def _compute_normalization_constant(self, beta, n):
"""
Helper function for computing normalization
constant for joint probability density of eigen
values of Gaussian ensembles.
References
==========
.. [1] https://en.wikipedia.org/wiki/Selberg_integral#Mehta's_integral
"""
n = S(n)
prod_term = lambda j: gamma(1 + beta * S(j) / 2) / gamma(S.One + beta /
S(2))
j = Dummy('j', integer=True, positive=True)
term1 = Product(prod_term(j), (j, 1, n)).doit()
term2 = (2 / (beta * n))**(beta * n * (n - 1) / 4 + n / 2)
term3 = (2 * pi)**(n / 2)
return term1 * term2 * term3
def test_free_symbols():
for func in [Sum, Product]:
assert func(1, (x, 1, 2)).free_symbols == set()
assert func(0, (x, 1, y)).free_symbols == {y}
assert func(2, (x, 1, y)).free_symbols == {y}
assert func(x, (x, 1, 2)).free_symbols == set()
assert func(x, (x, 1, y)).free_symbols == {y}
assert func(x, (y, 1, y)).free_symbols == {x, y}
assert func(x, (y, 1, 2)).free_symbols == {x}
assert func(x, (y, 1, 1)).free_symbols == {x}
assert func(x, (y, 1, z)).free_symbols == {x, z}
assert func(x, (x, 1, y), (y, 1, 2)).free_symbols == set()
assert func(x, (x, 1, y), (y, 1, z)).free_symbols == {z}
assert func(x, (x, 1, y), (y, 1, y)).free_symbols == {y}
assert func(x, (y, 1, y), (y, 1, z)).free_symbols == {x, z}
assert Sum(1, (x, 1, y)).free_symbols == {y}
# free_symbols answers whether the object *as written* has free symbols,
# not whether the evaluated expression has free symbols
assert Product(1, (x, 1, y)).free_symbols == {y}
def test_MultivariateEwens():
from sympy.stats.joint_rv_types import MultivariateEwens
n, theta, i = symbols("n theta i", positive=True)
# tests for integer dimensions
theta_f = symbols("t_f", negative=True)
a = symbols("a_1:4", positive=True, integer=True)
ed = MultivariateEwens("E", 3, theta)
assert density(ed)(a[0], a[1], a[2]) == Piecewise(
(
6 * 2**(-a[1]) * 3**(-a[2]) * theta**a[0] * theta**a[1] *
theta**a[2] / (theta * (theta + 1) *
(theta + 2) * factorial(a[0]) * factorial(a[1]) *
factorial(a[2])),
Eq(a[0] + 2 * a[1] + 3 * a[2], 3),
),
(0, True),
)
assert marginal_distribution(ed, ed[1])(a[1]) == Piecewise(
(
6 * 2**(-a[1]) * theta**a[1] / ((theta + 1) *
(theta + 2) * factorial(a[1])),
Eq(2 * a[1] + 1, 3),
),
(0, True),
)
raises(ValueError, lambda: MultivariateEwens("e1", 5, theta_f))
# tests for symbolic dimensions
eds = MultivariateEwens("E", n, theta)
a = IndexedBase("a")
j, k = symbols("j, k")
den = Piecewise(
(
factorial(n) *
Product(theta**a[j] * (j + 1)**(-a[j]) / factorial(a[j]),
(j, 0, n - 1)) / RisingFactorial(theta, n),
Eq(n, Sum((k + 1) * a[k], (k, 0, n - 1))),
),
(0, True),
)
assert density(eds)(a).dummy_eq(den)
def pdf(self, *syms):
n, theta = self.n, self.theta
condi = isinstance(self.n, Integer)
if not (isinstance(syms[0], IndexedBase) or condi):
raise ValueError("Please use IndexedBase object for syms as "
"the dimension is symbolic")
term_1 = factorial(n) / rf(theta, n)
if condi:
term_2 = Mul.fromiter(theta**syms[j] /
((j + 1)**syms[j] * factorial(syms[j]))
for j in range(n))
cond = Eq(sum([(k + 1) * syms[k] for k in range(n)]), n)
return Piecewise((term_1 * term_2, cond), (0, True))
syms = syms[0]
j, k = symbols('j, k', positive=True, integer=True)
term_2 = Product(
theta**syms[j] / ((j + 1)**syms[j] * factorial(syms[j])),
(j, 0, n - 1))
cond = Eq(Sum((k + 1) * syms[k], (k, 0, n - 1)), n)
return Piecewise((term_1 * term_2, cond), (0, True))
def test_Wishart():
W = Wishart('W', 5, [[1, 0], [0, 1]])
assert W.pspace.distribution.set == MatrixSet(2, 2, S.Reals)
X = MatrixSymbol('X', 2, 2)
term1 = exp(Trace(Matrix([[-S(1)/2, 0], [0, -S(1)/2]])*X))
assert density(W)(X).doit() == term1 * Determinant(X)/(24*pi)
assert density(W)([[2, 1], [1, 2]]).doit() == exp(-2)/(8*pi)
n = symbols('n', positive=True)
d = symbols('d', positive=True, integer=True)
Y = MatrixSymbol('Y', d, d)
SM = MatrixSymbol('SM', d, d)
W = Wishart('W', n, SM)
k = Dummy('k')
exprd = 2**(-d*n/2)*pi**(-d*(d - 1)/4)*exp(Trace(-(S(1)/2)*SM**(-1)*Y)
)*Determinant(SM)**(-n/2)*Determinant(Y)**(
-d/2 + n/2 - S(1)/2)/Product(gamma(-k/2 + n/2 + S(1)/2), (k, 1, d))
