本文整理汇总了Python中sympy.functions.elementary.trigonometric.cos函数的典型用法代码示例。如果您正苦于以下问题:Python cos函数的具体用法?Python cos怎么用?Python cos使用的例子?那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。
在下文中一共展示了cos函数的20个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的Python代码示例。
示例1: test_singular_values
def test_singular_values():
x = Symbol('x', real=True)
A = EigenOnlyMatrix([[0, 1*I], [2, 0]])
# if singular values can be sorted, they should be in decreasing order
assert A.singular_values() == [2, 1]
A = eye(3)
A[1, 1] = x
A[2, 2] = 5
vals = A.singular_values()
# since Abs(x) cannot be sorted, test set equality
assert set(vals) == set([5, 1, Abs(x)])
A = EigenOnlyMatrix([[sin(x), cos(x)], [-cos(x), sin(x)]])
vals = [sv.trigsimp() for sv in A.singular_values()]
assert vals == [S(1), S(1)]
A = EigenOnlyMatrix([
[2, 4],
[1, 3],
[0, 0],
[0, 0]
])
assert A.singular_values() == \
[sqrt(sqrt(221) + 15), sqrt(15 - sqrt(221))]
assert A.T.singular_values() == \
[sqrt(sqrt(221) + 15), sqrt(15 - sqrt(221)), 0, 0]
开发者ID:asmeurer,项目名称:sympy,代码行数:28,代码来源:test_commonmatrix.py
示例2: as_real_imag
def as_real_imag(self, deep=True, **hints):
# TODO: Handle deep and hints
n, m, theta, phi = self.args
re = (sqrt((2*n + 1)/(4*pi) * factorial(n - m)/factorial(n + m)) *
cos(m*phi) * assoc_legendre(n, m, cos(theta)))
im = (sqrt((2*n + 1)/(4*pi) * factorial(n - m)/factorial(n + m)) *
sin(m*phi) * assoc_legendre(n, m, cos(theta)))
return (re, im)
开发者ID:asmeurer,项目名称:sympy,代码行数:8,代码来源:spherical_harmonics.py
示例3: test_issue_3554
def test_issue_3554():
x = Symbol("x")
assert (1 / sqrt(1 + cos(x) * sin(x ** 2))).series(x, 0, 7) == 1 - x ** 2 / 2 + 5 * x ** 4 / 8 - 5 * x ** 6 / 8 + O(
x ** 7
)
assert (1 / sqrt(1 + cos(x) * sin(x ** 2))).series(x, 0, 8) == 1 - x ** 2 / 2 + 5 * x ** 4 / 8 - 5 * x ** 6 / 8 + O(
x ** 8
)
开发者ID:cdsousa,项目名称:sympy,代码行数:8,代码来源:test_eval_power.py
示例4: arbitrary_point
def arbitrary_point(self, u=None, v=None):
""" Returns an arbitrary point on the Plane. If given two
parameters, the point ranges over the entire plane. If given 1
or no parameters, returns a point with one parameter which,
when varying from 0 to 2*pi, moves the point in a circle of
radius 1 about p1 of the Plane.
