Python cmath.tanh() Examples

def testTanhSign(self):
        for z in complex_zeros:
            self.assertComplexIdentical(cmath.tanh(z), z)

    # The algorithm used for atan and atanh makes use of the system
    # log1p function; If that system function doesn't respect the sign
    # of zero, then atan and atanh will also have difficulties with
    # the sign of complex zeros. 

def testTanhSign(self):
        for z in complex_zeros:
            self.assertComplexIdentical(cmath.tanh(z), z)

    # The algorithm used for atan and atanh makes use of the system
    # log1p function; If that system function doesn't respect the sign
    # of zero, then atan and atanh will also have difficulties with
    # the sign of complex zeros. 

def TANH(df, price='Close'):
    """
    Hyperbolic Tangent
    Returns: list of floats = jhta.TANH(df, price='Close')
    """
    return [cmath.tanh(df[price][i]).real for i in range(len(df[price]))] 

def testTanhSign(self):
        for z in complex_zeros:
            self.assertComplexIdentical(cmath.tanh(z), z)

    # The algorithm used for atan and atanh makes use of the system
    # log1p function; If that system function doesn't respect the sign
    # of zero, then atan and atanh will also have difficulties with
    # the sign of complex zeros. 

def test_tanh(self):
        self.assertAlmostEqual(complex(1.00071, 0.00490826),
                               cmath.tanh(complex(3, 4))) 

def test_tanh(self):
        self.assertAlmostEqual(complex(1.00071, 0.00490826),
                               cmath.tanh(complex(3, 4))) 

def test_trig_hyperb_basic():
    for x in (list(range(100)) + list(range(-100,0))):
        t = x / 4.1
        assert cos(mpf(t)).ae(math.cos(t))
        assert sin(mpf(t)).ae(math.sin(t))
        assert tan(mpf(t)).ae(math.tan(t))
        assert cosh(mpf(t)).ae(math.cosh(t))
        assert sinh(mpf(t)).ae(math.sinh(t))
        assert tanh(mpf(t)).ae(math.tanh(t))
    assert sin(1+1j).ae(cmath.sin(1+1j))
    assert sin(-4-3.6j).ae(cmath.sin(-4-3.6j))
    assert cos(1+1j).ae(cmath.cos(1+1j))
    assert cos(-4-3.6j).ae(cmath.cos(-4-3.6j)) 

def test_invhyperb_inaccuracy():
    mp.dps = 15
    assert (asinh(1e-5)*10**5).ae(0.99999999998333333)
    assert (asinh(1e-10)*10**10).ae(1)
    assert (asinh(1e-50)*10**50).ae(1)
    assert (asinh(-1e-5)*10**5).ae(-0.99999999998333333)
    assert (asinh(-1e-10)*10**10).ae(-1)
    assert (asinh(-1e-50)*10**50).ae(-1)
    assert asinh(10**20).ae(46.744849040440862)
    assert asinh(-10**20).ae(-46.744849040440862)
    assert (tanh(1e-10)*10**10).ae(1)
    assert (tanh(-1e-10)*10**10).ae(-1)
    assert (atanh(1e-10)*10**10).ae(1)
    assert (atanh(-1e-10)*10**10).ae(-1) 

def test_complex_functions():
    for x in (list(range(10)) + list(range(-10,0))):
        for y in (list(range(10)) + list(range(-10,0))):
            z = complex(x, y)/4.3 + 0.01j
            assert exp(mpc(z)).ae(cmath.exp(z))
            assert log(mpc(z)).ae(cmath.log(z))
            assert cos(mpc(z)).ae(cmath.cos(z))
            assert sin(mpc(z)).ae(cmath.sin(z))
            assert tan(mpc(z)).ae(cmath.tan(z))
            assert sinh(mpc(z)).ae(cmath.sinh(z))
            assert cosh(mpc(z)).ae(cmath.cosh(z))
            assert tanh(mpc(z)).ae(cmath.tanh(z)) 

def test_tanh():
    mp.dps = 15
    assert tanh(0) == 0
    assert tanh(inf) == 1
    assert tanh(-inf) == -1
    assert isnan(tanh(nan))
    assert tanh(mpc('inf', '0')) == 1 

def test_tanh(self):
        self.assertAlmostEqual(complex(1.00071, 0.00490826),
                               cmath.tanh(complex(3, 4))) 

def test_cmath_matches_math(self):
        # check that corresponding cmath and math functions are equal
        # for floats in the appropriate range

        # test_values in (0, 1)
        test_values = [0.01, 0.1, 0.2, 0.5, 0.9, 0.99]

        # test_values for functions defined on [-1., 1.]
        unit_interval = test_values + [-x for x in test_values] + \
            [0., 1., -1.]

