Python sympy.csc函数代码示例

def trig_rule(integral):
    integrand, symbol = integral
    if isinstance(integrand, sympy.sin) or isinstance(integrand, sympy.cos):
        arg = integrand.args[0]

        if not isinstance(arg, sympy.Symbol):
            return  # perhaps a substitution can deal with it

        if isinstance(integrand, sympy.sin):
            func = "sin"
        else:
            func = "cos"

        return TrigRule(func, arg, integrand, symbol)

    if integrand == sympy.sec(symbol) ** 2:
        return TrigRule("sec**2", symbol, integrand, symbol)
    elif integrand == sympy.csc(symbol) ** 2:
        return TrigRule("csc**2", symbol, integrand, symbol)

    if isinstance(integrand, sympy.tan):
        rewritten = sympy.sin(*integrand.args) / sympy.cos(*integrand.args)
    elif isinstance(integrand, sympy.cot):
        rewritten = sympy.cos(*integrand.args) / sympy.sin(*integrand.args)
    elif isinstance(integrand, sympy.sec):
        arg = integrand.args[0]
        rewritten = (sympy.sec(arg) ** 2 + sympy.tan(arg) * sympy.sec(arg)) / (sympy.sec(arg) + sympy.tan(arg))
    elif isinstance(integrand, sympy.csc):
        arg = integrand.args[0]
        rewritten = (sympy.csc(arg) ** 2 + sympy.cot(arg) * sympy.csc(arg)) / (sympy.csc(arg) + sympy.cot(arg))
    else:
        return

    return RewriteRule(rewritten, integral_steps(rewritten, symbol), integrand, symbol)

def test_hyper_as_trig():
    from sympy.simplify.fu import _osborne as o, _osbornei as i, TR12

    eq = sinh(x)**2 + cosh(x)**2
    t, f = hyper_as_trig(eq)
    assert f(fu(t)) == cosh(2*x)
    e, f = hyper_as_trig(tanh(x + y))
    assert f(TR12(e)) == (tanh(x) + tanh(y))/(tanh(x)*tanh(y) + 1)

    d = Dummy()
    assert o(sinh(x), d) == I*sin(x*d)
    assert o(tanh(x), d) == I*tan(x*d)
    assert o(coth(x), d) == cot(x*d)/I
    assert o(cosh(x), d) == cos(x*d)
    assert o(sech(x), d) == sec(x*d)
    assert o(csch(x), d) == csc(x*d)/I
    for func in (sinh, cosh, tanh, coth, sech, csch):
        h = func(pi)
        assert i(o(h, d), d) == h
    # /!\ the _osborne functions are not meant to work
    # in the o(i(trig, d), d) direction so we just check
    # that they work as they are supposed to work
    assert i(cos(x*y + z), y) == cosh(x + z*I)
    assert i(sin(x*y + z), y) == sinh(x + z*I)/I
    assert i(tan(x*y + z), y) == tanh(x + z*I)/I
    assert i(cot(x*y + z), y) == coth(x + z*I)*I
    assert i(sec(x*y + z), y) == sech(x + z*I)
    assert i(csc(x*y + z), y) == csch(x + z*I)*I

def test_periodicity():
    x = Symbol('x')
    y = Symbol('y')

    assert periodicity(sin(2*x), x) == pi
    assert periodicity((-2)*tan(4*x), x) == pi/4
    assert periodicity(sin(x)**2, x) == 2*pi
    assert periodicity(3**tan(3*x), x) == pi/3
    assert periodicity(tan(x)*cos(x), x) == 2*pi
    assert periodicity(sin(x)**(tan(x)), x) == 2*pi
    assert periodicity(tan(x)*sec(x), x) == 2*pi
    assert periodicity(sin(2*x)*cos(2*x) - y, x) == pi/2
    assert periodicity(tan(x) + cot(x), x) == pi
    assert periodicity(sin(x) - cos(2*x), x) == 2*pi
    assert periodicity(sin(x) - 1, x) == 2*pi
    assert periodicity(sin(4*x) + sin(x)*cos(x), x) == pi
    assert periodicity(exp(sin(x)), x) == 2*pi
    assert periodicity(log(cot(2*x)) - sin(cos(2*x)), x) == pi
    assert periodicity(sin(2*x)*exp(tan(x) - csc(2*x)), x) == pi
    assert periodicity(cos(sec(x) - csc(2*x)), x) == 2*pi
    assert periodicity(tan(sin(2*x)), x) == pi
    assert periodicity(2*tan(x)**2, x) == pi

    assert periodicity(sin(x)**2 + cos(x)**2, x) == S.Zero
    assert periodicity(tan(x), y) == S.Zero