Examples
========
>>> from sympy.geometry import Plane, Ray
>>> from sympy.abc import u, v, t, r
>>> p = Plane((1, 1, 1), normal_vector=(1, 0, 0))
>>> p.arbitrary_point(u, v)
Point3D(1, u + 1, v + 1)
>>> p.arbitrary_point(t)
Point3D(1, cos(t) + 1, sin(t) + 1)
While arbitrary values of u and v can move the point anywhere in
the plane, the single-parameter point can be used to construct a
ray whose arbitrary point can be located at angle t and radius
r from p.p1:
>>> Ray(p.p1, _).arbitrary_point(r)
Point3D(1, r*cos(t) + 1, r*sin(t) + 1)
Returns
=======
Point3D
"""
circle = v is None
if circle:
u = _symbol(u or 't', real=True)
else:
u = _symbol(u or 'u', real=True)
v = _symbol(v or 'v', real=True)
x, y, z = self.normal_vector
a, b, c = self.p1.args
# x1, y1, z1 is a nonzero vector parallel to the plane
if x.is_zero and y.is_zero:
x1, y1, z1 = S.One, S.Zero, S.Zero
else:
x1, y1, z1 = -y, x, S.Zero
# x2, y2, z2 is also parallel to the plane, and orthogonal to x1, y1, z1
x2, y2, z2 = tuple(Matrix((x, y, z)).cross(Matrix((x1, y1, z1))))
if circle:
x1, y1, z1 = (w/sqrt(x1**2 + y1**2 + z1**2) for w in (x1, y1, z1))
x2, y2, z2 = (w/sqrt(x2**2 + y2**2 + z2**2) for w in (x2, y2, z2))
p = Point3D(a + x1*cos(u) + x2*sin(u), \
b + y1*cos(u) + y2*sin(u), \
c + z1*cos(u) + z2*sin(u))
else:
p = Point3D(a + x1*u + x2*v, b + y1*u + y2*v, c + z1*u + z2*v)
return p
开发者ID:asmeurer,项目名称:sympy,代码行数:56,代码来源:plane.py
示例5: test_simplify
def test_simplify():
n = Symbol('n')
f = Function('f')
M = OperationsOnlyMatrix([[ 1/x + 1/y, (x + x*y) / x ],
[ (f(x) + y*f(x))/f(x), 2 * (1/n - cos(n * pi)/n) / pi ]])
assert M.simplify() == Matrix([[ (x + y)/(x * y), 1 + y ],
[ 1 + y, 2*((1 - 1*cos(pi*n))/(pi*n)) ]])
eq = (1 + x)**2
M = OperationsOnlyMatrix([[eq]])
assert M.simplify() == Matrix([[eq]])
assert M.simplify(ratio=oo) == Matrix([[eq.simplify(ratio=oo)]])
开发者ID:asmeurer,项目名称:sympy,代码行数:12,代码来源:test_commonmatrix.py
示例6: test_jacobian2
def test_jacobian2():
rho, phi = symbols("rho,phi")
X = CalculusOnlyMatrix(3, 1, [rho*cos(phi), rho*sin(phi), rho**2])
Y = CalculusOnlyMatrix(2, 1, [rho, phi])
J = Matrix([
[cos(phi), -rho*sin(phi)],
[sin(phi), rho*cos(phi)],
[ 2*rho, 0],
])
assert X.jacobian(Y) == J
m = CalculusOnlyMatrix(2, 2, [1, 2, 3, 4])
m2 = CalculusOnlyMatrix(4, 1, [1, 2, 3, 4])
raises(TypeError, lambda: m.jacobian(Matrix([1,2])))
raises(TypeError, lambda: m2.jacobian(m))
开发者ID:asmeurer,项目名称:sympy,代码行数:15,代码来源:test_commonmatrix.py
示例7: finite_check
def finite_check(f, x, L):
def check_fx(exprs, x):
return x not in exprs.free_symbols
def check_sincos(expr, x, L):
if type(expr) == sin or type(expr) == cos:
sincos_args = expr.args[0]
if sincos_args.match(a*(pi/L)*x + b) is not None:
return True
else:
return False
expr = sincos_to_sum(TR2(TR1(f)))
res_expr = S.Zero
add_coeff = expr.as_coeff_add()
res_expr += add_coeff[0]
a = Wild('a', properties=[lambda k: k.is_Integer, lambda k: k != S.Zero, ])
b = Wild('b', properties=[lambda k: x not in k.free_symbols or k == S.Zero, ])
for s in add_coeff[1]:
mul_coeffs = s.as_coeff_mul()[1]
for t in mul_coeffs:
if not (check_fx(t, x) or check_sincos(t, x, L)):
return False, f
res_expr += TR10(s)
return True, res_expr.collect([sin(a*(pi/L)*x), cos(a*(pi/L)*x)])
开发者ID:nicoguaro,项目名称:sympy,代码行数:29,代码来源:fourier.py
示例8: jn
def jn(n, z):
"""
Spherical Bessel function of the first kind.
Examples:
>>> from sympy import Symbol, jn, sin, cos
>>> z = Symbol("z")
>>> print jn(0, z)
sin(z)/z
>>> jn(1, z) == sin(z)/z**2 - cos(z)/z
True
>>> jn(3, z) ==(1/z - 15/z**3)*cos(z) + (15/z**4 - 6/z**2)*sin(z)
True
The spherical Bessel functions are calculated using the formula:
jn(n, z) == fn(n, z) * sin(z) + (-1)**(n+1) * fn(-n-1, z) * cos(z)
where fn(n, z) are the coefficients, see fn()'s sourcecode for more
information.
