642 lines
21 KiB
Python
642 lines
21 KiB
Python
"""Tests for the implementation of RootOf class and related tools. """
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from sympy.polys.polytools import Poly
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import sympy.polys.rootoftools as rootoftools
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from sympy.polys.rootoftools import (rootof, RootOf, CRootOf, RootSum,
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_pure_key_dict as D)
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from sympy.polys.polyerrors import (
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MultivariatePolynomialError,
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GeneratorsNeeded,
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PolynomialError,
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)
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from sympy.core.function import (Function, Lambda)
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from sympy.core.numbers import (Float, I, Rational)
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from sympy.core.relational import Eq
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from sympy.core.singleton import S
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from sympy.functions.elementary.exponential import (exp, log)
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from sympy.functions.elementary.miscellaneous import sqrt
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from sympy.functions.elementary.trigonometric import tan
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from sympy.integrals.integrals import Integral
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from sympy.polys.orthopolys import legendre_poly
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from sympy.solvers.solvers import solve
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from sympy.testing.pytest import raises, slow
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from sympy.core.expr import unchanged
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from sympy.abc import a, b, x, y, z, r
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def test_CRootOf___new__():
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assert rootof(x, 0) == 0
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assert rootof(x, -1) == 0
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assert rootof(x, S.Zero) == 0
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assert rootof(x - 1, 0) == 1
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assert rootof(x - 1, -1) == 1
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assert rootof(x + 1, 0) == -1
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assert rootof(x + 1, -1) == -1
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assert rootof(x**2 + 2*x + 3, 0) == -1 - I*sqrt(2)
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assert rootof(x**2 + 2*x + 3, 1) == -1 + I*sqrt(2)
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assert rootof(x**2 + 2*x + 3, -1) == -1 + I*sqrt(2)
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assert rootof(x**2 + 2*x + 3, -2) == -1 - I*sqrt(2)
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r = rootof(x**2 + 2*x + 3, 0, radicals=False)
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assert isinstance(r, RootOf) is True
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r = rootof(x**2 + 2*x + 3, 1, radicals=False)
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assert isinstance(r, RootOf) is True
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r = rootof(x**2 + 2*x + 3, -1, radicals=False)
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assert isinstance(r, RootOf) is True
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r = rootof(x**2 + 2*x + 3, -2, radicals=False)
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assert isinstance(r, RootOf) is True
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assert rootof((x - 1)*(x + 1), 0, radicals=False) == -1
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assert rootof((x - 1)*(x + 1), 1, radicals=False) == 1
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assert rootof((x - 1)*(x + 1), -1, radicals=False) == 1
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assert rootof((x - 1)*(x + 1), -2, radicals=False) == -1
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assert rootof((x - 1)*(x + 1), 0, radicals=True) == -1
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assert rootof((x - 1)*(x + 1), 1, radicals=True) == 1
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assert rootof((x - 1)*(x + 1), -1, radicals=True) == 1
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assert rootof((x - 1)*(x + 1), -2, radicals=True) == -1
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assert rootof((x - 1)*(x**3 + x + 3), 0) == rootof(x**3 + x + 3, 0)
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assert rootof((x - 1)*(x**3 + x + 3), 1) == 1
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assert rootof((x - 1)*(x**3 + x + 3), 2) == rootof(x**3 + x + 3, 1)
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assert rootof((x - 1)*(x**3 + x + 3), 3) == rootof(x**3 + x + 3, 2)
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assert rootof((x - 1)*(x**3 + x + 3), -1) == rootof(x**3 + x + 3, 2)
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assert rootof((x - 1)*(x**3 + x + 3), -2) == rootof(x**3 + x + 3, 1)
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assert rootof((x - 1)*(x**3 + x + 3), -3) == 1
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assert rootof((x - 1)*(x**3 + x + 3), -4) == rootof(x**3 + x + 3, 0)
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assert rootof(x**4 + 3*x**3, 0) == -3
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assert rootof(x**4 + 3*x**3, 1) == 0
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assert rootof(x**4 + 3*x**3, 2) == 0
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assert rootof(x**4 + 3*x**3, 3) == 0
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raises(GeneratorsNeeded, lambda: rootof(0, 0))
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raises(GeneratorsNeeded, lambda: rootof(1, 0))
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raises(PolynomialError, lambda: rootof(Poly(0, x), 0))
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raises(PolynomialError, lambda: rootof(Poly(1, x), 0))
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raises(PolynomialError, lambda: rootof(x - y, 0))
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# issue 8617
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raises(PolynomialError, lambda: rootof(exp(x), 0))
