我们从Python开源项目中，提取了以下38个代码示例，用于说明如何使用numpy.signbit()。
def test_float(self): # offset for alignment test for i in range(4): assert_array_equal(self.f[i:] > 0, self.ef[i:]) assert_array_equal(self.f[i:] - 1 >= 0, self.ef[i:]) assert_array_equal(self.f[i:] == 0, ~self.ef[i:]) assert_array_equal(-self.f[i:] < 0, self.ef[i:]) assert_array_equal(-self.f[i:] + 1 <= 0, self.ef[i:]) r = self.f[i:] != 0 assert_array_equal(r, self.ef[i:]) r2 = self.f[i:] != np.zeros_like(self.f[i:]) r3 = 0 != self.f[i:] assert_array_equal(r, r2) assert_array_equal(r, r3) # check bool == 0x1 assert_array_equal(r.view(np.int8), r.astype(np.int8)) assert_array_equal(r2.view(np.int8), r2.astype(np.int8)) assert_array_equal(r3.view(np.int8), r3.astype(np.int8)) # isnan on amd64 takes the same code path assert_array_equal(np.isnan(self.nf[i:]), self.ef[i:]) assert_array_equal(np.isfinite(self.nf[i:]), ~self.ef[i:]) assert_array_equal(np.isfinite(self.inff[i:]), ~self.ef[i:]) assert_array_equal(np.isinf(self.inff[i:]), self.efnonan[i:]) assert_array_equal(np.signbit(self.signf[i:]), self.ef[i:])
def test_double(self): # offset for alignment test for i in range(2): assert_array_equal(self.d[i:] > 0, self.ed[i:]) assert_array_equal(self.d[i:] - 1 >= 0, self.ed[i:]) assert_array_equal(self.d[i:] == 0, ~self.ed[i:]) assert_array_equal(-self.d[i:] < 0, self.ed[i:]) assert_array_equal(-self.d[i:] + 1 <= 0, self.ed[i:]) r = self.d[i:] != 0 assert_array_equal(r, self.ed[i:]) r2 = self.d[i:] != np.zeros_like(self.d[i:]) r3 = 0 != self.d[i:] assert_array_equal(r, r2) assert_array_equal(r, r3) # check bool == 0x1 assert_array_equal(r.view(np.int8), r.astype(np.int8)) assert_array_equal(r2.view(np.int8), r2.astype(np.int8)) assert_array_equal(r3.view(np.int8), r3.astype(np.int8)) # isnan on amd64 takes the same code path assert_array_equal(np.isnan(self.nd[i:]), self.ed[i:]) assert_array_equal(np.isfinite(self.nd[i:]), ~self.ed[i:]) assert_array_equal(np.isfinite(self.infd[i:]), ~self.ed[i:]) assert_array_equal(np.isinf(self.infd[i:]), self.ednonan[i:]) assert_array_equal(np.signbit(self.signd[i:]), self.ed[i:])
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])