"""
n = sympify(n)
z = sympify(z)
return fn(n, z) * sin(z) + (-1)**(n+1) * fn(-n-1, z) * cos(z)
开发者ID:Aang,项目名称:sympy,代码行数:26,代码来源:bessel.py
示例9: _eval_expand_func
def _eval_expand_func(self, **hints):
from sympy import Sum
n = self.args[0]
m = self.args[1] if len(self.args) == 2 else 1
if m == S.One:
if n.is_Add:
off = n.args[0]
nnew = n - off
if off.is_Integer and off.is_positive:
result = [S.One/(nnew + i) for i in range(off, 0, -1)] + [harmonic(nnew)]
return Add(*result)
elif off.is_Integer and off.is_negative:
result = [-S.One/(nnew + i) for i in range(0, off, -1)] + [harmonic(nnew)]
return Add(*result)
if n.is_Rational:
# Expansions for harmonic numbers at general rational arguments (u + p/q)
# Split n as u + p/q with p < q
p, q = n.as_numer_denom()
u = p // q
p = p - u * q
if u.is_nonnegative and p.is_positive and q.is_positive and p < q:
k = Dummy("k")
t1 = q * Sum(1 / (q * k + p), (k, 0, u))
t2 = 2 * Sum(cos((2 * pi * p * k) / S(q)) *
log(sin((pi * k) / S(q))),
(k, 1, floor((q - 1) / S(2))))
t3 = (pi / 2) * cot((pi * p) / q) + log(2 * q)
return t1 + t2 - t3
return self
开发者ID:SungSingSong,项目名称:sympy,代码行数:32,代码来源:numbers.py
示例10: test_issue_7638
def test_issue_7638():
f = pi/log(sqrt(2))
assert ((1 + I)**(I*f/2))**0.3 == (1 + I)**(0.15*I*f)
# if 1/3 -> 1.0/3 this should fail since it cannot be shown that the
# sign will be +/-1; for the previous "small arg" case, it didn't matter
# that this could not be proved
assert (1 + I)**(4*I*f) == ((1 + I)**(12*I*f))**(S(1)/3)
assert (((1 + I)**(I*(1 + 7*f)))**(S(1)/3)).exp == S(1)/3
r = symbols('r', real=True)
assert sqrt(r**2) == abs(r)
assert cbrt(r**3) != r
assert sqrt(Pow(2*I, 5*S.Half)) != (2*I)**(5/S(4))
p = symbols('p', positive=True)
assert cbrt(p**2) == p**(2/S(3))
assert NS(((0.2 + 0.7*I)**(0.7 + 1.0*I))**(0.5 - 0.1*I), 1) == '0.4 + 0.2*I'
assert sqrt(1/(1 + I)) == sqrt(1 - I)/sqrt(2) # or 1/sqrt(1 + I)
e = 1/(1 - sqrt(2))
assert sqrt(e) == I/sqrt(-1 + sqrt(2))
assert e**-S.Half == -I*sqrt(-1 + sqrt(2))
assert sqrt((cos(1)**2 + sin(1)**2 - 1)**(3 + I)).exp == S.Half
assert sqrt(r**(4/S(3))) != r**(2/S(3))
assert sqrt((p + I)**(4/S(3))) == (p + I)**(2/S(3))
assert sqrt((p - p**2*I)**2) == p - p**2*I
assert sqrt((p + r*I)**2) != p + r*I
e = (1 + I/5)
assert sqrt(e**5) == e**(5*S.Half)
assert sqrt(e**6) == e**3
assert sqrt((1 + I*r)**6) != (1 + I*r)**3
开发者ID:certik,项目名称:sympy,代码行数:29,代码来源:test_eval_power.py
示例11: test_literal_evalf_is_number_is_zero_is_comparable
def test_literal_evalf_is_number_is_zero_is_comparable():
from sympy.integrals.integrals import Integral
from sympy.core.symbol import symbols
from sympy.core.function import Function
from sympy.functions.elementary.trigonometric import cos, sin
x = symbols('x')
f = Function('f')
