in inp]
                np.negative(inp, out=out)
                assert_equal(out, tgt, err_msg=msg)

                for v in [np.nan, -np.inf, np.inf]:
                    for i in range(inp.size):
                        d = np.arange(inp.size, dtype=dt)
                        inp[:] = -d
                        inp[i] = v
                        d[i] = -v if v == -np.inf else v
                        assert_array_equal(np.abs(inp), d, err_msg=msg)
                        np.abs(inp, out=out)
                        assert_array_equal(out, d, err_msg=msg)

                        assert_array_equal(-inp, -1*inp, err_msg=msg)
                        d = -1 * inp
                        np.negative(inp, out=out)
                        assert_array_equal(out, d, err_msg=msg)

    def test_lower_align(self):
        # check data that is not aligned to element size
        # i.e doubles are aligned to 4 bytes on i386
        d = np.zeros(23 * 8, dtype=np.int8)[4:-4].view(np.float64)
        assert_equal(np.abs(d), d)
        assert_equal(np.negative(d), -d)
        np.negative(d, out=d)
        np.negative(np.ones_like(d), out=d)
        np.abs(d, out=d)
        np.abs(np.ones_like(d), out=d)


class TestPositive(object):
    def test_valid(self):
        valid_dtypes = [int, float, complex, object]
        for dtype in valid_dtypes:
            x = np.arange(5, dtype=dtype)
            result = np.positive(x)
            assert_equal(x, result, err_msg=str(dtype))

    def test_invalid(self):
        with assert_raises(TypeError):
            np.positive(True)
        with assert_raises(TypeError):
            np.positive(np.datetime64('2000-01-01'))
        with assert_raises(TypeError):
            np.positive(np.array(['foo'], dtype=str))
        with assert_raises(TypeError):
            np.positive(np.array(['bar'], dtype=object))


class TestSpecialMethods(object):
    def test_wrap(self):

        class with_wrap(object):
            def __array__(self):
                return np.zeros(1)

            def __array_wrap__(self, arr, context):
                r = with_wrap()
                r.arr = arr
                r.context = context
                return r

        a = with_wrap()
        x = ncu.minimum(a, a)
        assert_equal(x.arr, np.zeros(1))
        func, args, i = x.context
        assert_(func is ncu.minimum)
        assert_equal(len(args), 2)
        assert_equal(args[0], a)
        assert_equal(args[1], a)
        assert_equal(i, 0)

    def test_wrap_and_prepare_out(self):
        # Calling convention for out should not affect how special methods are
        # called

        class StoreArrayPrepareWrap(np.ndarray):
            _wrap_args = None
            _prepare_args = None
            def __new__(cls):
                return np.empty(()).view(cls)
            def __array_wrap__(self, obj, context):
                self._wrap_args = context[1]
                return obj
            def __array_prepare__(self, obj, context):
                self._prepare_args = context[1]
                return obj
            @property
            def args(self):
                # We need to ensure these are fetched at the same time, before
                # any other ufuncs are calld by the assertions
                return (self._prepare_args, self._wrap_args)
            def __repr__(self):
                return "a"  # for short test output

        def do_test(f_call, f_expected):
            a = StoreArrayPrepareWrap()
            f_call(a)
            p, w = a.args
            expected = f_expected(a)
            try:
                assert_equal(p, expected)
                assert_equal(w, expected)
            except AssertionError as e:
                # assert_equal produces truly useless error messages
                raise AssertionError("\n".join([
                    "Bad arguments passed in ufunc call",
                    " expected:              {}".format(expected),
                    " __array_prepare__ got: {}".format(p),
                    " __array_wrap__ got:    {}".format(w)
                ]))

        # method not on the out argument
        do_test(lambda a: np.add(a, 0),              lambda a: (a, 0))
        do_test(lambda a: np.add(a, 0, None),        lambda a: (a, 0))
        do_test(lambda a: np.add(a, 0, out=None),    lambda a: (a, 0))
        do_test(lambda a: np.add(a, 0, out=(None,)), lambda a: (a, 0))

        # method on the out argument
        do_test(lambda a: np.add(0, 0, a),           lambda a: (0, 0, a))
        do_test(lambda a: np.add(0, 0, out=a),       lambda a: (0, 0, a))
        do_test(lambda a: np.add(0, 0, out=(a,)),    lambda a: (0, 0, a))

    def test_wrap_with_iterable(self):
        # test fix for bug #1026:

        class with_wrap(np.ndarray):
            __array_priority__ = 10

            def __new__(cls):
                return np.asarray(1).view(cls).copy()

            def __array_wrap__(self, arr, context):
                return arr.view(type(self))

        a = with_wrap()
        x = ncu.multiply(a, (1, 2, 3))
        assert_(isinstance(x, with_wrap))
        assert_array_equal(x, np.array((1, 2, 3)))

    def test_priority_with_scalar(self):
        # test fix for bug #826:

        class A(np.ndarray):
            __array_priority__ = 10

            def __new__(cls):
                return np.asarray(1.0, 'float64').view(cls).copy()

        a = A()
        x = np.float64(1)*a
        assert_(isinstance(x, A))
        assert_array_equal(x, np.array(1))

    def test_old_wrap(self):

        class with_wrap(object):
            def __array__(self):
                return np.zeros(1)

            def __array_wrap__(self, arr):
                r = with_wrap()
                r.arr = arr
                return r

        a = with_wrap()
        x = ncu.minimum(a, a)
        assert_equal(x.arr, np.zeros(1))

    def test_priority(self):

        class A(object):
            def __array__(self):
                return np.zeros(1)

            def __array_wrap__(self, arr, context):
                r = type(self)()
                r.arr = arr
                r.context = context
                return r

        class B(A):
            __array_priority__ = 20.

        class C(A):
            __array_priority__ = 40.

        x = np.zeros(1)
        a = A()
        b = B()
        c = C()
        f = ncu.minimum
        assert_(type(f(x, x)) is np.ndarray)
        assert_(type(f(x, a)) is A)
        assert_(type(f(x, b)) is B)
        assert_(type(f(x, c)) is C)
        assert_(type(f(a, x)) is A)
        assert_(type(f(b, x)) is B)
        assert_(type(f(c, x)) is C)

        assert_(type(f(a, a)) is A)
        assert_(type(f(a, b)) is B)
        assert_(type(f(b, a)) is B)
        assert_(type(f(b, b)) is B)
        assert_(type(f(b, c)) is C)
        assert_(type(f(c, b)) is C)
        assert_(type(f(c, c)) is C)

        assert_(type(ncu.exp(a) is A))
        assert_(type(ncu.exp(b) is B))
        assert_(type(ncu.exp(c) is C))

    def test_failing_wrap(self):

        class A(object):
            def __array__(self):
                return np.zeros(2)

            def __array_wrap__(self, arr, context):
                raise RuntimeError

        a = A()
        assert_raises(RuntimeError, ncu.maximum, a, a)
        assert_raises(RuntimeError, ncu.maximum.reduce, a)

    def test_failing_out_wrap(self):

        singleton = np.array([1.0])

        class Ok(np.ndarray):
            def __array_wrap__(self, obj):
                return singleton

        class Bad(np.ndarray):
            def __array_wrap__(self, obj):
                raise RuntimeError

        ok = np.empty(1).view(Ok)
        bad = np.empty(1).view(Bad)