        # test_values for log, log10, sqrt
        positive = test_values + [1.] + [1./x for x in test_values]
        nonnegative = [0.] + positive

        # test_values for functions defined on the whole real line
        real_line = [0.] + positive + [-x for x in positive]

        test_functions = {
            'acos' : unit_interval,
            'asin' : unit_interval,
            'atan' : real_line,
            'cos' : real_line,
            'cosh' : real_line,
            'exp' : real_line,
            'log' : positive,
            'log10' : positive,
            'sin' : real_line,
            'sinh' : real_line,
            'sqrt' : nonnegative,
            'tan' : real_line,
            'tanh' : real_line}

        for fn, values in test_functions.items():
            float_fn = getattr(math, fn)
            complex_fn = getattr(cmath, fn)
            for v in values:
                z = complex_fn(v)
                self.rAssertAlmostEqual(float_fn(v), z.real)
                self.assertEqual(0., z.imag)

        # test two-argument version of log with various bases
        for base in [0.5, 2., 10.]:
            for v in positive:
                z = cmath.log(v, base)
                self.rAssertAlmostEqual(math.log(v, base), z.real)
                self.assertEqual(0., z.imag) 

def test_cmath_matches_math(self):
        # check that corresponding cmath and math functions are equal
        # for floats in the appropriate range

        # test_values in (0, 1)
        test_values = [0.01, 0.1, 0.2, 0.5, 0.9, 0.99]

        # test_values for functions defined on [-1., 1.]
        unit_interval = test_values + [-x for x in test_values] + \
            [0., 1., -1.]

        # test_values for log, log10, sqrt
        positive = test_values + [1.] + [1./x for x in test_values]
        nonnegative = [0.] + positive

        # test_values for functions defined on the whole real line
        real_line = [0.] + positive + [-x for x in positive]

        test_functions = {
            'acos' : unit_interval,
            'asin' : unit_interval,
            'atan' : real_line,
            'cos' : real_line,
            'cosh' : real_line,
            'exp' : real_line,
            'log' : positive,
            'log10' : positive,
            'sin' : real_line,
            'sinh' : real_line,
            'sqrt' : nonnegative,
            'tan' : real_line,
            'tanh' : real_line}

        for fn, values in test_functions.items():
            float_fn = getattr(math, fn)
            complex_fn = getattr(cmath, fn)
            for v in values:
                z = complex_fn(v)
                self.rAssertAlmostEqual(float_fn(v), z.real)
                self.assertEqual(0., z.imag)

        # test two-argument version of log with various bases
        for base in [0.5, 2., 10.]:
            for v in positive:
                z = cmath.log(v, base)
                self.rAssertAlmostEqual(math.log(v, base), z.real)
                self.assertEqual(0., z.imag) 

def test_cmath_matches_math(self):
        # check that corresponding cmath and math functions are equal
        # for floats in the appropriate range

        # test_values in (0, 1)
        test_values = [0.01, 0.1, 0.2, 0.5, 0.9, 0.99]

        # test_values for functions defined on [-1., 1.]
        unit_interval = test_values + [-x for x in test_values] + \
            [0., 1., -1.]

        # test_values for log, log10, sqrt
        positive = test_values + [1.] + [1./x for x in test_values]
        nonnegative = [0.] + positive

        # test_values for functions defined on the whole real line
        real_line = [0.] + positive + [-x for x in positive]

        test_functions = {
            'acos' : unit_interval,
            'asin' : unit_interval,
            'atan' : real_line,
            'cos' : real_line,
            'cosh' : real_line,
            'exp' : real_line,
            'log' : positive,
            'log10' : positive,
            'sin' : real_line,
            'sinh' : real_line,
            'sqrt' : nonnegative,
            'tan' : real_line,
            'tanh' : real_line}

        for fn, values in test_functions.items():
            float_fn = getattr(math, fn)
            complex_fn = getattr(cmath, fn)
            for v in values:
                z = complex_fn(v)
                self.rAssertAlmostEqual(float_fn(v), z.real)
                self.assertEqual(0., z.imag)

        # test two-argument version of log with various bases
        for base in [0.5, 2., 10.]:
            for v in positive:
                z = cmath.log(v, base)
                self.rAssertAlmostEqual(math.log(v, base), z.real)
                self.assertEqual(0., z.imag) 

def test_perturbation_rounding():
    mp.dps = 100
    a = pi/10**50
    b = -pi/10**50
    c = 1 + a
    d = 1 + b
    mp.dps = 15
    assert exp(a) == 1
    assert exp(a, rounding='c') > 1
    assert exp(b, rounding='c') == 1
    assert exp(a, rounding='f') == 1
    assert exp(b, rounding='f') < 1
    assert cos(a) == 1
    assert cos(a, rounding='c') == 1
    assert cos(b, rounding='c') == 1
    assert cos(a, rounding='f') < 1
    assert cos(b, rounding='f') < 1
    for f in [sin, atan, asinh, tanh]:
        assert f(a) == +a
        assert f(a, rounding='c') > a
        assert f(a, rounding='f') < a
        assert f(b) == +b
        assert f(b, rounding='c') > b
        assert f(b, rounding='f') < b
    for f in [asin, tan, sinh, atanh]:
        assert f(a) == +a
        assert f(b) == +b
        assert f(a, rounding='c') > a
        assert f(b, rounding='c') > b
        assert f(a, rounding='f') < a
        assert f(b, rounding='f') < b
    assert ln(c) == +a
    assert ln(d) == +b
    assert ln(c, rounding='c') > a
    assert ln(c, rounding='f') < a
    assert ln(d, rounding='c') > b
    assert ln(d, rounding='f') < b
    assert cosh(a) == 1
    assert cosh(b) == 1
    assert cosh(a, rounding='c') > 1
    assert cosh(b, rounding='c') > 1
    assert cosh(a, rounding='f') == 1
    assert cosh(b, rounding='f') == 1