python类signbit()的实例源码

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)))

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

def test_nans_infs(self):
        with np.errstate(all='ignore'):
            # Check some of the ufuncs
            assert_equal(np.isnan(self.all_f16), np.isnan(self.all_f32))
            assert_equal(np.isinf(self.all_f16), np.isinf(self.all_f32))
            assert_equal(np.isfinite(self.all_f16), np.isfinite(self.all_f32))
            assert_equal(np.signbit(self.all_f16), np.signbit(self.all_f32))
            assert_equal(np.spacing(float16(65504)), np.inf)

            # Check comparisons of all values with NaN
            nan = float16(np.nan)

            assert_(not (self.all_f16 == nan).any())
            assert_(not (nan == self.all_f16).any())

            assert_((self.all_f16 != nan).all())
            assert_((nan != self.all_f16).all())

            assert_(not (self.all_f16 < nan).any())
            assert_(not (nan < self.all_f16).any())

            assert_(not (self.all_f16 <= nan).any())
            assert_(not (nan <= self.all_f16).any())

            assert_(not (self.all_f16 > nan).any())
            assert_(not (nan > self.all_f16).any())

            assert_(not (self.all_f16 >= nan).any())
            assert_(not (nan >= self.all_f16).any())

def test_numpy_ufuncs(self):
        # test ufuncs of numpy 1.9.2. see:
        # http://docs.scipy.org/doc/numpy/reference/ufuncs.html

        # some functions are skipped because it may return different result
        # for unicode input depending on numpy version

        for name, idx in compat.iteritems(self.indices):
            for func in [np.exp, np.exp2, np.expm1, np.log, np.log2, np.log10,
                         np.log1p, np.sqrt, np.sin, np.cos, np.tan, np.arcsin,
                         np.arccos, np.arctan, np.sinh, np.cosh, np.tanh,
                         np.arcsinh, np.arccosh, np.arctanh, np.deg2rad,
                         np.rad2deg]:
                if isinstance(idx, pd.tseries.base.DatetimeIndexOpsMixin):
                    # raise TypeError or ValueError (PeriodIndex)
                    # PeriodIndex behavior should be changed in future version
                    with tm.assertRaises(Exception):
                        func(idx)
                elif isinstance(idx, (Float64Index, Int64Index)):
                    # coerces to float (e.g. np.sin)
                    result = func(idx)
                    exp = Index(func(idx.values), name=idx.name)
                    self.assert_index_equal(result, exp)
                    self.assertIsInstance(result, pd.Float64Index)
                else:
                    # raise AttributeError or TypeError
                    if len(idx) == 0:
                        continue
                    else:
                        with tm.assertRaises(Exception):
                            func(idx)

            for func in [np.isfinite, np.isinf, np.isnan, np.signbit]:
                if isinstance(idx, pd.tseries.base.DatetimeIndexOpsMixin):
                    # raise TypeError or ValueError (PeriodIndex)
                    with tm.assertRaises(Exception):
                        func(idx)
                elif isinstance(idx, (Float64Index, Int64Index)):
                    # results in bool array
                    result = func(idx)
                    exp = func(idx.values)
                    self.assertIsInstance(result, np.ndarray)
                    tm.assertNotIsInstance(result, Index)
                else:
                    if len(idx) == 0:
                        continue
                    else:
                        with tm.assertRaises(Exception):
                            func(idx)

def test_half_ufuncs(self):
        """Test the various ufuncs"""

        a = np.array([0, 1, 2, 4, 2], dtype=float16)
        b = np.array([-2, 5, 1, 4, 3], dtype=float16)
        c = np.array([0, -1, -np.inf, np.nan, 6], dtype=float16)

        assert_equal(np.add(a, b), [-2, 6, 3, 8, 5])
        assert_equal(np.subtract(a, b), [2, -4, 1, 0, -1])
        assert_equal(np.multiply(a, b), [0, 5, 2, 16, 6])
        assert_equal(np.divide(a, b), [0, 0.199951171875, 2, 1, 0.66650390625])

        assert_equal(np.equal(a, b), [False, False, False, True, False])
        assert_equal(np.not_equal(a, b), [True, True, True, False, True])
        assert_equal(np.less(a, b), [False, True, False, False, True])
        assert_equal(np.less_equal(a, b), [False, True, False, True, True])
        assert_equal(np.greater(a, b), [True, False, True, False, False])
        assert_equal(np.greater_equal(a, b), [True, False, True, True, False])
        assert_equal(np.logical_and(a, b), [False, True, True, True, True])
        assert_equal(np.logical_or(a, b), [True, True, True, True, True])
        assert_equal(np.logical_xor(a, b), [True, False, False, False, False])
        assert_equal(np.logical_not(a), [True, False, False, False, False])

        assert_equal(np.isnan(c), [False, False, False, True, False])
        assert_equal(np.isinf(c), [False, False, True, False, False])
        assert_equal(np.isfinite(c), [True, True, False, False, True])
        assert_equal(np.signbit(b), [True, False, False, False, False])

        assert_equal(np.copysign(b, a), [2, 5, 1, 4, 3])