        # double-free (segfault) of "ok" if "bad" raises an exception
        for i in range(10):
            assert_raises(RuntimeError, ncu.frexp, 1, ok, bad)

    def test_none_wrap(self):
        # Tests that issue #8507 is resolved. Previously, this would segfault

        class A(object):
            def __array__(self):
                return np.zeros(1)

            def __array_wrap__(self, arr, context=None):
                return None

        a = A()
        assert_equal(ncu.maximum(a, a), None)

    def test_default_prepare(self):

        class with_wrap(object):
            __array_priority__ = 10

            def __array__(self):
                return np.zeros(1)

            def __array_wrap__(self, arr, context):
                return arr

        a = with_wrap()
        x = ncu.minimum(a, a)
        assert_equal(x, np.zeros(1))
        assert_equal(type(x), np.ndarray)

    def test_prepare(self):

        class with_prepare(np.ndarray):
            __array_priority__ = 10

            def __array_prepare__(self, arr, context):
                # make sure we can return a new
                return np.array(arr).view(type=with_prepare)

        a = np.array(1).view(type=with_prepare)
        x = np.add(a, a)
        assert_equal(x, np.array(2))
        assert_equal(type(x), with_prepare)

    def test_prepare_out(self):

        class with_prepare(np.ndarray):
            __array_priority__ = 10

            def __array_prepare__(self, arr, context):
                return np.array(arr).view(type=with_prepare)

        a = np.array([1]).view(type=with_prepare)
        x = np.add(a, a, a)
        # Returned array is new, because of the strange
        # __array_prepare__ above
        assert_(not np.shares_memory(x, a))
        assert_equal(x, np.array([2]))
        assert_equal(type(x), with_prepare)

    def test_failing_prepare(self):

        class A(object):
            def __array__(self):
                return np.zeros(1)

            def __array_prepare__(self, arr, context=None):
                raise RuntimeError

        a = A()
        assert_raises(RuntimeError, ncu.maximum, a, a)

    def test_array_with_context(self):

        class A(object):
            def __array__(self, dtype=None, context=None):
                func, args, i = context
                self.func = func
                self.args = args
                self.i = i
                return np.zeros(1)

        class B(object):
            def __array__(self, dtype=None):
                return np.zeros(1, dtype)

        class C(object):
            def __array__(self):
                return np.zeros(1)

        a = A()
        ncu.maximum(np.zeros(1), a)
        assert_(a.func is ncu.maximum)
        assert_equal(a.args[0], 0)
        assert_(a.args[1] is a)
        assert_(a.i == 1)
        assert_equal(ncu.maximum(a, B()), 0)
        assert_equal(ncu.maximum(a, C()), 0)

    def test_ufunc_override(self):
        # check override works even with instance with high priority.
        class A(object):
            def __array_ufunc__(self, func, method, *inputs, **kwargs):
                return self, func, method, inputs, kwargs

        class MyNDArray(np.ndarray):
            __array_priority__ = 100

        a = A()
        b = np.array([1]).view(MyNDArray)
        res0 = np.multiply(a, b)
        res1 = np.multiply(b, b, out=a)

        # self
        assert_equal(res0[0], a)
        assert_equal(res1[0], a)
        assert_equal(res0[1], np.multiply)
        assert_equal(res1[1], np.multiply)
        assert_equal(res0[2], '__call__')
        assert_equal(res1[2], '__call__')
        assert_equal(res0[3], (a, b))
        assert_equal(res1[3], (b, b))
        assert_equal(res0[4], {})
        assert_equal(res1[4], {'out': (a,)})

    def test_ufunc_override_mro(self):

        # Some multi arg functions for testing.
        def tres_mul(a, b, c):
            return a * b * c

        def quatro_mul(a, b, c, d):
            return a * b * c * d

        # Make these into ufuncs.
        three_mul_ufunc = np.frompyfunc(tres_mul, 3, 1)
        four_mul_ufunc = np.frompyfunc(quatro_mul, 4, 1)

        class A(object):
            def __array_ufunc__(self, func, method, *inputs, **kwargs):
                return "A"

        class ASub(A):
            def __array_ufunc__(self, func, method, *inputs, **kwargs):
                return "ASub"

        class B(object):
            def __array_ufunc__(self, func, method, *inputs, **kwargs):
                return "B"

        class C(object):
            def __init__(self):
                self.count = 0

            def __array_ufunc__(self, func, method, *inputs, **kwargs):
                self.count += 1
                return NotImplemented

        class CSub(C):
            def __array_ufunc__(self, func, method, *inputs, **kwargs):
                self.count += 1
                return NotImplemented

        a = A()
        a_sub = ASub()
        b = B()
        c = C()

        # Standard
        res = np.multiply(a, a_sub)
        assert_equal(res, "ASub")
        res = np.multiply(a_sub, b)
        assert_equal(res, "ASub")

        # With 1 NotImplemented
        res = np.multiply(c, a)
        assert_equal(res, "A")
        assert_equal(c.count, 1)
        # Check our counter works, so we can trust tests below.
        res = np.multiply(c, a)
        assert_equal(c.count, 2)

        # Both NotImplemented.
        c = C()
        c_sub = CSub()
        assert_raises(TypeError, np.multiply, c, c_sub)
        assert_equal(c.count, 1)
        assert_equal(c_sub.count, 1)
        c.count = c_sub.count = 0
        assert_raises(TypeError, np.multiply, c_sub, c)
        assert_equal(c.count, 1)
        assert_equal(c_sub.count, 1)
        c.count = 0
        assert_raises(TypeError, np.multiply, c, c)
        assert_equal(c.count, 1)
        c.count = 0
        assert_raises(TypeError, np.multiply, 2, c)
        assert_equal(c.count, 1)

        # Ternary testing.
        assert_equal(three_mul_ufunc(a, 1, 2), "A")
        assert_equal(three_mul_ufunc(1, a, 2), "A")
        assert_equal(three_mul_ufunc(1, 2, a), "A")

        assert_equal(three_mul_ufunc(a, a, 6), "A")
        assert_equal(three_mul_ufunc(a, 2, a), "A")
        assert_equal(three_mul_ufunc(a, 2, b), "A")
        assert_equal(three_mul_ufunc(a, 2, a_sub), "ASub")
        assert_equal(three_mul_ufunc(a, a_sub, 3), "ASub")
        c.count = 0
        assert_equal(three_mul_ufunc(c, a_sub, 3), "ASub")
        assert_equal(c.count, 1)
        c.count = 0
        assert_equal(three_mul_ufunc(1, a_sub, c), "ASub")
        assert_equal(c.count, 0)

        c.count = 0
        assert_equal(three_mul_ufunc(a, b, c), "A")
        assert_equal(c.count, 0)
        c_sub.count = 0
        assert_equal(three_mul_ufunc(a, b, c_sub), "A")
        assert_equal(c_sub.count, 0)
        assert_equal(three_mul_ufunc(1, 2, b), "B")

        assert_raises(TypeError, three_mul_ufunc, 1, 2, c)
        assert_raises(TypeError, three_mul_ufunc, c_sub, 2, c)
        assert_raises(TypeError, three_mul_ufunc, c_sub, 2, 3)