# the following should not be changed without a lot of dicussion
# `foo.is_number` should be equivalent to `not foo.free_symbols`
# it should not attempt anything fancy; see is_zero, is_constant
# and equals for more rigorous tests.
assert f(1).is_number is True
i = Integral(0, (x, x, x))
# expressions that are symbolically 0 can be difficult to prove
# so in case there is some easy way to know if something is 0
# it should appear in the is_zero property for that object;
# if is_zero is true evalf should always be able to compute that
# zero
assert i.n() == 0
assert i.is_zero
assert i.is_number is False
assert i.evalf(2, strict=False) == 0
# issue 10268
n = sin(1)**2 + cos(1)**2 - 1
assert n.is_comparable is False
assert n.n(2).is_comparable is False
assert n.n(2).n(2).is_comparable
开发者ID:A-turing-machine,项目名称:sympy,代码行数:29,代码来源:test_basic.py
示例12: eval
def eval(cls, n, x):
if not n.is_Number:
# Symbolic result U_n(x)
# U_n(-x) ---> (-1)**n * U_n(x)
if x.could_extract_minus_sign():
return S.NegativeOne**n * chebyshevu(n, -x)
# U_{-n}(x) ---> -U_{n-2}(x)
if n.could_extract_minus_sign():
if n == S.NegativeOne:
return S.Zero
else:
return -chebyshevu(-n - 2, x)
# We can evaluate for some special values of x
if x == S.Zero:
return cos(S.Half * S.Pi * n)
if x == S.One:
return S.One + n
elif x == S.Infinity:
return S.Infinity
else:
# n is a given fixed integer, evaluate into polynomial
if n.is_negative:
# U_{-n}(x) ---> -U_{n-2}(x)
if n == S.NegativeOne:
return S.Zero
else:
return -cls._eval_at_order(-n - 2, x)
else:
return cls._eval_at_order(n, x)
开发者ID:ChaliZhg,项目名称:sympy,代码行数:29,代码来源:polynomials.py
示例13: _eval_term
def _eval_term(self, pt):
if pt == 0:
return self.a0
_term = self.an.get(pt, S.Zero) * cos(pt * (pi / self.L) * self.x) \
+ self.bn.get(pt, S.Zero) * sin(pt * (pi / self.L) * self.x)
return _term
开发者ID:asmeurer,项目名称:sympy,代码行数:7,代码来源:fourier.py
示例14: __new__
def __new__(cls, f, limits, exprs):
if not (type(exprs) == tuple and len(exprs) == 3): # exprs is not of form (a0, an, bn)
# Converts the expression to fourier form
c, e = exprs.as_coeff_add()
rexpr = c + Add(*[TR10(i) for i in e])
a0, exp_ls = rexpr.expand(trig=False, power_base=False, power_exp=False, log=False).as_coeff_add()
x = limits[0]
L = abs(limits[2] - limits[1]) / 2
a = Wild('a', properties=[lambda k: k.is_Integer, lambda k: k is not S.Zero, ])
b = Wild('b', properties=[lambda k: x not in k.free_symbols, ])
an = dict()
bn = dict()
# separates the coefficients of sin and cos terms in dictionaries an, and bn
for p in exp_ls:
t = p.match(b * cos(a * (pi / L) * x))
q = p.match(b * sin(a * (pi / L) * x))
if t:
an[t[a]] = t[b] + an.get(t[a], S.Zero)
elif q:
bn[q[a]] = q[b] + bn.get(q[a], S.Zero)
else:
a0 += p
exprs = (a0, an, bn)
args = map(sympify, (f, limits, exprs))
return Expr.__new__(cls, *args)
开发者ID:asmeurer,项目名称:sympy,代码行数:32,代码来源:fourier.py
示例15: test_issue_3554s
def test_issue_3554s():
x = Symbol("x")
assert (1 / sqrt(1 + cos(x) * sin(x ** 2))).series(
x, 0, 15
) == 1 - x ** 2 / 2 + 5 * x ** 4 / 8 - 5 * x ** 6 / 8 + 4039 * x ** 8 / 5760 - 5393 * x ** 10 / 6720 + 13607537 * x ** 12 / 14515200 - 532056047 * x ** 14 / 479001600 + O(
x ** 15
)
开发者ID:cdsousa,项目名称:sympy,代码行数:7,代码来源:test_eval_power.py
示例16: fourier_cos_seq
def fourier_cos_seq(func, limits, n):
"""Returns the cos sequence in a Fourier series"""
from sympy.integrals import integrate
x, L = limits[0], limits[2] - limits[1]
cos_term = cos(2*n*pi*x / L)
formula = 2 * cos_term * integrate(func * cos_term, limits) / L
a0 = formula.subs(n, S.Zero) / 2
return a0, SeqFormula(2 * cos_term * integrate(func * cos_term, limits)
/ L, (n, 1, oo))
开发者ID:asmeurer,项目名称:sympy,代码行数:9,代码来源:fourier.py
示例17: _eval_expand_func
def _eval_expand_func(self, **hints):
n, m, theta, phi = self.args
rv = (
sqrt((2 * n + 1) / (4 * pi) * C.factorial(n - m) / C.factorial(n + m))
* C.exp(I * m * phi)
* assoc_legendre(n, m, C.cos(theta))
)
# We can do this because of the range of theta
return rv.subs(sqrt(-cos(theta) ** 2 + 1), sin(theta))
开发者ID:vramana,项目名称:sympy,代码行数:9,代码来源:spherical_harmonics.py
示例18: random_point
def random_point(self, seed=None):
"""A random point on the ellipse.