assert density(W)(Y).dummy_eq(exprd)
raises(ValueError, lambda: density(W)(1))
raises(ValueError, lambda: Wishart('W', -1, [[1, 0], [0, 1]]))
raises(ValueError, lambda: Wishart('W', -1, [[1, 0], [2, 1]]))
raises(ValueError, lambda: Wishart('W', 2, [[1, 0], [0]]))
def test_GaussianUnitaryEnsemble():
H = RandomMatrixSymbol("H", 3, 3)
G = GUE("U", 3)
assert density(G)(H) == sqrt(2) * exp(
-3 * Trace(H**2) / 2) / (4 * pi**Rational(9, 2))
i, j = (
Dummy("i", integer=True, positive=True),
Dummy("j", integer=True, positive=True),
)
l = IndexedBase("l")
assert joint_eigen_distribution(G).dummy_eq(
Lambda(
(l[1], l[2], l[3]),
27 * sqrt(6) * exp(-3 * (l[1]**2) / 2 - 3 * (l[2]**2) / 2 - 3 *
(l[3]**2) / 2) *
Product(Abs(l[i] - l[j])**2, (j, i + 1, 3),
(i, 1, 2)) / (16 * pi**Rational(3, 2)),
))
s = Dummy("s")
assert level_spacing_distribution(G).dummy_eq(
Lambda(s, 32 * s**2 * exp(-4 * s**2 / pi) / pi**2))
def test_GaussianOrthogonalEnsemble():
H = RandomMatrixSymbol("H", 3, 3)
_H = MatrixSymbol("_H", 3, 3)
G = GOE("O", 3)
assert density(G)(H) == exp(-3 * Trace(H**2) / 4) / Integral(
exp(-3 * Trace(_H**2) / 4), _H)
i, j = (
Dummy("i", integer=True, positive=True),
Dummy("j", integer=True, positive=True),
)
l = IndexedBase("l")
assert joint_eigen_distribution(G).dummy_eq(
Lambda(
(l[1], l[2], l[3]),
9 * sqrt(2) *
exp(-3 * l[1]**2 / 2 - 3 * l[2]**2 / 2 - 3 * l[3]**2 / 2) *
Product(Abs(l[i] - l[j]), (j, i + 1, 3), (i, 1, 2)) / (32 * pi),
))
s = Dummy("s")
assert level_spacing_distribution(G).dummy_eq(
Lambda(s,
s * pi * exp(-(s**2) * pi / 4) / 2))
def test_GaussianSymplecticEnsemble():
H = RandomMatrixSymbol("H", 3, 3)
_H = MatrixSymbol("_H", 3, 3)
G = GSE("O", 3)
assert density(G)(H) == exp(-3 * Trace(H**2)) / Integral(
exp(-3 * Trace(_H**2)), _H)
i, j = (
Dummy("i", integer=True, positive=True),
Dummy("j", integer=True, positive=True),
)
l = IndexedBase("l")
assert joint_eigen_distribution(G).dummy_eq(
Lambda(
(l[1], l[2], l[3]),
162 * sqrt(3) *
exp(-3 * l[1]**2 / 2 - 3 * l[2]**2 / 2 - 3 * l[3]**2 / 2) *
Product(Abs(l[i] - l[j])**4, (j, i + 1, 3),
(i, 1, 2)) / (5 * pi**Rational(3, 2)),
))
s = Dummy("s")
assert level_spacing_distribution(G).dummy_eq(
Lambda(s,
S(262144) * s**4 * exp(-64 * s**2 / (9 * pi)) / (729 * pi**3)))
def test_simple_products():
assert product(2, (k, a, n)) == 2**(n - a + 1)
assert product(k, (k, 1, n)) == factorial(n)
assert product(k**3, (k, 1, n)) == factorial(n)**3
assert product(k + 1, (k, 0, n - 1)) == factorial(n)
assert product(k + 1, (k, a, n - 1)) == rf(1 + a, n - a)
assert product(cos(k),
(k, 0, 5)) == cos(1) * cos(2) * cos(3) * cos(4) * cos(5)
assert product(cos(k), (k, 3, 5)) == cos(3) * cos(4) * cos(5)
assert product(cos(k), (k, 1, Rational(5, 2))) != cos(1) * cos(2)
assert isinstance(product(k**k, (k, 1, n)), Product)
assert Product(x**k, (k, 1, n)).variables == [k]
raises(ValueError, lambda: Product(n))
raises(ValueError, lambda: Product(n, k))
raises(ValueError, lambda: Product(n, k, 1))
raises(ValueError, lambda: Product(n, k, 1, 10))
raises(ValueError, lambda: Product(n, (k, 1)))
def test_indexed_idx_sum():
i = symbols('i', cls=Idx)
r = Indexed('r', i)
assert Sum(r, (i, 0, 3)).doit() == sum([r.xreplace({i: j}) for j in range(4)])
assert Product(r, (i, 0, 3)).doit() == prod([r.xreplace({i: j}) for j in range(4)])
j = symbols('j', integer=True)
assert Sum(r, (i, j, j+2)).doit() == sum([r.xreplace({i: j+k}) for k in range(3)])
assert Product(r, (i, j, j+2)).doit() == prod([r.xreplace({i: j+k}) for k in range(3)])
k = Idx('k', range=(1, 3))
A = IndexedBase('A')
assert Sum(A[k], k).doit() == sum([A[Idx(j, (1, 3))] for j in range(1, 4)])
assert Product(A[k], k).doit() == prod([A[Idx(j, (1, 3))] for j in range(1, 4)])
raises(ValueError, lambda: Sum(A[k], (k, 1, 4)))
raises(ValueError, lambda: Sum(A[k], (k, 0, 3)))
raises(ValueError, lambda: Sum(A[k], (k, 2, oo)))
raises(ValueError, lambda: Product(A[k], (k, 1, 4)))
raises(ValueError, lambda: Product(A[k], (k, 0, 3)))
raises(ValueError, lambda: Product(A[k], (k, 2, oo)))
def test_karr_convention():