        # Quaternary testing.
        assert_equal(four_mul_ufunc(a, 1, 2, 3), "A")
        assert_equal(four_mul_ufunc(1, a, 2, 3), "A")
        assert_equal(four_mul_ufunc(1, 1, a, 3), "A")
        assert_equal(four_mul_ufunc(1, 1, 2, a), "A")

        assert_equal(four_mul_ufunc(a, b, 2, 3), "A")
        assert_equal(four_mul_ufunc(1, a, 2, b), "A")
        assert_equal(four_mul_ufunc(b, 1, a, 3), "B")
        assert_equal(four_mul_ufunc(a_sub, 1, 2, a), "ASub")
        assert_equal(four_mul_ufunc(a, 1, 2, a_sub), "ASub")

        c = C()
        c_sub = CSub()
        assert_raises(TypeError, four_mul_ufunc, 1, 2, 3, c)
        assert_equal(c.count, 1)
        c.count = 0
        assert_raises(TypeError, four_mul_ufunc, 1, 2, c_sub, c)
        assert_equal(c_sub.count, 1)
        assert_equal(c.count, 1)
        c2 = C()
        c.count = c_sub.count = 0
        assert_raises(TypeError, four_mul_ufunc, 1, c, c_sub, c2)
        assert_equal(c_sub.count, 1)
        assert_equal(c.count, 1)
        assert_equal(c2.count, 0)
        c.count = c2.count = c_sub.count = 0
        assert_raises(TypeError, four_mul_ufunc, c2, c, c_sub, c)
        assert_equal(c_sub.count, 1)
        assert_equal(c.count, 0)
        assert_equal(c2.count, 1)

    def test_ufunc_override_methods(self):

        class A(object):
            def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
                return self, ufunc, method, inputs, kwargs

        # __call__
        a = A()
        res = np.multiply.__call__(1, a, foo='bar', answer=42)
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], '__call__')
        assert_equal(res[3], (1, a))
        assert_equal(res[4], {'foo': 'bar', 'answer': 42})

        # __call__, wrong args
        assert_raises(TypeError, np.multiply, a)
        assert_raises(TypeError, np.multiply, a, a, a, a)
        assert_raises(TypeError, np.multiply, a, a, sig='a', signature='a')
        assert_raises(TypeError, ncu_tests.inner1d, a, a, axis=0, axes=[0, 0])

        # reduce, positional args
        res = np.multiply.reduce(a, 'axis0', 'dtype0', 'out0', 'keep0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'reduce')
        assert_equal(res[3], (a,))
        assert_equal(res[4], {'dtype':'dtype0',
                              'out': ('out0',),
                              'keepdims': 'keep0',
                              'axis': 'axis0'})

        # reduce, kwargs
        res = np.multiply.reduce(a, axis='axis0', dtype='dtype0', out='out0',
                                 keepdims='keep0', initial='init0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'reduce')
        assert_equal(res[3], (a,))
        assert_equal(res[4], {'dtype':'dtype0',
                              'out': ('out0',),
                              'keepdims': 'keep0',
                              'axis': 'axis0',
                              'initial': 'init0'})

        # reduce, output equal to None removed, but not other explicit ones,
        # even if they are at their default value.
        res = np.multiply.reduce(a, 0, None, None, False)
        assert_equal(res[4], {'axis': 0, 'dtype': None, 'keepdims': False})
        res = np.multiply.reduce(a, out=None, axis=0, keepdims=True)
        assert_equal(res[4], {'axis': 0, 'keepdims': True})
        res = np.multiply.reduce(a, None, out=(None,), dtype=None)
        assert_equal(res[4], {'axis': None, 'dtype': None})
        res = np.multiply.reduce(a, 0, None, None, False, 2)
        assert_equal(res[4], {'axis': 0, 'dtype': None, 'keepdims': False, 'initial': 2})
        # np._NoValue ignored for initial.
        res = np.multiply.reduce(a, 0, None, None, False, np._NoValue)
        assert_equal(res[4], {'axis': 0, 'dtype': None, 'keepdims': False})
        # None kept for initial.
        res = np.multiply.reduce(a, 0, None, None, False, None)
        assert_equal(res[4], {'axis': 0, 'dtype': None, 'keepdims': False, 'initial': None})

        # reduce, wrong args
        assert_raises(ValueError, np.multiply.reduce, a, out=())
        assert_raises(ValueError, np.multiply.reduce, a, out=('out0', 'out1'))
        assert_raises(TypeError, np.multiply.reduce, a, 'axis0', axis='axis0')

        # accumulate, pos args
        res = np.multiply.accumulate(a, 'axis0', 'dtype0', 'out0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'accumulate')
        assert_equal(res[3], (a,))
        assert_equal(res[4], {'dtype':'dtype0',
                              'out': ('out0',),
                              'axis': 'axis0'})

        # accumulate, kwargs
        res = np.multiply.accumulate(a, axis='axis0', dtype='dtype0',
                                     out='out0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'accumulate')
        assert_equal(res[3], (a,))
        assert_equal(res[4], {'dtype':'dtype0',
                              'out': ('out0',),
                              'axis': 'axis0'})

        # accumulate, output equal to None removed.
        res = np.multiply.accumulate(a, 0, None, None)
        assert_equal(res[4], {'axis': 0, 'dtype': None})
        res = np.multiply.accumulate(a, out=None, axis=0, dtype='dtype1')
        assert_equal(res[4], {'axis': 0, 'dtype': 'dtype1'})
        res = np.multiply.accumulate(a, None, out=(None,), dtype=None)
        assert_equal(res[4], {'axis': None, 'dtype': None})

        # accumulate, wrong args
        assert_raises(ValueError, np.multiply.accumulate, a, out=())
        assert_raises(ValueError, np.multiply.accumulate, a,
                      out=('out0', 'out1'))
        assert_raises(TypeError, np.multiply.accumulate, a,
                      'axis0', axis='axis0')

        # reduceat, pos args
        res = np.multiply.reduceat(a, [4, 2], 'axis0', 'dtype0', 'out0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'reduceat')
        assert_equal(res[3], (a, [4, 2]))
        assert_equal(res[4], {'dtype':'dtype0',
                              'out': ('out0',),
                              'axis': 'axis0'})

        # reduceat, kwargs
        res = np.multiply.reduceat(a, [4, 2], axis='axis0', dtype='dtype0',
                                   out='out0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'reduceat')
        assert_equal(res[3], (a, [4, 2]))
        assert_equal(res[4], {'dtype':'dtype0',
                              'out': ('out0',),
                              'axis': 'axis0'})

        # reduceat, output equal to None removed.
        res = np.multiply.reduceat(a, [4, 2], 0, None, None)
        assert_equal(res[4], {'axis': 0, 'dtype': None})
        res = np.multiply.reduceat(a, [4, 2], axis=None, out=None, dtype='dt')
        assert_equal(res[4], {'axis': None, 'dtype': 'dt'})
        res = np.multiply.reduceat(a, [4, 2], None, None, out=(None,))
        assert_equal(res[4], {'axis': None, 'dtype': None})

        # reduceat, wrong args
        assert_raises(ValueError, np.multiply.reduce, a, [4, 2], out=())
        assert_raises(ValueError, np.multiply.reduce, a, [4, 2],
                      out=('out0', 'out1'))
        assert_raises(TypeError, np.multiply.reduce, a, [4, 2],
                      'axis0', axis='axis0')

        # outer
        res = np.multiply.outer(a, 42)
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'outer')
        assert_equal(res[3], (a, 42))
        assert_equal(res[4], {})

        # outer, wrong args
        assert_raises(TypeError, np.multiply.outer, a)
        assert_raises(TypeError, np.multiply.outer, a, a, a, a)
        assert_raises(TypeError, np.multiply.outer, a, a, sig='a', signature='a')

