def verify_numerically(f, g, z=None, tol=1.0e-6, a=2, b=-1, c=3, d=1):
"""
Test numerically that f and g agree when evaluated in the argument z.
If z is None, all symbols will be tested. This routine does not test
whether there are Floats present with precision higher than 15 digits
so if there are, your results may not be what you expect due to round-
off errors.
Examples
========
>>> from sympy import sin, cos
>>> from sympy.abc import x
>>> from sympy.core.random import verify_numerically as tn
>>> tn(sin(x)**2 + cos(x)**2, 1, x)
True
"""
from sympy.core.symbol import Symbol
from sympy.core.sympify import sympify
from sympy.core.numbers import comp
f, g = (sympify(i) for i in (f, g))
if z is None:
z = f.free_symbols | g.free_symbols
elif isinstance(z, Symbol):
z = [z]
reps = list(zip(z, [random_complex_number(a, b, c, d) for _ in z]))
z1 = f.subs(reps).n()
z2 = g.subs(reps).n()
return comp(z1, z2, tol)
def test_H():
X = Normal('X', 0, 1)
D = Die('D', sides=4)
G = Geometric('G', 0.5)
assert H(X, X > 0) == -log(2) / 2 + S(1) / 2 + log(pi) / 2
assert H(D, D > 2) == log(2)
assert comp(H(G).evalf().round(2), 1.39)
def test_H():
X = Normal("X", 0, 1)
D = Die("D", sides=4)
G = Geometric("G", 0.5)
assert H(X, X > 0) == -log(2) / 2 + S.Half + log(pi) / 2
assert H(D, D > 2) == log(2)
assert comp(H(G).evalf().round(2), 1.39)
def test_JointPSpace_marginal_distribution():
T = MultivariateT('T', [0, 0], [[1, 0], [0, 1]], 2)
assert marginal_distribution(T, T[1])(x) == sqrt(2) * (x**2 + 2) / (
8 * polar_lift(x**2 / 2 + 1)**Rational(5, 2))
assert integrate(marginal_distribution(T, 1)(x), (x, -oo, oo)) == 1
t = MultivariateT('T', [0, 0, 0], [[1, 0, 0], [0, 1, 0], [0, 0, 1]], 3)
assert comp(marginal_distribution(t, 0)(1).evalf(), 0.2, .01)
def test_JointPSpace_marginal_distribution():
T = MultivariateT('T', [0, 0], [[1, 0], [0, 1]], 2)
got = marginal_distribution(T, T[1])(x)
ans = sqrt(2) * (x**2 / 2 + 1) / (4 * polar_lift(x**2 / 2 + 1)**(S(5) / 2))
assert got == ans, got
assert integrate(marginal_distribution(T, 1)(x), (x, -oo, oo)) == 1
t = MultivariateT('T', [0, 0, 0], [[1, 0, 0], [0, 1, 0], [0, 0, 1]], 3)
assert comp(marginal_distribution(t, 0)(1).evalf(), 0.2, .01)
def test_JointPSpace_marginal_distribution():
from sympy.stats.joint_rv_types import MultivariateT
from sympy import polar_lift
T = MultivariateT('T', [0, 0], [[1, 0], [0, 1]], 2)
assert marginal_distribution(T, T[1])(x) == sqrt(2)*(x**2 + 2)/(
8*polar_lift(x**2/2 + 1)**(S(5)/2))
assert integrate(marginal_distribution(T, 1)(x), (x, -oo, oo)) == 1
t = MultivariateT('T', [0, 0, 0], [[1, 0, 0], [0, 1, 0], [0, 0, 1]], 3)
assert comp(marginal_distribution(t, 0)(1).evalf(), 0.2, .01)
def test_comp():
# sqrt(2) = 1.414213 5623730950...
a = sqrt(2).n(7)
assert comp(a, 1.41421346) is False
assert comp(a, 1.41421347)
assert comp(a, 1.41421366)
assert comp(a, 1.41421367) is False
assert comp(sqrt(2).n(2), '1.4')
assert comp(sqrt(2).n(2), Float(1.4, 2), '')
raises(ValueError, lambda: comp(sqrt(2).n(2), 1.4, ''))
assert comp(sqrt(2).n(2), Float(1.4, 3), '') is False
def test_comp():