# Test the Karr product convention that we want to hold.
# See his paper "Summation in Finite Terms" for a detailed
# reasoning why we really want exactly this definition.
# The convention is described for sums on page 309 and
# essentially in section 1.4, definition 3. For products
# we can find in analogy:
#
# \prod_{m <= i < n} f(i) 'has the obvious meaning' for m < n
# \prod_{m <= i < n} f(i) = 0 for m = n
# \prod_{m <= i < n} f(i) = 1 / \prod_{n <= i < m} f(i) for m > n
#
# It is important to note that he defines all products with
# the upper limit being *exclusive*.
# In contrast, sympy and the usual mathematical notation has:
#
# prod_{i = a}^b f(i) = f(a) * f(a+1) * ... * f(b-1) * f(b)
#
# with the upper limit *inclusive*. So translating between
# the two we find that:
#
# \prod_{m <= i < n} f(i) = \prod_{i = m}^{n-1} f(i)
#
# where we intentionally used two different ways to typeset the
# products and its limits.
i = Symbol("i", integer=True)
k = Symbol("k", integer=True)
j = Symbol("j", integer=True)
# A simple example with a concrete factors and symbolic limits.
# The normal product: m = k and n = k + j and therefore m < n:
m = k
n = k + j
a = m
b = n - 1
S1 = Product(i**2, (i, a, b)).doit()
# The reversed product: m = k + j and n = k and therefore m > n:
m = k + j
n = k
a = m
b = n - 1
S2 = Product(i**2, (i, a, b)).doit()
assert simplify(S1 * S2) == 1
# Test the empty product: m = k and n = k and therefore m = n:
m = k
n = k
a = m
b = n - 1
Sz = Product(i**2, (i, a, b)).doit()
assert Sz == 1
# Another example this time with an unspecified factor and
# numeric limits. (We can not do both tests in the same example.)
f = Function("f")
# The normal product with m < n:
m = 2
n = 11
a = m
b = n - 1
S1 = Product(f(i), (i, a, b)).doit()
# The reversed product with m > n:
m = 11
n = 2
a = m
b = n - 1
S2 = Product(f(i), (i, a, b)).doit()
assert simplify(S1 * S2) == 1
# Test the empty product with m = n:
m = 5
n = 5
a = m
b = n - 1
Sz = Product(f(i), (i, a, b)).doit()
assert Sz == 1
def test_evalf_product():
assert Product(n, (n, 1, 10)).evalf() == 3628800.
assert Product(1 - S.Half**2 / n**2, (n, 1, oo)).evalf(5) == 0.63662
assert Product(n, (n, -1, 3)).evalf() == 0
def test_infinite_product():
# Issue 2638
assert isinstance(Product(2**(1 / factorial(n)), (n, 0, oo)), Product)
def test_KroneckerDelta_Product():
y = Symbol('y')
assert Product(x*KroneckerDelta(x, y), (x, 0, 1)).doit() == 0
class TestAllGood(object):
# These latex strings should parse to the corresponding SymPy expression
GOOD_PAIRS = [
("0", Rational(0)),
("1", Rational(1)),
("-3.14", Rational(-314, 100)),
("5-3", _Add(5, _Mul(-1, 3))),
("(-7.13)(1.5)", _Mul(Rational('-7.13'), Rational('1.5'))),
("\\left(-7.13\\right)\\left(1.5\\right)", _Mul(Rational('-7.13'), Rational('1.5'))),
("x", x),
("2x", 2 * x),
("x^2", x**2),
("x^{3 + 1}", x**_Add(3, 1)),
("x^{\\left\\{3 + 1\\right\\}}", x**_Add(3, 1)),
("-3y + 2x", _Add(_Mul(2, x), Mul(-1, 3, y, evaluate=False))),
("-c", -c),
("a \\cdot b", a * b),
("a / b", a / b),
("a \\div b", a / b),
("a + b", a + b),
("a + b - a", Add(a, b, _Mul(-1, a), evaluate=False)),
("a^2 + b^2 = c^2", Eq(a**2 + b**2, c**2)),
("a^2 + b^2 != 2c^2", Ne(a**2 + b**2, 2 * c**2)),
("a\\mod b", Mod(a, b)),
("\\sin \\theta", sin(theta)),
("\\sin(\\theta)", sin(theta)),
("\\sin\\left(\\theta\\right)", sin(theta)),
("\\sin^{-1} a", asin(a)),
("\\sin a \\cos b", _Mul(sin(a), cos(b))),
("\\sin \\cos \\theta", sin(cos(theta))),
("\\sin(\\cos \\theta)", sin(cos(theta))),