        # at
        res = np.multiply.at(a, [4, 2], 'b0')
        assert_equal(res[0], a)
        assert_equal(res[1], np.multiply)
        assert_equal(res[2], 'at')
        assert_equal(res[3], (a, [4, 2], 'b0'))

        # at, wrong args
        assert_raises(TypeError, np.multiply.at, a)
        assert_raises(TypeError, np.multiply.at, a, a, a, a)

    def test_ufunc_override_out(self):

        class A(object):
            def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
                return kwargs

        class B(object):
            def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
                return kwargs

        a = A()
        b = B()
        res0 = np.multiply(a, b, 'out_arg')
        res1 = np.multiply(a, b, out='out_arg')
        res2 = np.multiply(2, b, 'out_arg')
        res3 = np.multiply(3, b, out='out_arg')
        res4 = np.multiply(a, 4, 'out_arg')
        res5 = np.multiply(a, 5, out='out_arg')

        assert_equal(res0['out'][0], 'out_arg')
        assert_equal(res1['out'][0], 'out_arg')
        assert_equal(res2['out'][0], 'out_arg')
        assert_equal(res3['out'][0], 'out_arg')
        assert_equal(res4['out'][0], 'out_arg')
        assert_equal(res5['out'][0], 'out_arg')

        # ufuncs with multiple output modf and frexp.
        res6 = np.modf(a, 'out0', 'out1')
        res7 = np.frexp(a, 'out0', 'out1')
        assert_equal(res6['out'][0], 'out0')
        assert_equal(res6['out'][1], 'out1')
        assert_equal(res7['out'][0], 'out0')
        assert_equal(res7['out'][1], 'out1')

        # While we're at it, check that default output is never passed on.
        assert_(np.sin(a, None) == {})
        assert_(np.sin(a, out=None) == {})
        assert_(np.sin(a, out=(None,)) == {})
        assert_(np.modf(a, None) == {})
        assert_(np.modf(a, None, None) == {})
        assert_(np.modf(a, out=(None, None)) == {})
        with warnings.catch_warnings(record=True) as w:
            warnings.filterwarnings('always', '', DeprecationWarning)
            assert_(np.modf(a, out=None) == {})
            assert_(w[0].category is DeprecationWarning)

        # don't give positional and output argument, or too many arguments.
        # wrong number of arguments in the tuple is an error too.
        assert_raises(TypeError, np.multiply, a, b, 'one', out='two')
        assert_raises(TypeError, np.multiply, a, b, 'one', 'two')
        assert_raises(ValueError, np.multiply, a, b, out=('one', 'two'))
        assert_raises(ValueError, np.multiply, a, out=())
        assert_raises(TypeError, np.modf, a, 'one', out=('two', 'three'))
        assert_raises(TypeError, np.modf, a, 'one', 'two', 'three')
        assert_raises(ValueError, np.modf, a, out=('one', 'two', 'three'))
        assert_raises(ValueError, np.modf, a, out=('one',))

    def test_ufunc_override_exception(self):

        class A(object):
            def __array_ufunc__(self, *a, **kwargs):
                raise ValueError("oops")

        a = A()
        assert_raises(ValueError, np.negative, 1, out=a)
        assert_raises(ValueError, np.negative, a)
        assert_raises(ValueError, np.divide, 1., a)

    def test_ufunc_override_not_implemented(self):

        class A(object):
            def __array_ufunc__(self, *args, **kwargs):
                return NotImplemented

        msg = ("operand type(s) all returned NotImplemented from "
               "__array_ufunc__(<ufunc 'negative'>, '__call__', <*>): 'A'")
        with assert_raises_regex(TypeError, fnmatch.translate(msg)):
            np.negative(A())

        msg = ("operand type(s) all returned NotImplemented from "
               "__array_ufunc__(<ufunc 'add'>, '__call__', <*>, <object *>, "
               "out=(1,)): 'A', 'object', 'int'")
        with assert_raises_regex(TypeError, fnmatch.translate(msg)):
            np.add(A(), object(), out=1)

    def test_ufunc_override_disabled(self):

        class OptOut(object):
            __array_ufunc__ = None

        opt_out = OptOut()

        # ufuncs always raise
        msg = "operand 'OptOut' does not support ufuncs"
        with assert_raises_regex(TypeError, msg):
            np.add(opt_out, 1)
        with assert_raises_regex(TypeError, msg):
            np.add(1, opt_out)
        with assert_raises_regex(TypeError, msg):
            np.negative(opt_out)

        # opt-outs still hold even when other arguments have pathological
        # __array_ufunc__ implementations

        class GreedyArray(object):
            def __array_ufunc__(self, *args, **kwargs):
                return self

        greedy = GreedyArray()
        assert_(np.negative(greedy) is greedy)
        with assert_raises_regex(TypeError, msg):
            np.add(greedy, opt_out)
        with assert_raises_regex(TypeError, msg):
            np.add(greedy, 1, out=opt_out)

    def test_gufunc_override(self):
        # gufunc are just ufunc instances, but follow a different path,
        # so check __array_ufunc__ overrides them properly.
        class A(object):
            def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
                return self, ufunc, method, inputs, kwargs

        inner1d = ncu_tests.inner1d
        a = A()
        res = inner1d(a, a)
        assert_equal(res[0], a)
        assert_equal(res[1], inner1d)
        assert_equal(res[2], '__call__')
        assert_equal(res[3], (a, a))
        assert_equal(res[4], {})

        res = inner1d(1, 1, out=a)
        assert_equal(res[0], a)
        assert_equal(res[1], inner1d)
        assert_equal(res[2], '__call__')
        assert_equal(res[3], (1, 1))
        assert_equal(res[4], {'out': (a,)})

        # wrong number of arguments in the tuple is an error too.
        assert_raises(TypeError, inner1d, a, out='two')
        assert_raises(TypeError, inner1d, a, a, 'one', out='two')
        assert_raises(TypeError, inner1d, a, a, 'one', 'two')
        assert_raises(ValueError, inner1d, a, a, out=('one', 'two'))
        assert_raises(ValueError, inner1d, a, a, out=())

    def test_ufunc_override_with_super(self):
        # NOTE: this class is given as an example in doc/subclassing.py;
        # if you make any changes here, do update it there too.
        class A(np.ndarray):
            def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
                args = []
                in_no = []
                for i, input_ in enumerate(inputs):
                    if isinstance(input_, A):
                        in_no.append(i)
                        args.append(input_.view(np.ndarray))
                    else:
                        args.append(input_)

                outputs = kwargs.pop('out', None)
                out_no = []
                if outputs:
                    out_args = []
                    for j, output in enumerate(outputs):
                        if isinstance(output, A):
                            out_no.append(j)
                            out_args.append(output.view(np.ndarray))
                        else:
                            out_args.append(output)
                    kwargs['out'] = tuple(out_args)
                else:
                    outputs = (None,) * ufunc.nout

                info = {}
                if in_no:
                    info['inputs'] = in_no
                if out_no:
                    info['outputs'] = out_no

                results = super(A, self).__array_ufunc__(ufunc, method,
                                                         *args, **kwargs)
                if results is NotImplemented:
                    return NotImplemented

                if method == 'at':
                    if isinstance(inputs[0], A):
                        inputs[0].info = info
                    return

                if ufunc.nout == 1:
                    results = (results,)

                results = tuple((np.asarray(result).view(A)
                                 if output is None else output)
                                for result, output in zip(results, outputs))
                if results and isinstance(results[0], A):
                    results[0].info = info

                return results[0] if len(results) == 1 else results

        class B(object):
            def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
                if any(isinstance(input_, A) for input_ in inputs):
                    return "A!"
                else:
                    return NotImplemented

        d = np.arange(5.)
        # 1 input, 1 output
        a = np.arange(5.).view(A)
        b = np.sin(a)
        check = np.sin(d)
        assert_(np.all(check == b))
        assert_equal(b.info, {'inputs': [0]})
        b = np.sin(d, out=(a,))
        assert_(np.all(check == b))
        assert_equal(b.info, {'outputs': [0]})
        assert_(b is a)
        a = np.arange(5.).view(A)
        b = np.sin(a, out=a)
        assert_(np.all(check == b))
        assert_equal(b.info, {'inputs': [0], 'outputs': [0]})