# sqrt(2) = 1.414213 5623730950...
a = sqrt(2).n(7)
assert comp(a, 1.41421346) is False
assert comp(a, 1.41421347)
assert comp(a, 1.41421366)
assert comp(a, 1.41421367) is False
assert comp(sqrt(2).n(2), '1.4')
assert comp(sqrt(2).n(2), Float(1.4, 2), '')
raises(ValueError, lambda: comp(sqrt(2).n(2), 1.4, ''))
assert comp(sqrt(2).n(2), Float(1.4, 3), '') is False
def test_NegativeMultinomial():
from sympy.stats.joint_rv_types import NegativeMultinomial
k0, x1, x2, x3, x4 = symbols('k0, x1, x2, x3, x4', nonnegative=True, integer=True)
p1, p2, p3, p4 = symbols('p1, p2, p3, p4', positive=True)
p1_f = symbols('p1_f', negative=True)
N = NegativeMultinomial('N', 4, [p1, p2, p3, p4])
C = NegativeMultinomial('C', 4, 0.1, 0.2, 0.3)
g = gamma
f = factorial
assert simplify(density(N)(x1, x2, x3, x4) -
p1**x1*p2**x2*p3**x3*p4**x4*(-p1 - p2 - p3 - p4 + 1)**4*g(x1 + x2 +
x3 + x4 + 4)/(6*f(x1)*f(x2)*f(x3)*f(x4))) is S.Zero
assert comp(marginal_distribution(C, C[0])(1).evalf(), 0.33, .01)
raises(ValueError, lambda: NegativeMultinomial('b1', 5, [p1, p2, p3, p1_f]))
raises(ValueError, lambda: NegativeMultinomial('b2', k0, 0.5, 0.4, 0.3, 0.4))
def test_derivative_numerically(f, z, tol=1.0e-6, a=2, b=-1, c=3, d=1):
"""
Test numerically that the symbolically computed derivative of f
with respect to z is correct.
This routine does not test whether there are Floats present with
precision higher than 15 digits so if there are, your results may
not be what you expect due to round-off errors.
Examples
========
>>> from sympy import sin
>>> from sympy.abc import x
>>> from sympy.utilities.randtest import test_derivative_numerically as td
>>> td(sin(x), x)
True
"""
from sympy.core.function import Derivative
z0 = random_complex_number(a, b, c, d)
f1 = f.diff(z).subs(z, z0)
f2 = Derivative(f, z).doit_numerically(z0)
return comp(f1.n(), f2.n(), tol)
def test_derivative_numerically(f, z, tol=1.0e-6, a=2, b=-1, c=3, d=1):
"""
Test numerically that the symbolically computed derivative of f
with respect to z is correct.
This routine does not test whether there are Floats present with
precision higher than 15 digits so if there are, your results may
not be what you expect due to round-off errors.
Examples
========
>>> from sympy import sin
>>> from sympy.abc import x
>>> from sympy.utilities.randtest import test_derivative_numerically as td
>>> td(sin(x), x)
True
"""
from sympy.core.function import Derivative
z0 = random_complex_number(a, b, c, d)
f1 = f.diff(z).subs(z, z0)
f2 = Derivative(f, z).doit_numerically(z0)
return comp(f1.n(), f2.n(), tol)
def verify_numerically(f, g, z=None, tol=1.0e-6, a=2, b=-1, c=3, d=1):
"""
Test numerically that f and g agree when evaluated in the argument z.
If z is None, all symbols will be tested. This routine does not test
whether there are Floats present with precision higher than 15 digits
so if there are, your results may not be what you expect due to round-
off errors.