("\\arcsin(a)", asin(a)),
("\\arccos(a)", acos(a)),
("\\arctan(a)", atan(a)),
("\\sinh(a)", sinh(a)),
("\\cosh(a)", cosh(a)),
("\\tanh(a)", tanh(a)),
("\\sinh^{-1}(a)", asinh(a)),
("\\cosh^{-1}(a)", acosh(a)),
("\\tanh^{-1}(a)", atanh(a)),
("\\arcsinh(a)", asinh(a)),
("\\arccosh(a)", acosh(a)),
("\\arctanh(a)", atanh(a)),
("\\arsinh(a)", asinh(a)),
("\\arcosh(a)", acosh(a)),
("\\artanh(a)", atanh(a)),
("\\operatorname{arcsinh}(a)", asinh(a)),
("\\operatorname{arccosh}(a)", acosh(a)),
("\\operatorname{arctanh}(a)", atanh(a)),
("\\operatorname{arsinh}(a)", asinh(a)),
("\\operatorname{arcosh}(a)", acosh(a)),
("\\operatorname{artanh}(a)", atanh(a)),
("\\operatorname{gcd}(a, b)", UnevaluatedExpr(gcd(a, b))),
("\\operatorname{lcm}(a, b)", UnevaluatedExpr(lcm(a, b))),
("\\operatorname{gcd}(a,b)", UnevaluatedExpr(gcd(a, b))),
("\\operatorname{lcm}(a,b)", UnevaluatedExpr(lcm(a, b))),
("\\operatorname{floor}(a)", floor(a)),
("\\operatorname{ceil}(b)", ceiling(b)),
("\\cos^2(x)", cos(x)**2),
("\\cos(x)^2", cos(x)**2),
("\\gcd(a, b)", UnevaluatedExpr(gcd(a, b))),
("\\lcm(a, b)", UnevaluatedExpr(lcm(a, b))),
("\\gcd(a,b)", UnevaluatedExpr(gcd(a, b))),
("\\lcm(a,b)", UnevaluatedExpr(lcm(a, b))),
("\\floor(a)", floor(a)),
("\\ceil(b)", ceiling(b)),
("\\max(a, b)", Max(a, b)),
("\\min(a, b)", Min(a, b)),
("\\frac{a}{b}", a / b),
("\\frac{a + b}{c}", _Mul(a + b, _Pow(c, -1))),
("\\frac{7}{3}", Rational(7, 3)),
("(\\csc x)(\\sec y)", csc(x) * sec(y)),
("\\lim_{x \\to 3} a", Limit(a, x, 3)),
("\\lim_{x \\rightarrow 3} a", Limit(a, x, 3)),
("\\lim_{x \\Rightarrow 3} a", Limit(a, x, 3)),
("\\lim_{x \\longrightarrow 3} a", Limit(a, x, 3)),
("\\lim_{x \\Longrightarrow 3} a", Limit(a, x, 3)),
("\\lim_{x \\to 3^{+}} a", Limit(a, x, 3, dir='+')),
("\\lim_{x \\to 3^{-}} a", Limit(a, x, 3, dir='-')),
("\\infty", oo),
("\\infty\\%", oo),
("\\$\\infty", oo),
("-\\infty", -oo),
("-\\infty\\%", -oo),
("-\\$\\infty", -oo),
("\\lim_{x \\to \\infty} \\frac{1}{x}", Limit(_Mul(1, _Pow(x, -1)), x, oo)),
("\\frac{d}{dx} x", Derivative(x, x)),
("\\frac{d}{dt} x", Derivative(x, t)),
# ("f(x)", f(x)),
# ("f(x, y)", f(x, y)),
# ("f(x, y, z)", f(x, y, z)),
# ("\\frac{d f(x)}{dx}", Derivative(f(x), x)),
# ("\\frac{d\\theta(x)}{dx}", Derivative(theta(x), x)),
("|x|", _Abs(x)),
("\\left|x\\right|", _Abs(x)),
("||x||", _Abs(_Abs(x))),
("|x||y|", _Abs(x) * _Abs(y)),
("||x||y||", _Abs(_Abs(x) * _Abs(y))),
("\\lfloor x\\rfloor", floor(x)),
("\\lceil y\\rceil", ceiling(y)),
("\\pi^{|xy|}", pi**_Abs(x * y)),
("\\frac{\\pi}{3}", _Mul(pi, _Pow(3, -1))),
("\\sin{\\frac{\\pi}{2}}", sin(_Mul(pi, _Pow(2, -1)), evaluate=False)),
("a+bI", a + I * b),
("e^{I\\pi}", Integer(-1)),
("\\int x dx", Integral(x, x)),
("\\int x d\\theta", Integral(x, theta)),
("\\int (x^2 - y)dx", Integral(x**2 - y, x)),
("\\int x + a dx", Integral(_Add(x, a), x)),
("\\int da", Integral(1, a)),
("\\int_0^7 dx", Integral(1, (x, 0, 7))),
("\\int_a^b x dx", Integral(x, (x, a, b))),
("\\int^b_a x dx", Integral(x, (x, a, b))),
("\\int_{a}^b x dx", Integral(x, (x, a, b))),
("\\int^{b}_a x dx", Integral(x, (x, a, b))),
("\\int_{a}^{b} x dx", Integral(x, (x, a, b))),
("\\int_{ }^{}x dx", Integral(x, x)),
("\\int^{ }_{ }x dx", Integral(x, x)),
("\\int^{b}_{a} x dx", Integral(x, (x, a, b))),
# ("\\int_{f(a)}^{f(b)} f(z) dz", Integral(f(z), (z, f(a), f(b)))),
("\\int (x+a)", Integral(_Add(x, a), x)),
("\\int a + b + c dx", Integral(Add(a, b, c, evaluate=False), x)),
("\\int \\frac{dz}{z}", Integral(Pow(z, -1), z)),
("\\int \\frac{3 dz}{z}", Integral(3 * Pow(z, -1), z)),