        # 1 input, 2 outputs
        a = np.arange(5.).view(A)
        b1, b2 = np.modf(a)
        assert_equal(b1.info, {'inputs': [0]})
        b1, b2 = np.modf(d, out=(None, a))
        assert_(b2 is a)
        assert_equal(b1.info, {'outputs': [1]})
        a = np.arange(5.).view(A)
        b = np.arange(5.).view(A)
        c1, c2 = np.modf(a, out=(a, b))
        assert_(c1 is a)
        assert_(c2 is b)
        assert_equal(c1.info, {'inputs': [0], 'outputs': [0, 1]})

        # 2 input, 1 output
        a = np.arange(5.).view(A)
        b = np.arange(5.).view(A)
        c = np.add(a, b, out=a)
        assert_(c is a)
        assert_equal(c.info, {'inputs': [0, 1], 'outputs': [0]})
        # some tests with a non-ndarray subclass
        a = np.arange(5.)
        b = B()
        assert_(a.__array_ufunc__(np.add, '__call__', a, b) is NotImplemented)
        assert_(b.__array_ufunc__(np.add, '__call__', a, b) is NotImplemented)
        assert_raises(TypeError, np.add, a, b)
        a = a.view(A)
        assert_(a.__array_ufunc__(np.add, '__call__', a, b) is NotImplemented)
        assert_(b.__array_ufunc__(np.add, '__call__', a, b) == "A!")
        assert_(np.add(a, b) == "A!")
        # regression check for gh-9102 -- tests ufunc.reduce implicitly.
        d = np.array([[1, 2, 3], [1, 2, 3]])
        a = d.view(A)
        c = a.any()
        check = d.any()
        assert_equal(c, check)
        assert_(c.info, {'inputs': [0]})
        c = a.max()
        check = d.max()
        assert_equal(c, check)
        assert_(c.info, {'inputs': [0]})
        b = np.array(0).view(A)
        c = a.max(out=b)
        assert_equal(c, check)
        assert_(c is b)
        assert_(c.info, {'inputs': [0], 'outputs': [0]})
        check = a.max(axis=0)
        b = np.zeros_like(check).view(A)
        c = a.max(axis=0, out=b)
        assert_equal(c, check)
        assert_(c is b)
        assert_(c.info, {'inputs': [0], 'outputs': [0]})
        # simple explicit tests of reduce, accumulate, reduceat
        check = np.add.reduce(d, axis=1)
        c = np.add.reduce(a, axis=1)
        assert_equal(c, check)
        assert_(c.info, {'inputs': [0]})
        b = np.zeros_like(c)
        c = np.add.reduce(a, 1, None, b)
        assert_equal(c, check)
        assert_(c is b)
        assert_(c.info, {'inputs': [0], 'outputs': [0]})
        check = np.add.accumulate(d, axis=0)
        c = np.add.accumulate(a, axis=0)
        assert_equal(c, check)
        assert_(c.info, {'inputs': [0]})
        b = np.zeros_like(c)
        c = np.add.accumulate(a, 0, None, b)
        assert_equal(c, check)
        assert_(c is b)
        assert_(c.info, {'inputs': [0], 'outputs': [0]})
        indices = [0, 2, 1]
        check = np.add.reduceat(d, indices, axis=1)
        c = np.add.reduceat(a, indices, axis=1)
        assert_equal(c, check)
        assert_(c.info, {'inputs': [0]})
        b = np.zeros_like(c)
        c = np.add.reduceat(a, indices, 1, None, b)
        assert_equal(c, check)
        assert_(c is b)
        assert_(c.info, {'inputs': [0], 'outputs': [0]})
        # and a few tests for at
        d = np.array([[1, 2, 3], [1, 2, 3]])
        check = d.copy()
        a = d.copy().view(A)
        np.add.at(check, ([0, 1], [0, 2]), 1.)
        np.add.at(a, ([0, 1], [0, 2]), 1.)
        assert_equal(a, check)
        assert_(a.info, {'inputs': [0]})
        b = np.array(1.).view(A)
        a = d.copy().view(A)
        np.add.at(a, ([0, 1], [0, 2]), b)
        assert_equal(a, check)
        assert_(a.info, {'inputs': [0, 2]})


class TestChoose(object):
    def test_mixed(self):
        c = np.array([True, True])
        a = np.array([True, True])
        assert_equal(np.choose(c, (a, 1)), np.array([1, 1]))


class TestRationalFunctions(object):
    def test_lcm(self):
        self._test_lcm_inner(np.int16)
        self._test_lcm_inner(np.uint16)

    def test_lcm_object(self):
        self._test_lcm_inner(np.object_)

    def test_gcd(self):
        self._test_gcd_inner(np.int16)
        self._test_lcm_inner(np.uint16)

    def test_gcd_object(self):
        self._test_gcd_inner(np.object_)

    def _test_lcm_inner(self, dtype):
        # basic use
        a = np.array([12, 120], dtype=dtype)
        b = np.array([20, 200], dtype=dtype)
        assert_equal(np.lcm(a, b), [60, 600])

        if not issubclass(dtype, np.unsignedinteger):
            # negatives are ignored
            a = np.array([12, -12,  12, -12], dtype=dtype)
            b = np.array([20,  20, -20, -20], dtype=dtype)
            assert_equal(np.lcm(a, b), [60]*4)

        # reduce
        a = np.array([3, 12, 20], dtype=dtype)
        assert_equal(np.lcm.reduce([3, 12, 20]), 60)

        # broadcasting, and a test including 0
        a = np.arange(6).astype(dtype)
        b = 20
        assert_equal(np.lcm(a, b), [0, 20, 20, 60, 20, 20])

    def _test_gcd_inner(self, dtype):
        # basic use
        a = np.array([12, 120], dtype=dtype)
        b = np.array([20, 200], dtype=dtype)
        assert_equal(np.gcd(a, b), [4, 40])

        if not issubclass(dtype, np.unsignedinteger):
            # negatives are ignored
            a = np.array([12, -12,  12, -12], dtype=dtype)
            b = np.array([20,  20, -20, -20], dtype=dtype)
            assert_equal(np.gcd(a, b), [4]*4)