        assert_equal(np.maximum(a, b), [0, 5, 2, 4, 3])
        x = np.maximum(b, c)
        assert_(np.isnan(x[3]))
        x[3] = 0
        assert_equal(x, [0, 5, 1, 0, 6])
        assert_equal(np.minimum(a, b), [-2, 1, 1, 4, 2])
        x = np.minimum(b, c)
        assert_(np.isnan(x[3]))
        x[3] = 0
        assert_equal(x, [-2, -1, -np.inf, 0, 3])
        assert_equal(np.fmax(a, b), [0, 5, 2, 4, 3])
        assert_equal(np.fmax(b, c), [0, 5, 1, 4, 6])
        assert_equal(np.fmin(a, b), [-2, 1, 1, 4, 2])
        assert_equal(np.fmin(b, c), [-2, -1, -np.inf, 4, 3])

        assert_equal(np.floor_divide(a, b), [0, 0, 2, 1, 0])
        assert_equal(np.remainder(a, b), [0, 1, 0, 0, 2])
        assert_equal(np.square(b), [4, 25, 1, 16, 9])
        assert_equal(np.reciprocal(b), [-0.5, 0.199951171875, 1, 0.25, 0.333251953125])
        assert_equal(np.ones_like(b), [1, 1, 1, 1, 1])
        assert_equal(np.conjugate(b), b)
        assert_equal(np.absolute(b), [2, 5, 1, 4, 3])
        assert_equal(np.negative(b), [2, -5, -1, -4, -3])
        assert_equal(np.sign(b), [-1, 1, 1, 1, 1])
        assert_equal(np.modf(b), ([0, 0, 0, 0, 0], b))
        assert_equal(np.frexp(b), ([-0.5, 0.625, 0.5, 0.5, 0.75], [2, 3, 1, 3, 2]))
        assert_equal(np.ldexp(b, [0, 1, 2, 4, 2]), [-2, 10, 4, 64, 12])

def test_half_ufuncs(self):
        """Test the various ufuncs"""

        a = np.array([0, 1, 2, 4, 2], dtype=float16)
        b = np.array([-2, 5, 1, 4, 3], dtype=float16)
        c = np.array([0, -1, -np.inf, np.nan, 6], dtype=float16)

        assert_equal(np.add(a, b), [-2, 6, 3, 8, 5])
        assert_equal(np.subtract(a, b), [2, -4, 1, 0, -1])
        assert_equal(np.multiply(a, b), [0, 5, 2, 16, 6])
        assert_equal(np.divide(a, b), [0, 0.199951171875, 2, 1, 0.66650390625])

        assert_equal(np.equal(a, b), [False, False, False, True, False])
        assert_equal(np.not_equal(a, b), [True, True, True, False, True])
        assert_equal(np.less(a, b), [False, True, False, False, True])
        assert_equal(np.less_equal(a, b), [False, True, False, True, True])
        assert_equal(np.greater(a, b), [True, False, True, False, False])
        assert_equal(np.greater_equal(a, b), [True, False, True, True, False])
        assert_equal(np.logical_and(a, b), [False, True, True, True, True])
        assert_equal(np.logical_or(a, b), [True, True, True, True, True])
        assert_equal(np.logical_xor(a, b), [True, False, False, False, False])
        assert_equal(np.logical_not(a), [True, False, False, False, False])

        assert_equal(np.isnan(c), [False, False, False, True, False])
        assert_equal(np.isinf(c), [False, False, True, False, False])
        assert_equal(np.isfinite(c), [True, True, False, False, True])
        assert_equal(np.signbit(b), [True, False, False, False, False])

        assert_equal(np.copysign(b, a), [2, 5, 1, 4, 3])

        assert_equal(np.maximum(a, b), [0, 5, 2, 4, 3])
        x = np.maximum(b, c)
        assert_(np.isnan(x[3]))
        x[3] = 0
        assert_equal(x, [0, 5, 1, 0, 6])
        assert_equal(np.minimum(a, b), [-2, 1, 1, 4, 2])
        x = np.minimum(b, c)
        assert_(np.isnan(x[3]))
        x[3] = 0
        assert_equal(x, [-2, -1, -np.inf, 0, 3])
        assert_equal(np.fmax(a, b), [0, 5, 2, 4, 3])
        assert_equal(np.fmax(b, c), [0, 5, 1, 4, 6])
        assert_equal(np.fmin(a, b), [-2, 1, 1, 4, 2])
        assert_equal(np.fmin(b, c), [-2, -1, -np.inf, 4, 3])

        assert_equal(np.floor_divide(a, b), [0, 0, 2, 1, 0])
        assert_equal(np.remainder(a, b), [0, 1, 0, 0, 2])
        assert_equal(np.square(b), [4, 25, 1, 16, 9])
        assert_equal(np.reciprocal(b), [-0.5, 0.199951171875, 1, 0.25, 0.333251953125])
        assert_equal(np.ones_like(b), [1, 1, 1, 1, 1])
        assert_equal(np.conjugate(b), b)
        assert_equal(np.absolute(b), [2, 5, 1, 4, 3])
        assert_equal(np.negative(b), [2, -5, -1, -4, -3])
        assert_equal(np.sign(b), [-1, 1, 1, 1, 1])
        assert_equal(np.modf(b), ([0, 0, 0, 0, 0], b))
        assert_equal(np.frexp(b), ([-0.5, 0.625, 0.5, 0.5, 0.75], [2, 3, 1, 3, 2]))
        assert_equal(np.ldexp(b, [0, 1, 2, 4, 2]), [-2, 10, 4, 64, 12])