Examples
========
>>> from sympy import sin, cos
>>> from sympy.abc import x
>>> from sympy.utilities.randtest import verify_numerically as tn
>>> tn(sin(x)**2 + cos(x)**2, 1, x)
True
"""
f, g, z = Tuple(f, g, z)
z = [z] if isinstance(z, Symbol) else (f.free_symbols | g.free_symbols)
reps = list(zip(z, [random_complex_number(a, b, c, d) for zi in z]))
z1 = f.subs(reps).n()
z2 = g.subs(reps).n()
return comp(z1, z2, tol)
def roots_quintic(f):
"""
Calculate exact roots of a solvable quintic
"""
result = []
coeff_5, coeff_4, p, q, r, s = f.all_coeffs()
# Eqn must be of the form x^5 + px^3 + qx^2 + rx + s
if coeff_4:
return result
if coeff_5 != 1:
l = [p/coeff_5, q/coeff_5, r/coeff_5, s/coeff_5]
if not all(coeff.is_Rational for coeff in l):
return result
f = Poly(f/coeff_5)
quintic = PolyQuintic(f)
# Eqn standardized. Algo for solving starts here
if not f.is_irreducible:
return result
f20 = quintic.f20
# Check if f20 has linear factors over domain Z
if f20.is_irreducible:
return result
# Now, we know that f is solvable
for _factor in f20.factor_list()[1]:
if _factor[0].is_linear:
theta = _factor[0].root(0)
break
d = discriminant(f)
delta = sqrt(d)
# zeta = a fifth root of unity
zeta1, zeta2, zeta3, zeta4 = quintic.zeta
T = quintic.T(theta, d)
tol = S(1e-10)
alpha = T[1] + T[2]*delta
alpha_bar = T[1] - T[2]*delta
beta = T[3] + T[4]*delta
beta_bar = T[3] - T[4]*delta
disc = alpha**2 - 4*beta
disc_bar = alpha_bar**2 - 4*beta_bar
l0 = quintic.l0(theta)
l1 = _quintic_simplify((-alpha + sqrt(disc)) / S(2))
l4 = _quintic_simplify((-alpha - sqrt(disc)) / S(2))
l2 = _quintic_simplify((-alpha_bar + sqrt(disc_bar)) / S(2))
l3 = _quintic_simplify((-alpha_bar - sqrt(disc_bar)) / S(2))
order = quintic.order(theta, d)
test = (order*delta.n()) - ( (l1.n() - l4.n())*(l2.n() - l3.n()) )
# Comparing floats
if not comp(test, 0, tol):
l2, l3 = l3, l2
# Now we have correct order of l's
R1 = l0 + l1*zeta1 + l2*zeta2 + l3*zeta3 + l4*zeta4
R2 = l0 + l3*zeta1 + l1*zeta2 + l4*zeta3 + l2*zeta4
R3 = l0 + l2*zeta1 + l4*zeta2 + l1*zeta3 + l3*zeta4
R4 = l0 + l4*zeta1 + l3*zeta2 + l2*zeta3 + l1*zeta4
Res = [None, [None]*5, [None]*5, [None]*5, [None]*5]
Res_n = [None, [None]*5, [None]*5, [None]*5, [None]*5]
sol = Symbol('sol')
# Simplifying improves performance a lot for exact expressions
R1 = _quintic_simplify(R1)
R2 = _quintic_simplify(R2)
R3 = _quintic_simplify(R3)
R4 = _quintic_simplify(R4)
# Solve imported here. Causing problems if imported as 'solve'
# and hence the changed name
from sympy.solvers.solvers import solve as _solve
a, b = symbols('a b', cls=Dummy)
_sol = _solve( sol**5 - a - I*b, sol)
for i in range(5):
_sol[i] = factor(_sol[i])
R1 = R1.as_real_imag()
R2 = R2.as_real_imag()
R3 = R3.as_real_imag()
R4 = R4.as_real_imag()
for i, currentroot in enumerate(_sol):
Res[1][i] = _quintic_simplify(currentroot.subs({ a: R1[0], b: R1[1] }))
Res[2][i] = _quintic_simplify(currentroot.subs({ a: R2[0], b: R2[1] }))
Res[3][i] = _quintic_simplify(currentroot.subs({ a: R3[0], b: R3[1] }))
Res[4][i] = _quintic_simplify(currentroot.subs({ a: R4[0], b: R4[1] }))
for i in range(1, 5):
for j in range(5):
Res_n[i][j] = Res[i][j].n()
Res[i][j] = _quintic_simplify(Res[i][j])
r1 = Res[1][0]
r1_n = Res_n[1][0]
for i in range(5):
if comp(im(r1_n*Res_n[4][i]), 0, tol):
r4 = Res[4][i]
break
# Now we have various Res values. Each will be a list of five
# values. We have to pick one r value from those five for each Res
u, v = quintic.uv(theta, d)
testplus = (u + v*delta*sqrt(5)).n()
testminus = (u - v*delta*sqrt(5)).n()