        # reduce
        a = np.array([15, 25, 35], dtype=dtype)
        assert_equal(np.gcd.reduce(a), 5)

        # broadcasting, and a test including 0
        a = np.arange(6).astype(dtype)
        b = 20
        assert_equal(np.gcd(a, b), [20,  1,  2,  1,  4,  5])

    def test_lcm_overflow(self):
        # verify that we don't overflow when a*b does overflow
        big = np.int32(np.iinfo(np.int32).max // 11)
        a = 2*big
        b = 5*big
        assert_equal(np.lcm(a, b), 10*big)

    def test_gcd_overflow(self):
        for dtype in (np.int32, np.int64):
            # verify that we don't overflow when taking abs(x)
            # not relevant for lcm, where the result is unrepresentable anyway
            a = dtype(np.iinfo(dtype).min)  # negative power of two
            q = -(a // 4)
            assert_equal(np.gcd(a,  q*3), q)
            assert_equal(np.gcd(a, -q*3), q)

    def test_decimal(self):
        from decimal import Decimal
        a = np.array([1,  1, -1, -1]) * Decimal('0.20')
        b = np.array([1, -1,  1, -1]) * Decimal('0.12')

        assert_equal(np.gcd(a, b), 4*[Decimal('0.04')])
        assert_equal(np.lcm(a, b), 4*[Decimal('0.60')])

    def test_float(self):
        # not well-defined on float due to rounding errors
        assert_raises(TypeError, np.gcd, 0.3, 0.4)
        assert_raises(TypeError, np.lcm, 0.3, 0.4)

    def test_builtin_long(self):
        # sanity check that array coercion is alright for builtin longs
        assert_equal(np.array(2**200).item(), 2**200)

        # expressed as prime factors
        a = np.array(2**100 * 3**5)
        b = np.array([2**100 * 5**7, 2**50 * 3**10])
        assert_equal(np.gcd(a, b), [2**100,               2**50 * 3**5])
        assert_equal(np.lcm(a, b), [2**100 * 3**5 * 5**7, 2**100 * 3**10])

        assert_equal(np.gcd(2**100, 3**100), 1)


class TestComplexFunctions(object):
    funcs = [np.arcsin,  np.arccos,  np.arctan, np.arcsinh, np.arccosh,
             np.arctanh, np.sin,     np.cos,    np.tan,     np.exp,
             np.exp2,    np.log,     np.sqrt,   np.log10,   np.log2,
             np.log1p]

    def test_it(self):
        for f in self.funcs:
            if f is np.arccosh:
                x = 1.5
            else:
                x = .5
            fr = f(x)
            fz = f(complex(x))
            assert_almost_equal(fz.real, fr, err_msg='real part %s' % f)
            assert_almost_equal(fz.imag, 0., err_msg='imag part %s' % f)

    def test_precisions_consistent(self):
        z = 1 + 1j
        for f in self.funcs:
            fcf = f(np.csingle(z))
            fcd = f(np.cdouble(z))
            fcl = f(np.clongdouble(z))
            assert_almost_equal(fcf, fcd, decimal=6, err_msg='fch-fcd %s' % f)
            assert_almost_equal(fcl, fcd, decimal=15, err_msg='fch-fcl %s' % f)

    def test_branch_cuts(self):
        # check branch cuts and continuity on them
        _check_branch_cut(np.log,   -0.5, 1j, 1, -1, True)
        _check_branch_cut(np.log2,  -0.5, 1j, 1, -1, True)
        _check_branch_cut(np.log10, -0.5, 1j, 1, -1, True)
        _check_branch_cut(np.log1p, -1.5, 1j, 1, -1, True)
        _check_branch_cut(np.sqrt,  -0.5, 1j, 1, -1, True)

        _check_branch_cut(np.arcsin, [ -2, 2],   [1j, 1j], 1, -1, True)
        _check_branch_cut(np.arccos, [ -2, 2],   [1j, 1j], 1, -1, True)
        _check_branch_cut(np.arctan, [0-2j, 2j],  [1,  1], -1, 1, True)

        _check_branch_cut(np.arcsinh, [0-2j,  2j], [1,   1], -1, 1, True)
        _check_branch_cut(np.arccosh, [ -1, 0.5], [1j,  1j], 1, -1, True)
        _check_branch_cut(np.arctanh, [ -2,   2], [1j, 1j], 1, -1, True)

        # check against bogus branch cuts: assert continuity between quadrants
        _check_branch_cut(np.arcsin, [0-2j, 2j], [ 1,  1], 1, 1)
        _check_branch_cut(np.arccos, [0-2j, 2j], [ 1,  1], 1, 1)
        _check_branch_cut(np.arctan, [ -2,  2], [1j, 1j], 1, 1)

        _check_branch_cut(np.arcsinh, [ -2,  2, 0], [1j, 1j, 1], 1, 1)
        _check_branch_cut(np.arccosh, [0-2j, 2j, 2], [1,  1,  1j], 1, 1)
        _check_branch_cut(np.arctanh, [0-2j, 2j, 0], [1,  1,  1j], 1, 1)

    def test_branch_cuts_complex64(self):
        # check branch cuts and continuity on them
        _check_branch_cut(np.log,   -0.5, 1j, 1, -1, True, np.complex64)
        _check_branch_cut(np.log2,  -0.5, 1j, 1, -1, True, np.complex64)
        _check_branch_cut(np.log10, -0.5, 1j, 1, -1, True, np.complex64)
        _check_branch_cut(np.log1p, -1.5, 1j, 1, -1, True, np.complex64)
        _check_branch_cut(np.sqrt,  -0.5, 1j, 1, -1, True, np.complex64)

        _check_branch_cut(np.arcsin, [ -2, 2],   [1j, 1j], 1, -1, True, np.complex64)
        _check_branch_cut(np.arccos, [ -2, 2],   [1j, 1j], 1, -1, True, np.complex64)
        _check_branch_cut(np.arctan, [0-2j, 2j],  [1,  1], -1, 1, True, np.complex64)

        _check_branch_cut(np.arcsinh, [0-2j,  2j], [1,   1], -1, 1, True, np.complex64)
        _check_branch_cut(np.arccosh, [ -1, 0.5], [1j,  1j], 1, -1, True, np.complex64)
        _check_branch_cut(np.arctanh, [ -2,   2], [1j, 1j], 1, -1, True, np.complex64)

        # check against bogus branch cuts: assert continuity between quadrants
        _check_branch_cut(np.arcsin, [0-2j, 2j], [ 1,  1], 1, 1, False, np.complex64)
        _check_branch_cut(np.arccos, [0-2j, 2j], [ 1,  1], 1, 1, False, np.complex64)
        _check_branch_cut(np.arctan, [ -2,  2], [1j, 1j], 1, 1, False, np.complex64)

        _check_branch_cut(np.arcsinh, [ -2,  2, 0], [1j, 1j, 1], 1, 1, False, np.complex64)
        _check_branch_cut(np.arccosh, [0-2j, 2j, 2], [1,  1,  1j], 1, 1, False, np.complex64)
        _check_branch_cut(np.arctanh, [0-2j, 2j, 0], [1,  1,  1j], 1, 1, False, np.complex64)

    def test_against_cmath(self):
        import cmath

        points = [-1-1j, -1+1j, +1-1j, +1+1j]
        name_map = {'arcsin': 'asin', 'arccos': 'acos', 'arctan': 'atan',
                    'arcsinh': 'asinh', 'arccosh': 'acosh', 'arctanh': 'atanh'}
        atol = 4*np.finfo(complex).eps
        for func in self.funcs:
            fname = func.__name__.split('.')[-1]
            cname = name_map.get(fname, fname)
            try:
                cfunc = getattr(cmath, cname)
            except AttributeError:
                continue
            for p in points:
                a = complex(func(np.complex_(p)))
                b = cfunc(p)
                assert_(abs(a - b) < atol, "%s %s: %s; cmath: %s" % (fname, p, a, b))