    assert periodicity(exp(x), x) is None
    assert periodicity(log(x), x) is None
    assert periodicity(exp(x)**sin(x), x) is None
    assert periodicity(sin(x)**y, y) is None

def test_trigintegrate_mixed():
    assert trigintegrate(sin(x)*sec(x), x) == -log(sin(x)**2 - 1)/2
    assert trigintegrate(sin(x)*csc(x), x) == x
    assert trigintegrate(sin(x)*cot(x), x) == sin(x)

    assert trigintegrate(cos(x)*sec(x), x) == x
    assert trigintegrate(cos(x)*csc(x), x) == log(cos(x)**2 - 1)/2
    assert trigintegrate(cos(x)*tan(x), x) == -cos(x)
    assert trigintegrate(cos(x)*cot(x), x) == log(cos(x) - 1)/2 \
        - log(cos(x) + 1)/2 + cos(x)

def test_manualintegrate_trigonometry():
    assert manualintegrate(sin(x), x) == -cos(x)
    assert manualintegrate(tan(x), x) == -log(cos(x))

    assert manualintegrate(sec(x), x) == log(sec(x) + tan(x))
    assert manualintegrate(csc(x), x) == -log(csc(x) + cot(x))

    assert manualintegrate(sin(x) * cos(x), x) in [sin(x) ** 2 / 2, -cos(x)**2 / 2]
    assert manualintegrate(-sec(x) * tan(x), x) == -sec(x)
    assert manualintegrate(csc(x) * cot(x), x) == -csc(x)

def test_periodicity():
    x = Symbol('x')
    y = Symbol('y')

    assert periodicity(sin(2*x), x) == pi
    assert periodicity((-2)*tan(4*x), x) == pi/4
    assert periodicity(sin(x)**2, x) == 2*pi
    assert periodicity(3**tan(3*x), x) == pi/3
    assert periodicity(tan(x)*cos(x), x) == 2*pi
    assert periodicity(sin(x)**(tan(x)), x) == 2*pi
    assert periodicity(tan(x)*sec(x), x) == 2*pi
    assert periodicity(sin(2*x)*cos(2*x) - y, x) == pi/2
    assert periodicity(tan(x) + cot(x), x) == pi
    assert periodicity(sin(x) - cos(2*x), x) == 2*pi
    assert periodicity(sin(x) - 1, x) == 2*pi
    assert periodicity(sin(4*x) + sin(x)*cos(x), x) == pi
    assert periodicity(exp(sin(x)), x) == 2*pi
    assert periodicity(log(cot(2*x)) - sin(cos(2*x)), x) == pi
    assert periodicity(sin(2*x)*exp(tan(x) - csc(2*x)), x) == pi
    assert periodicity(cos(sec(x) - csc(2*x)), x) == 2*pi
    assert periodicity(tan(sin(2*x)), x) == pi
    assert periodicity(2*tan(x)**2, x) == pi
    assert periodicity(sin(x%4), x) == 4
    assert periodicity(sin(x)%4, x) == 2*pi
    assert periodicity(tan((3*x-2)%4), x) == 4/3
    assert periodicity((sqrt(2)*(x+1)+x) % 3, x) == 3 / (sqrt(2)+1)
    assert periodicity((x**2+1) % x, x) == None

    assert periodicity(sin(x)**2 + cos(x)**2, x) == S.Zero
    assert periodicity(tan(x), y) == S.Zero

    assert periodicity(exp(x), x) is None
    assert periodicity(log(x), x) is None
    assert periodicity(exp(x)**sin(x), x) is None
    assert periodicity(sin(x)**y, y) is None

    assert periodicity(Abs(sin(Abs(sin(x)))),x) == pi
    assert all(periodicity(Abs(f(x)),x) == pi for f in (
        cos, sin, sec, csc, tan, cot))
    assert periodicity(Abs(sin(tan(x))), x) == pi
    assert periodicity(Abs(sin(sin(x) + tan(x))), x) == 2*pi
    assert periodicity(sin(x) > S.Half, x) is 2*pi

    assert periodicity(x > 2, x) is None
    assert periodicity(x**3 - x**2 + 1, x) is None
    assert periodicity(Abs(x), x) is None
    assert periodicity(Abs(x**2 - 1), x) is None

    assert periodicity((x**2 + 4)%2, x) is None
    assert periodicity((E**x)%3, x) is None

def test_manualintegrate_trigpowers():
    assert manualintegrate(sin(x)**2 * cos(x), x) == sin(x)**3 / 3
    assert manualintegrate(sin(x)**2 * cos(x) **2, x) == \
        x / 8 - sin(4*x) / 32
    assert manualintegrate(sin(x) * cos(x)**3, x) == -cos(x)**4 / 4
    assert manualintegrate(sin(x)**3 * cos(x)**2, x) == \
        cos(x)**5 / 5 - cos(x)**3 / 3