("\\int \\frac{1}{x} dx", Integral(Pow(x, -1), x)),
("\\int \\frac{1}{a} + \\frac{1}{b} dx", Integral(_Add(_Pow(a, -1), Pow(b, -1)), x)),
("\\int \\frac{3 \\cdot d\\theta}{\\theta}", Integral(3 * _Pow(theta, -1), theta)),
("\\int \\frac{1}{x} + 1 dx", Integral(_Add(_Pow(x, -1), 1), x)),
("x_0", Symbol('x_0', real=True, positive=True)),
("x_{1}", Symbol('x_1', real=True, positive=True)),
("x_a", Symbol('x_a', real=True, positive=True)),
("x_{b}", Symbol('x_b', real=True, positive=True)),
("h_\\theta", Symbol('h_{\\theta}', real=True, positive=True)),
("h_\\theta ", Symbol('h_{\\theta}', real=True, positive=True)),
("h_{\\theta}", Symbol('h_{\\theta}', real=True, positive=True)),
# ("h_{\\theta}(x_0, x_1)", Symbol('h_{theta}', real=True)(Symbol('x_{0}', real=True), Symbol('x_{1}', real=True))),
("x!", _factorial(x)),
("100!", _factorial(100)),
("\\theta!", _factorial(theta)),
("(x + 1)!", _factorial(_Add(x, 1))),
("\\left(x + 1\\right)!", _factorial(_Add(x, 1))),
("(x!)!", _factorial(_factorial(x))),
("x!!!", _factorial(_factorial(_factorial(x)))),
("5!7!", _Mul(_factorial(5), _factorial(7))),
("\\sqrt{x}", sqrt(x)),
("\\sqrt{x + b}", sqrt(_Add(x, b))),
("\\sqrt[3]{\\sin x}", root(sin(x), 3)),
("\\sqrt[y]{\\sin x}", root(sin(x), y)),
("\\sqrt[\\theta]{\\sin x}", root(sin(x), theta)),
("x < y", StrictLessThan(x, y)),
("x \\leq y", LessThan(x, y)),
("x > y", StrictGreaterThan(x, y)),
("x \\geq y", GreaterThan(x, y)),
("\\sum_{k = 1}^{3} c", Sum(c, (k, 1, 3))),
("\\sum_{k = 1}^3 c", Sum(c, (k, 1, 3))),
("\\sum^{3}_{k = 1} c", Sum(c, (k, 1, 3))),
("\\sum^3_{k = 1} c", Sum(c, (k, 1, 3))),
("\\sum_{k = 1}^{10} k^2", Sum(k**2, (k, 1, 10))),
("\\sum_{n = 0}^{\\infty} \\frac{1}{n!}", Sum(_Pow(_factorial(n), -1), (n, 0, oo))),
("\\prod_{a = b}^{c} x", Product(x, (a, b, c))),
("\\prod_{a = b}^c x", Product(x, (a, b, c))),
("\\prod^{c}_{a = b} x", Product(x, (a, b, c))),
("\\prod^c_{a = b} x", Product(x, (a, b, c))),
("\\ln x", _log(x, E)),
("\\ln xy", _log(x * y, E)),
("\\log x", _log(x, 10)),
("\\log xy", _log(x * y, 10)),
# ("\\log_2 x", _log(x, 2)),
("\\log_{2} x", _log(x, 2)),
# ("\\log_a x", _log(x, a)),
("\\log_{a} x", _log(x, a)),
("\\log_{11} x", _log(x, 11)),
("\\log_{a^2} x", _log(x, _Pow(a, 2))),
("[x]", x),
("[a + b]", _Add(a, b)),
("\\frac{d}{dx} [ \\tan x ]", Derivative(tan(x), x)),
("2\\overline{x}", 2 * Symbol('xbar', real=True, positive=True)),
("2\\overline{x}_n", 2 * Symbol('xbar_n', real=True, positive=True)),
("\\frac{x}{\\overline{x}_n}", x / Symbol('xbar_n', real=True, positive=True)),
("\\frac{\\sin(x)}{\\overline{x}_n}", sin(x) / Symbol('xbar_n', real=True, positive=True)),
("2\\bar{x}", 2 * Symbol('xbar', real=True, positive=True)),
("2\\bar{x}_n", 2 * Symbol('xbar_n', real=True, positive=True)),
("\\sin\\left(\\theta\\right) \\cdot4", sin(theta) * 4),
("\\ln\\left(\\theta\\right)", _log(theta, E)),
("\\ln\\left(x-\\theta\\right)", _log(x - theta, E)),
("\\ln\\left(\\left(x-\\theta\\right)\\right)", _log(x - theta, E)),
("\\ln\\left(\\left[x-\\theta\\right]\\right)", _log(x - theta, E)),
("\\ln\\left(\\left\\{x-\\theta\\right\\}\\right)", _log(x - theta, E)),
("\\ln\\left(\\left|x-\\theta\\right|\\right)", _log(_Abs(x - theta), E)),
("\\frac{1}{2}xy(x+y)", Mul(Rational(1, 2), x, y, (x + y), evaluate=False)),
("\\frac{1}{2}\\theta(x+y)", Mul(Rational(1, 2), theta, (x + y), evaluate=False)),
("1-f(x)", 1 - f * x),
("\\begin{matrix}1&2\\\\3&4\\end{matrix}", Matrix([[1, 2], [3, 4]])),
("\\begin{matrix}x&x^2\\\\\\sqrt{x}&x\\end{matrix}", Matrix([[x, x**2], [_Pow(x, S.Half), x]])),