    @pytest.mark.parametrize('dtype', [np.complex64, np.complex_, np.longcomplex])
    def test_loss_of_precision(self, dtype):
        """Check loss of precision in complex arc* functions"""

        # Check against known-good functions

        info = np.finfo(dtype)
        real_dtype = dtype(0.).real.dtype
        eps = info.eps

        def check(x, rtol):
            x = x.astype(real_dtype)

            z = x.astype(dtype)
            d = np.absolute(np.arcsinh(x)/np.arcsinh(z).real - 1)
            assert_(np.all(d < rtol), (np.argmax(d), x[np.argmax(d)], d.max(),
                                      'arcsinh'))

            z = (1j*x).astype(dtype)
            d = np.absolute(np.arcsinh(x)/np.arcsin(z).imag - 1)
            assert_(np.all(d < rtol), (np.argmax(d), x[np.argmax(d)], d.max(),
                                      'arcsin'))

            z = x.astype(dtype)
            d = np.absolute(np.arctanh(x)/np.arctanh(z).real - 1)
            assert_(np.all(d < rtol), (np.argmax(d), x[np.argmax(d)], d.max(),
                                      'arctanh'))

            z = (1j*x).astype(dtype)
            d = np.absolute(np.arctanh(x)/np.arctan(z).imag - 1)
            assert_(np.all(d < rtol), (np.argmax(d), x[np.argmax(d)], d.max(),
                                      'arctan'))

        # The switchover was chosen as 1e-3; hence there can be up to
        # ~eps/1e-3 of relative cancellation error before it

        x_series = np.logspace(-20, -3.001, 200)
        x_basic = np.logspace(-2.999, 0, 10, endpoint=False)

        if dtype is np.longcomplex:
            # It's not guaranteed that the system-provided arc functions
            # are accurate down to a few epsilons. (Eg. on Linux 64-bit)
            # So, give more leeway for long complex tests here:
            # Can use 2.1 for > Ubuntu LTS Trusty (2014), glibc = 2.19.
            check(x_series, 50.0*eps)
        else:
            check(x_series, 2.1*eps)
        check(x_basic, 2.0*eps/1e-3)

        # Check a few points

        z = np.array([1e-5*(1+1j)], dtype=dtype)
        p = 9.999999999333333333e-6 + 1.000000000066666666e-5j
        d = np.absolute(1-np.arctanh(z)/p)
        assert_(np.all(d < 1e-15))

        p = 1.0000000000333333333e-5 + 9.999999999666666667e-6j
        d = np.absolute(1-np.arcsinh(z)/p)
        assert_(np.all(d < 1e-15))

        p = 9.999999999333333333e-6j + 1.000000000066666666e-5
        d = np.absolute(1-np.arctan(z)/p)
        assert_(np.all(d < 1e-15))

        p = 1.0000000000333333333e-5j + 9.999999999666666667e-6
        d = np.absolute(1-np.arcsin(z)/p)
        assert_(np.all(d < 1e-15))

        # Check continuity across switchover points

        def check(func, z0, d=1):
            z0 = np.asarray(z0, dtype=dtype)
            zp = z0 + abs(z0) * d * eps * 2
            zm = z0 - abs(z0) * d * eps * 2
            assert_(np.all(zp != zm), (zp, zm))

            # NB: the cancellation error at the switchover is at least eps
            good = (abs(func(zp) - func(zm)) < 2*eps)
            assert_(np.all(good), (func, z0[~good]))

        for func in (np.arcsinh, np.arcsinh, np.arcsin, np.arctanh, np.arctan):
            pts = [rp+1j*ip for rp in (-1e-3, 0, 1e-3) for ip in(-1e-3, 0, 1e-3)
                   if rp != 0 or ip != 0]
            check(func, pts, 1)
            check(func, pts, 1j)
            check(func, pts, 1+1j)


class TestAttributes(object):
    def test_attributes(self):
        add = ncu.add
        assert_equal(add.__name__, 'add')
        assert_(add.ntypes >= 18)  # don't fail if types added
        assert_('ii->i' in add.types)
        assert_equal(add.nin, 2)
        assert_equal(add.nout, 1)
        assert_equal(add.identity, 0)

    def test_doc(self):
        # don't bother checking the long list of kwargs, which are likely to
        # change
        assert_(ncu.add.__doc__.startswith(
            "add(x1, x2, /, out=None, *, where=True"))
        assert_(ncu.frexp.__doc__.startswith(
            "frexp(x[, out1, out2], / [, out=(None, None)], *, where=True"))


class TestSubclass(object):

    def test_subclass_op(self):

        class simple(np.ndarray):
            def __new__(subtype, shape):
                self = np.ndarray.__new__(subtype, shape, dtype=object)
                self.fill(0)
                return self

        a = simple((3, 4))
        assert_equal(a+a, a)

def _check_branch_cut(f, x0, dx, re_sign=1, im_sign=-1, sig_zero_ok=False,
                      dtype=complex):
    """
    Check for a branch cut in a function.

    Assert that `x0` lies on a branch cut of function `f` and `f` is
    continuous from the direction `dx`.

    Parameters
    ----------
    f : func
        Function to check
    x0 : array-like
        Point on branch cut
    dx : array-like
        Direction to check continuity in
    re_sign, im_sign : {1, -1}
        Change of sign of the real or imaginary part expected
    sig_zero_ok : bool
        Whether to check if the branch cut respects signed zero (if applicable)
    dtype : dtype
        Dtype to check (should be complex)

    """
    x0 = np.atleast_1d(x0).astype(dtype)
    dx = np.atleast_1d(dx).astype(dtype)

    if np.dtype(dtype).char == 'F':
        scale = np.finfo(dtype).eps * 1e2
        atol = np.float32(1e-2)
    else:
        scale = np.finfo(dtype).eps * 1e3
        atol = 1e-4

    y0 = f(x0)
    yp = f(x0 + dx*scale*np.absolute(x0)/np.absolute(dx))
    ym = f(x0 - dx*scale*np.absolute(x0)/np.absolute(dx))

    assert_(np.all(np.absolute(y0.real - yp.real) < atol), (y0, yp))
    assert_(np.all(np.absolute(y0.imag - yp.imag) < atol), (y0, yp))
    assert_(np.all(np.absolute(y0.real - ym.real*re_sign) < atol), (y0, ym))
    assert_(np.all(np.absolute(y0.imag - ym.imag*im_sign) < atol), (y0, ym))

    if sig_zero_ok:
        # check that signed zeros also work as a displacement
        jr = (x0.real == 0) & (dx.real != 0)
        ji = (x0.imag == 0) & (dx.imag != 0)
        if np.any(jr):
            x = x0[jr]
            x.real = np.NZERO
            ym = f(x)
            assert_(np.all(np.absolute(y0[jr].real - ym.real*re_sign) < atol), (y0[jr], ym))
            assert_(np.all(np.absolute(y0[jr].imag - ym.imag*im_sign) < atol), (y0[jr], ym))

        if np.any(ji):
            x = x0[ji]
            x.imag = np.NZERO
            ym = f(x)
            assert_(np.all(np.absolute(y0[ji].real - ym.real*re_sign) < atol), (y0[ji], ym))
            assert_(np.all(np.absolute(y0[ji].imag - ym.imag*im_sign) < atol), (y0[ji], ym))

def test_copysign():
    assert_(np.copysign(1, -1) == -1)
    with np.errstate(divide="ignore"):
        assert_(1 / np.copysign(0, -1) < 0)
        assert_(1 / np.copysign(0, 1) > 0)
    assert_(np.signbit(np.copysign(np.nan, -1)))
    assert_(not np.signbit(np.copysign(np.nan, 1)))

def _test_nextafter(t):
    one = t(1)
    two = t(2)
    zero = t(0)
    eps = np.finfo(t).eps
    assert_(np.nextafter(one, two) - one == eps)
    assert_(np.nextafter(one, zero) - one < 0)
    assert_(np.isnan(np.nextafter(np.nan, one)))
    assert_(np.isnan(np.nextafter(one, np.nan)))
    assert_(np.nextafter(one, one) == one)

def test_nextafter():
    return _test_nextafter(np.float64)


def test_nextafterf():
    return _test_nextafter(np.float32)