# Evaluated numbers suffixed with _n
# We will use evaluated numbers for calculation. Much faster.
r4_n = r4.n()
r2 = r3 = None
for i in range(5):
r2temp_n = Res_n[2][i]
for j in range(5):
# Again storing away the exact number and using
# evaluated numbers in computations
r3temp_n = Res_n[3][j]
if (comp((r1_n*r2temp_n**2 + r4_n*r3temp_n**2 - testplus).n(), 0, tol) and
comp((r3temp_n*r1_n**2 + r2temp_n*r4_n**2 - testminus).n(), 0, tol)):
r2 = Res[2][i]
r3 = Res[3][j]
break
if r2:
break
# Now, we have r's so we can get roots
x1 = (r1 + r2 + r3 + r4)/5
x2 = (r1*zeta4 + r2*zeta3 + r3*zeta2 + r4*zeta1)/5
x3 = (r1*zeta3 + r2*zeta1 + r3*zeta4 + r4*zeta2)/5
x4 = (r1*zeta2 + r2*zeta4 + r3*zeta1 + r4*zeta3)/5
x5 = (r1*zeta1 + r2*zeta2 + r3*zeta3 + r4*zeta4)/5
result = [x1, x2, x3, x4, x5]
# Now check if solutions are distinct
saw = set()
for r in result:
r = r.n(2)
if r in saw:
# Roots were identical. Abort, return []
# and fall back to usual solve
return []
saw.add(r)
return result
hyperfocal_distance,
transverse_magnification)
from sympy.physics.optics.medium import Medium
from sympy.physics.units import e0
from sympy.core.numbers import oo
from sympy.core.symbol import symbols
from sympy.functions.elementary.miscellaneous import sqrt
from sympy.matrices.dense import Matrix
from sympy.geometry.point import Point3D
from sympy.geometry.line import Ray3D
from sympy.geometry.plane import Plane
from sympy.testing.pytest import raises
ae = lambda a, b, n: comp(a, b, 10**-n)
def test_refraction_angle():
n1, n2 = symbols('n1, n2')
m1 = Medium('m1')
m2 = Medium('m2')
r1 = Ray3D(Point3D(-1, -1, 1), Point3D(0, 0, 0))
i = Matrix([1, 1, 1])
n = Matrix([0, 0, 1])
normal_ray = Ray3D(Point3D(0, 0, 0), Point3D(0, 0, 1))
P = Plane(Point3D(0, 0, 0), normal_vector=[0, 0, 1])
assert refraction_angle(r1, 1, 1, n) == Matrix([[1], [1], [-1]])
assert refraction_angle([1, 1, 1], 1, 1, n) == Matrix([[1], [1], [-1]])
assert refraction_angle((1, 1, 1), 1, 1, n) == Matrix([[1], [1], [-1]])
assert refraction_angle(i, 1, 1, [0, 0, 1]) == Matrix([[1], [1], [-1]])
def test_evalf_product():
assert Product(n, (n, 1, 10)).evalf() == 3628800.
assert comp(Product(1 - S.Half**2/n**2, (n, 1, oo)).n(5), 0.63662)
assert Product(n, (n, -1, 3)).evalf() == 0
def N_equals(a, b):
"""Check whether two complex numbers are numerically close"""
return comp(a.n(), b.n(), 1.e-6)