("\\begin{matrix}\\sqrt{x}\\\\\\sin(\\theta)\\end{matrix}", Matrix([_Pow(x, S.Half), sin(theta)])),
("\\begin{pmatrix}1&2\\\\3&4\\end{pmatrix}", Matrix([[1, 2], [3, 4]])),
("\\begin{bmatrix}1&2\\\\3&4\\end{bmatrix}", Matrix([[1, 2], [3, 4]])),
# scientific notation
("2.5\\times 10^2", Rational(250)),
("1,500\\times 10^{-1}", Rational(150)),
# e notation
("2.5E2", Rational(250)),
("1,500E-1", Rational(150)),
# multiplication without cmd
("2x2y", Mul(2, x, 2, y, evaluate=False)),
("2x2", Mul(2, x, 2, evaluate=False)),
("x2", x * 2),
# lin alg processing
("\\theta\\begin{matrix}1&2\\\\3&4\\end{matrix}", MatMul(theta, Matrix([[1, 2], [3, 4]]), evaluate=False)),
("\\theta\\begin{matrix}1\\\\3\\end{matrix} - \\begin{matrix}-1\\\\2\\end{matrix}", MatAdd(MatMul(theta, Matrix([[1], [3]]), evaluate=False), MatMul(-1, Matrix([[-1], [2]]), evaluate=False), evaluate=False)),
("\\theta\\begin{matrix}1&0\\\\0&1\\end{matrix}*\\begin{matrix}3\\\\-2\\end{matrix}", MatMul(theta, Matrix([[1, 0], [0, 1]]), Matrix([3, -2]), evaluate=False)),
("\\frac{1}{9}\\theta\\begin{matrix}1&2\\\\3&4\\end{matrix}", MatMul(Rational(1, 9), theta, Matrix([[1, 2], [3, 4]]), evaluate=False)),
("\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix},\\begin{pmatrix}4\\\\3\\\\1\\end{pmatrix}", [Matrix([1, 2, 3]), Matrix([4, 3, 1])]),
("\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix};\\begin{pmatrix}4\\\\3\\\\1\\end{pmatrix}", [Matrix([1, 2, 3]), Matrix([4, 3, 1])]),
("\\left\\{\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix},\\begin{pmatrix}4\\\\3\\\\1\\end{pmatrix}\\right\\}", [Matrix([1, 2, 3]), Matrix([4, 3, 1])]),
("\\left\\{\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix},\\begin{pmatrix}4\\\\3\\\\1\\end{pmatrix},\\begin{pmatrix}1\\\\1\\\\1\\end{pmatrix}\\right\\}", [Matrix([1, 2, 3]), Matrix([4, 3, 1]), Matrix([1, 1, 1])]),
("\\left\\{\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix}\\right\\}", Matrix([1, 2, 3])),
("\\left{\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix}\\right}", Matrix([1, 2, 3])),
("{\\begin{pmatrix}1\\\\2\\\\3\\end{pmatrix}}", Matrix([1, 2, 3])),
# us dollars
("\\$1,000.00", Rational(1000)),
("\\$543.21", Rational(54321, 100)),
("\\$0.009", Rational(9, 1000)),
# percentages
("100\\%", Rational(1)),
("1.5\\%", Rational(15, 1000)),
("0.05\\%", Rational(5, 10000)),
# empty set
("\\emptyset", S.EmptySet),
# divide by zero
("\\frac{1}{0}", _Pow(0, -1)),
("1+\\frac{5}{0}", _Add(1, _Mul(5, _Pow(0, -1)))),
# adjacent single char sub sup
("4^26^2", _Mul(_Pow(4, 2), _Pow(6, 2))),
("x_22^2", _Mul(Symbol('x_2', real=True, positive=True), _Pow(2, 2)))
]
def test_good_pair(self, s, eq):
assert_equal(s, eq)
def test_issue_13546():
n = Symbol('n')
k = Symbol('k')
p = Product(n + 1 / 2**k, (k, 0, n-1)).doit()
assert p.subs(n, 2).doit() == Rational(15, 2)
def test_rewrite_Sum():
assert Product(1 - S.Half**2/k**2, (k, 1, oo)).rewrite(Sum) == \
exp(Sum(log(1 - 1/(4*k**2)), (k, 1, oo)))
def test_reverse_order():
x, y, a, b, c, d= symbols('x, y, a, b, c, d', integer = True)
assert Product(x, (x, 0, 3)).reverse_order(0) == Product(1/x, (x, 4, -1))
assert Product(x*y, (x, 1, 5), (y, 0, 6)).reverse_order(0, 1) == \
Product(x*y, (x, 6, 0), (y, 7, -1))
assert Product(x, (x, 1, 2)).reverse_order(0) == Product(1/x, (x, 3, 0))
assert Product(x, (x, 1, 3)).reverse_order(0) == Product(1/x, (x, 4, 0))
assert Product(x, (x, 1, a)).reverse_order(0) == Product(1/x, (x, a + 1, 0))