@pytest.mark.skipif(np.finfo(np.double) == np.finfo(np.longdouble),
                    reason="long double is same as double")
@pytest.mark.xfail(condition=platform.machine().startswith("ppc64"),
                    reason="IBM double double")
def test_nextafterl():
    return _test_nextafter(np.longdouble)


def test_nextafter_0():
    for t, direction in itertools.product(np.sctypes['float'], (1, -1)):
        tiny = np.finfo(t).tiny
        assert_(0. < direction * np.nextafter(t(0), t(direction)) < tiny)
        assert_equal(np.nextafter(t(0), t(direction)) / t(2.1), direction * 0.0)

def _test_spacing(t):
    one = t(1)
    eps = np.finfo(t).eps
    nan = t(np.nan)
    inf = t(np.inf)
    with np.errstate(invalid='ignore'):
        assert_(np.spacing(one) == eps)
        assert_(np.isnan(np.spacing(nan)))
        assert_(np.isnan(np.spacing(inf)))
        assert_(np.isnan(np.spacing(-inf)))
        assert_(np.spacing(t(1e30)) != 0)

def test_spacing():
    return _test_spacing(np.float64)

def test_spacingf():
    return _test_spacing(np.float32)


@pytest.mark.skipif(np.finfo(np.double) == np.finfo(np.longdouble),
                    reason="long double is same as double")
@pytest.mark.xfail(condition=platform.machine().startswith("ppc64"),
                    reason="IBM double double")
def test_spacingl():
    return _test_spacing(np.longdouble)

def test_spacing_gfortran():
    # Reference from this fortran file, built with gfortran 4.3.3 on linux
    # 32bits:
    #       PROGRAM test_spacing
    #        INTEGER, PARAMETER :: SGL = SELECTED_REAL_KIND(p=6, r=37)
    #        INTEGER, PARAMETER :: DBL = SELECTED_REAL_KIND(p=13, r=200)
    #
    #        WRITE(*,*) spacing(0.00001_DBL)
    #        WRITE(*,*) spacing(1.0_DBL)
    #        WRITE(*,*) spacing(1000._DBL)
    #        WRITE(*,*) spacing(10500._DBL)
    #
    #        WRITE(*,*) spacing(0.00001_SGL)
    #        WRITE(*,*) spacing(1.0_SGL)
    #        WRITE(*,*) spacing(1000._SGL)
    #        WRITE(*,*) spacing(10500._SGL)
    #       END PROGRAM
    ref = {np.float64: [1.69406589450860068E-021,
                        2.22044604925031308E-016,
                        1.13686837721616030E-013,
                        1.81898940354585648E-012],
           np.float32: [9.09494702E-13,
                        1.19209290E-07,
                        6.10351563E-05,
                        9.76562500E-04]}

    for dt, dec_ in zip([np.float32, np.float64], (10, 20)):
        x = np.array([1e-5, 1, 1000, 10500], dtype=dt)
        assert_array_almost_equal(np.spacing(x), ref[dt], decimal=dec_)

def test_nextafter_vs_spacing():
    # XXX: spacing does not handle long double yet
    for t in [np.float32, np.float64]:
        for _f in [1, 1e-5, 1000]:
            f = t(_f)
            f1 = t(_f + 1)
            assert_(np.nextafter(f, f1) - f == np.spacing(f))

def test_pos_nan():
    """Check np.nan is a positive nan."""
    assert_(np.signbit(np.nan) == 0)

def test_reduceat():
    """Test bug in reduceat when structured arrays are not copied."""
    db = np.dtype([('name', 'S11'), ('time', np.int64), ('value', np.float32)])
    a = np.empty([100], dtype=db)
    a['name'] = 'Simple'
    a['time'] = 10
    a['value'] = 100
    indx = [0, 7, 15, 25]

    h2 = []
    val1 = indx[0]
    for val2 in indx[1:]:
        h2.append(np.add.reduce(a['value'][val1:val2]))
        val1 = val2
    h2.append(np.add.reduce(a['value'][val1:]))
    h2 = np.array(h2)

    # test buffered -- this should work
    h1 = np.add.reduceat(a['value'], indx)
    assert_array_almost_equal(h1, h2)

    # This is when the error occurs.
    # test no buffer
    np.setbufsize(32)
    h1 = np.add.reduceat(a['value'], indx)
    np.setbufsize(np.UFUNC_BUFSIZE_DEFAULT)
    assert_array_almost_equal(h1, h2)

def test_reduceat_empty():
    """Reduceat should work with empty arrays"""
    indices = np.array([], 'i4')
    x = np.array([], 'f8')
    result = np.add.reduceat(x, indices)
    assert_equal(result.dtype, x.dtype)
    assert_equal(result.shape, (0,))
    # Another case with a slightly different zero-sized shape
    x = np.ones((5, 2))
    result = np.add.reduceat(x, [], axis=0)
    assert_equal(result.dtype, x.dtype)
    assert_equal(result.shape, (0, 2))
    result = np.add.reduceat(x, [], axis=1)
    assert_equal(result.dtype, x.dtype)
    assert_equal(result.shape, (5, 0))

def test_complex_nan_comparisons():
    nans = [complex(np.nan, 0), complex(0, np.nan), complex(np.nan, np.nan)]
    fins = [complex(1, 0), complex(-1, 0), complex(0, 1), complex(0, -1),
            complex(1, 1), complex(-1, -1), complex(0, 0)]

    with np.errstate(invalid='ignore'):
        for x in nans + fins:
            x = np.array([x])
            for y in nans + fins:
                y = np.array([y])

                if np.isfinite(x) and np.isfinite(y):
                    continue

                assert_equal(x < y, False, err_msg="%r < %r" % (x, y))
                assert_equal(x > y, False, err_msg="%r > %r" % (x, y))
                assert_equal(x <= y, False, err_msg="%r <= %r" % (x, y))
                assert_equal(x >= y, False, err_msg="%r >= %r" % (x, y))
                assert_equal(x == y, False, err_msg="%r == %r" % (x, y))


def test_rint_big_int():
    # np.rint bug for large integer values on Windows 32-bit and MKL
    # https://github.com/numpy/numpy/issues/6685
    val = 4607998452777363968
    # This is exactly representable in floating point
    assert_equal(val, int(float(val)))
    # Rint should not change the value
    assert_equal(val, np.rint(val))


def test_signaling_nan_exceptions():
    with assert_no_warnings():
        a = np.ndarray(shape=(), dtype='float32', buffer=b'\x00\xe0\xbf\xff')
        np.isnan(a)