Returns
=======
point : Point
Examples
========
>>> from sympy import Point, Ellipse, Segment
>>> e1 = Ellipse(Point(0, 0), 3, 2)
>>> e1.random_point() # gives some random point
Point2D(...)
>>> p1 = e1.random_point(seed=0); p1.n(2)
Point2D(2.1, 1.4)
Notes
=====
When creating a random point, one may simply replace the
parameter with a random number. When doing so, however, the
random number should be made a Rational or else the point
may not test as being in the ellipse:
>>> from sympy.abc import t
>>> from sympy import Rational
>>> arb = e1.arbitrary_point(t); arb
Point2D(3*cos(t), 2*sin(t))
>>> arb.subs(t, .1) in e1
False
>>> arb.subs(t, Rational(.1)) in e1
True
>>> arb.subs(t, Rational('.1')) in e1
True
See Also
========
sympy.geometry.point.Point
arbitrary_point : Returns parameterized point on ellipse
"""
from sympy import sin, cos, Rational
t = _symbol('t', real=True)
x, y = self.arbitrary_point(t).args
# get a random value in [-1, 1) corresponding to cos(t)
# and confirm that it will test as being in the ellipse
if seed is not None:
rng = random.Random(seed)
else:
rng = random
# simplify this now or else the Float will turn s into a Float
r = Rational(rng.random())
c = 2*r - 1
s = sqrt(1 - c**2)
return Point(x.subs(cos(t), c), y.subs(sin(t), s))
开发者ID:aprasanna,项目名称:sympy,代码行数:56,代码来源:ellipse.py
示例19: test_expand
def test_expand():
m0 = OperationsOnlyMatrix([[x*(x + y), 2], [((x + y)*y)*x, x*(y + x*(x + y))]])
# Test if expand() returns a matrix
m1 = m0.expand()
assert m1 == Matrix(
[[x*y + x**2, 2], [x*y**2 + y*x**2, x*y + y*x**2 + x**3]])
a = Symbol('a', real=True)
assert OperationsOnlyMatrix(1, 1, [exp(I*a)]).expand(complex=True) == \
Matrix([cos(a) + I*sin(a)])
开发者ID:asmeurer,项目名称:sympy,代码行数:11,代码来源:test_commonmatrix.py
示例20: taylor_term
def taylor_term(n, x, *previous_terms):
if n < 0:
return S.Zero
else:
x = sympify(x)
if len(previous_terms) > 1:
p = previous_terms[-1]
return (3**(S(1)/3)*x * Abs(sin(2*pi*(n + S.One)/S(3))) * C.factorial((n - S.One)/S(3)) /
((n + S.One) * Abs(cos(2*pi*(n + S.Half)/S(3))) * C.factorial((n - 2)/S(3))) * p)
else:
return (S.One/(root(3, 6)*pi) * gamma((n + S.One)/S(3)) * Abs(sin(2*pi*(n + S.One)/S(3))) /
C.factorial(n) * (root(3, 3)*x)**n)
开发者ID:AdrianPotter,项目名称:sympy,代码行数:12,代码来源:bessel.py
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