assert Product(x, (x, a, 5)).reverse_order(0) == Product(1/x, (x, 6, a - 1))
assert Product(x, (x, a + 1, a + 5)).reverse_order(0) == \
Product(1/x, (x, a + 6, a))
assert Product(x, (x, a + 1, a + 2)).reverse_order(0) == \
Product(1/x, (x, a + 3, a))
assert Product(x, (x, a + 1, a + 1)).reverse_order(0) == \
Product(1/x, (x, a + 2, a))
assert Product(x, (x, a, b)).reverse_order(0) == Product(1/x, (x, b + 1, a - 1))
assert Product(x, (x, a, b)).reverse_order(x) == Product(1/x, (x, b + 1, a - 1))
assert Product(x*y, (x, a, b), (y, 2, 5)).reverse_order(x, 1) == \
Product(x*y, (x, b + 1, a - 1), (y, 6, 1))
assert Product(x*y, (x, a, b), (y, 2, 5)).reverse_order(y, x) == \
Product(x*y, (x, b + 1, a - 1), (y, 6, 1))
def test_issue_9983():
n = Symbol('n', integer=True, positive=True)
p = Product(1 + 1/n**Rational(2, 3), (n, 1, oo))
assert p.is_convergent() is S.false
assert product(1 + 1/n**Rational(2, 3), (n, 1, oo)) == p.doit()
def test_simplify():
y, t, b, c = symbols('y, t, b, c', integer=True)
assert simplify(Product(x*y, (x, n, m), (y, a, k)) * \
Product(y, (x, n, m), (y, a, k))) == \
Product(x*y**2, (x, n, m), (y, a, k))
assert simplify(3 * y* Product(x, (x, n, m)) * Product(x, (x, m + 1, a))) \
== 3 * y * Product(x, (x, n, a))
assert simplify(Product(x, (x, k + 1, a)) * Product(x, (x, n, k))) == \
Product(x, (x, n, a))
assert simplify(Product(x, (x, k + 1, a)) * Product(x + 1, (x, n, k))) == \
Product(x, (x, k + 1, a)) * Product(x + 1, (x, n, k))
assert simplify(Product(x, (t, a, b)) * Product(y, (t, a, b)) * \
Product(x, (t, b+1, c))) == Product(x*y, (t, a, b)) * \
Product(x, (t, b+1, c))
assert simplify(Product(x, (t, a, b)) * Product(x, (t, b+1, c)) * \
Product(y, (t, a, b))) == Product(x*y, (t, a, b)) * \
Product(x, (t, b+1, c))
def test_Product_is_convergent():
assert Product(1/n**2, (n, 1, oo)).is_convergent() is S.false
assert Product(exp(1/n**2), (n, 1, oo)).is_convergent() is S.true
assert Product(1/n, (n, 1, oo)).is_convergent() is S.false
assert Product(1 + 1/n, (n, 1, oo)).is_convergent() is S.false
assert Product(1 + 1/n**2, (n, 1, oo)).is_convergent() is S.true
def test_distribution_over_equality():
assert Product(Eq(x * 2, f(x)),
(x, 1, 3)).doit() == Eq(48,
f(1) * f(2) * f(3))
assert Sum(Eq(f(x), x**2), (x, 0, y)) == \
Eq(Sum(f(x), (x, 0, y)), Sum(x**2, (x, 0, y)))
def test_simple_products():
assert Product(S.NaN, (x, 1, 3)) is S.NaN
assert product(S.NaN, (x, 1, 3)) is S.NaN
assert Product(x, (n, a, a)).doit() == x
assert Product(x, (x, a, a)).doit() == a
assert Product(x, (y, 1, a)).doit() == x**a
lo, hi = 1, 2
s1 = Product(n, (n, lo, hi))
s2 = Product(n, (n, hi, lo))
assert s1 != s2
# This IS correct according to Karr product convention
assert s1.doit() == 2
assert s2.doit() == 1
lo, hi = x, x + 1
s1 = Product(n, (n, lo, hi))
s2 = Product(n, (n, hi, lo))
s3 = 1 / Product(n, (n, hi + 1, lo - 1))
assert s1 != s2
# This IS correct according to Karr product convention
assert s1.doit() == x * (x + 1)
assert s2.doit() == 1
assert s3.doit() == x * (x + 1)
assert Product(Integral(2*x, (x, 1, y)) + 2*x, (x, 1, 2)).doit() == \
(y**2 + 1)*(y**2 + 3)
assert product(2, (n, a, b)) == 2**(b - a + 1)
assert product(n, (n, 1, b)) == factorial(b)
assert product(n**3, (n, 1, b)) == factorial(b)**3
assert product(3**(2 + n), (n, a, b)) \
== 3**(2*(1 - a + b) + b/2 + (b**2)/2 + a/2 - (a**2)/2)
assert product(cos(n), (n, 3, 5)) == cos(3) * cos(4) * cos(5)
assert product(cos(n), (n, x, x + 2)) == cos(x) * cos(x + 1) * cos(x + 2)
assert isinstance(product(cos(n), (n, x, x + S.Half)), Product)