    assert manualintegrate(tan(x)**3 * sec(x), x) == sec(x)**3/3 - sec(x)
    assert manualintegrate(tan(x) * sec(x) **2, x) == sec(x)**2/2

    assert manualintegrate(cot(x)**5 * csc(x), x) == \
        -csc(x)**5/5 + 2*csc(x)**3/3 - csc(x)
    assert manualintegrate(cot(x)**2 * csc(x)**6, x) == \
        -cot(x)**7/7 - 2*cot(x)**5/5 - cot(x)**3/3

def test_conv7():
    x = Symbol("x")
    y = Symbol("y")
    assert sin(x/3) == sin(sympy.Symbol("x") / 3)
    assert cos(x/3) == cos(sympy.Symbol("x") / 3)
    assert tan(x/3) == tan(sympy.Symbol("x") / 3)
    assert cot(x/3) == cot(sympy.Symbol("x") / 3)
    assert csc(x/3) == csc(sympy.Symbol("x") / 3)
    assert sec(x/3) == sec(sympy.Symbol("x") / 3)
    assert asin(x/3) == asin(sympy.Symbol("x") / 3)
    assert acos(x/3) == acos(sympy.Symbol("x") / 3)
    assert atan(x/3) == atan(sympy.Symbol("x") / 3)
    assert acot(x/3) == acot(sympy.Symbol("x") / 3)
    assert acsc(x/3) == acsc(sympy.Symbol("x") / 3)
    assert asec(x/3) == asec(sympy.Symbol("x") / 3)

    assert sin(x/3)._sympy_() == sympy.sin(sympy.Symbol("x") / 3)
    assert sin(x/3)._sympy_() != sympy.cos(sympy.Symbol("x") / 3)
    assert cos(x/3)._sympy_() == sympy.cos(sympy.Symbol("x") / 3)
    assert tan(x/3)._sympy_() == sympy.tan(sympy.Symbol("x") / 3)
    assert cot(x/3)._sympy_() == sympy.cot(sympy.Symbol("x") / 3)
    assert csc(x/3)._sympy_() == sympy.csc(sympy.Symbol("x") / 3)
    assert sec(x/3)._sympy_() == sympy.sec(sympy.Symbol("x") / 3)
    assert asin(x/3)._sympy_() == sympy.asin(sympy.Symbol("x") / 3)
    assert acos(x/3)._sympy_() == sympy.acos(sympy.Symbol("x") / 3)
    assert atan(x/3)._sympy_() == sympy.atan(sympy.Symbol("x") / 3)
    assert acot(x/3)._sympy_() == sympy.acot(sympy.Symbol("x") / 3)
    assert acsc(x/3)._sympy_() == sympy.acsc(sympy.Symbol("x") / 3)
    assert asec(x/3)._sympy_() == sympy.asec(sympy.Symbol("x") / 3)

def eval_trig(func, arg, integrand, symbol):
    if func == 'sin':
        return -sympy.cos(arg)
    elif func == 'cos':
        return sympy.sin(arg)
    elif func == 'sec*tan':
        return sympy.sec(arg)
    elif func == 'csc*cot':
        return sympy.csc(arg)

def test_inverses():
    raises(AttributeError, lambda: sin(x).inverse())
    raises(AttributeError, lambda: cos(x).inverse())
    assert tan(x).inverse() == atan
    assert cot(x).inverse() == acot
    raises(AttributeError, lambda: csc(x).inverse())
    raises(AttributeError, lambda: sec(x).inverse())
    assert asin(x).inverse() == sin
    assert acos(x).inverse() == cos
    assert atan(x).inverse() == tan
    assert acot(x).inverse() == cot

def manual_diff(f, symbol):
    """Derivative of f in form expected by find_substitutions

    SymPy's derivatives for some trig functions (like cot) aren't in a form
    that works well with finding substitutions; this replaces the
    derivatives for those particular forms with something that works better.