# If Product managed to evaluate this one, it most likely got it wrong!
assert isinstance(Product(n**n, (n, 1, b)), Product)
("\\sqrt[y]{\\sin x}", root(sin(x), y)),
("\\sqrt[\\theta]{\\sin x}", root(sin(x), theta)),
("x < y", StrictLessThan(x, y)), ("x \\leq y", LessThan(x, y)),
("x > y", StrictGreaterThan(x, y)),
("x \\geq y", GreaterThan(x, y)), ("\\mathit{x}", Symbol('x')),
("\\mathit{test}", Symbol('test')),
("\\mathit{TEST}", Symbol('TEST')),
("\\mathit{HELLO world}", Symbol('HELLO world')),
("\\sum_{k = 1}^{3} c", Sum(c, (k, 1, 3))),
("\\sum_{k = 1}^3 c", Sum(c, (k, 1, 3))),
("\\sum^{3}_{k = 1} c", Sum(c, (k, 1, 3))),
("\\sum^3_{k = 1} c", Sum(c, (k, 1, 3))),
("\\sum_{k = 1}^{10} k^2", Sum(k**2, (k, 1, 10))),
("\\sum_{n = 0}^{\\infty} \\frac{1}{n!}",
Sum(_Pow(_factorial(n), -1), (n, 0, oo))),
("\\prod_{a = b}^{c} x", Product(x, (a, b, c))),
("\\prod_{a = b}^c x", Product(x, (a, b, c))),
("\\prod^{c}_{a = b} x", Product(x, (a, b, c))),
("\\prod^c_{a = b} x", Product(x, (a, b, c))),
("\\ln x", _log(x, E)), ("\\ln xy", _log(x * y, E)),
("\\log x", _log(x, 10)), ("\\log xy", _log(x * y, 10)),
("\\log_{2} x", _log(x, 2)), ("\\log_{a} x", _log(x, a)),
("\\log_{11} x", _log(x, 11)),
("\\log_{a^2} x", _log(x, _Pow(a, 2))), ("[x]", x),
("[a + b]", _Add(a, b)),
("\\frac{d}{dx} [ \\tan x ]", Derivative(tan(x), x))]
def test_parseable():
from sympy.parsing.latex import parse_latex
for latex_str, sympy_expr in GOOD_PAIRS:
def test_exp_summation():
w = symbols("w")
m, n, i, j = symbols("m n i j")
expr = exp(Sum(w * i, (i, 0, n), (j, 0, m)))
assert expr.expand() == Product(exp(w * i), (i, 0, n), (j, 0, m))
def _eval_rewrite_as_Product(self, n):
from sympy import Product
if not (n.is_integer and n.is_nonnegative):
return self
k = Dummy('k', integer=True, positive=True)
return Product((n + k) / k, (k, 2, n))
def test_Product_doit():
assert Product(n * Integral(a**2), (n, 1, 3)).doit() == 2 * a**9 / 9
assert Product(n*Integral(a**2), (n, 1, 3)).doit(deep=False) == \
6*Integral(a**2)**3
assert product(n * Integral(a**2), (n, 1, 3)) == 6 * Integral(a**2)**3
def test_simplify_prod():
y, t, b, c = symbols('y, t, b, c', integer = True)
_simplify = lambda e: simplify(e, doit=False)
assert _simplify(Product(x*y, (x, n, m), (y, a, k)) * \
Product(y, (x, n, m), (y, a, k))) == \
Product(x*y**2, (x, n, m), (y, a, k))
assert _simplify(3 * y* Product(x, (x, n, m)) * Product(x, (x, m + 1, a))) \
== 3 * y * Product(x, (x, n, a))
assert _simplify(Product(x, (x, k + 1, a)) * Product(x, (x, n, k))) == \
Product(x, (x, n, a))
assert _simplify(Product(x, (x, k + 1, a)) * Product(x + 1, (x, n, k))) == \
Product(x, (x, k + 1, a)) * Product(x + 1, (x, n, k))
assert _simplify(Product(x, (t, a, b)) * Product(y, (t, a, b)) * \
Product(x, (t, b+1, c))) == Product(x*y, (t, a, b)) * \
Product(x, (t, b+1, c))
assert _simplify(Product(x, (t, a, b)) * Product(x, (t, b+1, c)) * \
Product(y, (t, a, b))) == Product(x*y, (t, a, b)) * \
Product(x, (t, b+1, c))
def _eval_rewrite_as_Product(self, n, **kwargs):
from sympy import Product
if n.is_nonnegative and n.is_integer:
i = Dummy('i', integer=True)
return Product(i, (i, 1, n))
def test_reorder():
b, y, c, d, z = symbols('b, y, c, d, z', integer = True)
assert Product(x*y, (x, a, b), (y, c, d)).reorder((0, 1)) == \
Product(x*y, (y, c, d), (x, a, b))
assert Product(x, (x, a, b), (x, c, d)).reorder((0, 1)) == \
Product(x, (x, c, d), (x, a, b))
assert Product(x*y + z, (x, a, b), (z, m, n), (y, c, d)).reorder(\
(2, 0), (0, 1)) == Product(x*y + z, (z, m, n), (y, c, d), (x, a, b))
assert Product(x*y*z, (x, a, b), (y, c, d), (z, m, n)).reorder(\
(0, 1), (1, 2), (0, 2)) == \
Product(x*y*z, (x, a, b), (z, m, n), (y, c, d))
assert Product(x*y*z, (x, a, b), (y, c, d), (z, m, n)).reorder(\
(x, y), (y, z), (x, z)) == \
Product(x*y*z, (x, a, b), (z, m, n), (y, c, d))
assert Product(x*y, (x, a, b), (y, c, d)).reorder((x, 1)) == \
Product(x*y, (y, c, d), (x, a, b))
assert Product(x*y, (x, a, b), (y, c, d)).reorder((y, x)) == \
Product(x*y, (y, c, d), (x, a, b))