    """
    if f.args:
        arg = f.args[0]
        if isinstance(f, sympy.tan):
            return arg.diff(symbol) * sympy.sec(arg)**2
        elif isinstance(f, sympy.cot):
            return -arg.diff(symbol) * sympy.csc(arg)**2
        elif isinstance(f, sympy.sec):
            return arg.diff(symbol) * sympy.sec(arg) * sympy.tan(arg)
        elif isinstance(f, sympy.csc):
            return -arg.diff(symbol) * sympy.csc(arg) * sympy.cot(arg)
        elif isinstance(f, sympy.Add):
            return sum([manual_diff(arg, symbol) for arg in f.args])
    return f.diff(symbol)

def eval_trig(func, arg, integrand, symbol):
    if func == "sin":
        return -sympy.cos(arg)
    elif func == "cos":
        return sympy.sin(arg)
    elif func == "sec*tan":
        return sympy.sec(arg)
    elif func == "csc*cot":
        return sympy.csc(arg)
    elif func == "sec**2":
        return sympy.tan(arg)
    elif func == "csc**2":
        return -sympy.cot(arg)

def test_conv7b():
    x = sympy.Symbol("x")
    y = sympy.Symbol("y")
    assert sympify(sympy.sin(x/3)) == sin(Symbol("x") / 3)
    assert sympify(sympy.sin(x/3)) != cos(Symbol("x") / 3)
    assert sympify(sympy.cos(x/3)) == cos(Symbol("x") / 3)
    assert sympify(sympy.tan(x/3)) == tan(Symbol("x") / 3)
    assert sympify(sympy.cot(x/3)) == cot(Symbol("x") / 3)
    assert sympify(sympy.csc(x/3)) == csc(Symbol("x") / 3)
    assert sympify(sympy.sec(x/3)) == sec(Symbol("x") / 3)
    assert sympify(sympy.asin(x/3)) == asin(Symbol("x") / 3)
    assert sympify(sympy.acos(x/3)) == acos(Symbol("x") / 3)
    assert sympify(sympy.atan(x/3)) == atan(Symbol("x") / 3)
    assert sympify(sympy.acot(x/3)) == acot(Symbol("x") / 3)
    assert sympify(sympy.acsc(x/3)) == acsc(Symbol("x") / 3)
    assert sympify(sympy.asec(x/3)) == asec(Symbol("x") / 3)

def test_hyper_as_trig():
    from sympy.simplify.fu import _osborne, _osbornei

    eq = sinh(x)**2 + cosh(x)**2
    t, f = hyper_as_trig(eq)
    assert f(fu(t)) == cosh(2*x)
    assert _osborne(cosh(x)) == cos(x)
    assert _osborne(sinh(x)) == I*sin(x)
    assert _osborne(tanh(x)) == I*tan(x)
    assert _osborne(coth(x)) == cot(x)/I
    assert _osbornei(cos(x)) == cosh(x)
    assert _osbornei(sin(x)) == sinh(x)/I
    assert _osbornei(tan(x)) == tanh(x)/I
    assert _osbornei(cot(x)) == coth(x)*I
    assert _osbornei(sec(x)) == 1/cosh(x)
    assert _osbornei(csc(x)) == I/sinh(x)

def trig_powers_products_rule(integral):
    integrand, symbol = integral

    if any(integrand.has(f) for f in (sympy.sin, sympy.cos)):
        pattern, a, b, m, n = sincos_pattern(symbol)
        match = integrand.match(pattern)

        if match:
            a, b, m, n = match.get(a, 0),match.get(b, 0), match.get(m, 0), match.get(n, 0)
            return multiplexer({
                sincos_botheven_condition: sincos_botheven,
                sincos_sinodd_condition: sincos_sinodd,
                sincos_cosodd_condition: sincos_cosodd
            })((a, b, m, n, integrand, symbol))

    integrand = integrand.subs({
        1 / sympy.cos(symbol): sympy.sec(symbol)
    })

    if any(integrand.has(f) for f in (sympy.tan, sympy.sec)):
        pattern, a, b, m, n = tansec_pattern(symbol)
        match = integrand.match(pattern)

        if match:
            a, b, m, n = match.get(a, 0),match.get(b, 0), match.get(m, 0), match.get(n, 0)
            return multiplexer({
                tansec_tanodd_condition: tansec_tanodd,
                tansec_seceven_condition: tansec_seceven
            })((a, b, m, n, integrand, symbol))

    integrand = integrand.subs({
        1 / sympy.sin(symbol): sympy.csc(symbol),
        1 / sympy.tan(symbol): sympy.cot(symbol),
        sympy.cos(symbol) / sympy.tan(symbol): sympy.cot(symbol)
    })

    if any(integrand.has(f) for f in (sympy.cot, sympy.csc)):
        pattern, a, b, m, n = cotcsc_pattern(symbol)
        match = integrand.match(pattern)

        if match:
            a, b, m, n = match.get(a, 0),match.get(b, 0), match.get(m, 0), match.get(n, 0)
            return multiplexer({
                cotcsc_cotodd_condition: cotcsc_cotodd,
                cotcsc_csceven_condition: cotcsc_csceven
            })((a, b, m, n, integrand, symbol))