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raises(NotImplementedError, lambda: rootof(x**3 - x + sqrt(2), 0))
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raises(NotImplementedError, lambda: rootof(x**3 - x + I, 0))
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raises(IndexError, lambda: rootof(x**2 - 1, -4))
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raises(IndexError, lambda: rootof(x**2 - 1, -3))
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raises(IndexError, lambda: rootof(x**2 - 1, 2))
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raises(IndexError, lambda: rootof(x**2 - 1, 3))
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raises(ValueError, lambda: rootof(x**2 - 1, x))
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assert rootof(Poly(x - y, x), 0) == y
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assert rootof(Poly(x**2 - y, x), 0) == -sqrt(y)
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assert rootof(Poly(x**2 - y, x), 1) == sqrt(y)
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assert rootof(Poly(x**3 - y, x), 0) == y**Rational(1, 3)
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assert rootof(y*x**3 + y*x + 2*y, x, 0) == -1
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raises(NotImplementedError, lambda: rootof(x**3 + x + 2*y, x, 0))
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assert rootof(x**3 + x + 1, 0).is_commutative is True
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def test_CRootOf_attributes():
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r = rootof(x**3 + x + 3, 0)
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assert r.is_number
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assert r.free_symbols == set()
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# if the following assertion fails then multivariate polynomials
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# are apparently supported and the RootOf.free_symbols routine
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# should be changed to return whatever symbols would not be
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# the PurePoly dummy symbol
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raises(NotImplementedError, lambda: rootof(Poly(x**3 + y*x + 1, x), 0))
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def test_CRootOf___eq__():
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assert (rootof(x**3 + x + 3, 0) == rootof(x**3 + x + 3, 0)) is True
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assert (rootof(x**3 + x + 3, 0) == rootof(x**3 + x + 3, 1)) is False
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assert (rootof(x**3 + x + 3, 1) == rootof(x**3 + x + 3, 1)) is True
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assert (rootof(x**3 + x + 3, 1) == rootof(x**3 + x + 3, 2)) is False
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assert (rootof(x**3 + x + 3, 2) == rootof(x**3 + x + 3, 2)) is True
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assert (rootof(x**3 + x + 3, 0) == rootof(y**3 + y + 3, 0)) is True
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assert (rootof(x**3 + x + 3, 0) == rootof(y**3 + y + 3, 1)) is False
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assert (rootof(x**3 + x + 3, 1) == rootof(y**3 + y + 3, 1)) is True
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assert (rootof(x**3 + x + 3, 1) == rootof(y**3 + y + 3, 2)) is False
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assert (rootof(x**3 + x + 3, 2) == rootof(y**3 + y + 3, 2)) is True
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def test_CRootOf___eval_Eq__():
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f = Function('f')
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eq = x**3 + x + 3
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r = rootof(eq, 2)
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r1 = rootof(eq, 1)
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assert Eq(r, r1) is S.false
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assert Eq(r, r) is S.true
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assert unchanged(Eq, r, x)
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assert Eq(r, 0) is S.false
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assert Eq(r, S.Infinity) is S.false
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assert Eq(r, I) is S.false
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assert unchanged(Eq, r, f(0))
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sol = solve(eq)
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for s in sol:
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if s.is_real:
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assert Eq(r, s) is S.false
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r = rootof(eq, 0)
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for s in sol:
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if s.is_real:
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assert Eq(r, s) is S.true
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eq = x**3 + x + 1
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sol = solve(eq)
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assert [Eq(rootof(eq, i), j) for i in range(3) for j in sol
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].count(True) == 3
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assert Eq(rootof(eq, 0), 1 + S.ImaginaryUnit) == False
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def test_CRootOf_is_real():
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assert rootof(x**3 + x + 3, 0).is_real is True
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assert rootof(x**3 + x + 3, 1).is_real is False
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assert rootof(x**3 + x + 3, 2).is_real is False
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def test_CRootOf_is_complex():
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assert rootof(x**3 + x + 3, 0).is_complex is True
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def test_CRootOf_subs():
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assert rootof(x**3 + x + 1, 0).subs(x, y) == rootof(y**3 + y + 1, 0)
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def test_CRootOf_diff():
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assert rootof(x**3 + x + 1, 0).diff(x) == 0
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assert rootof(x**3 + x + 1, 0).diff(y) == 0
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@slow
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def test_CRootOf_evalf():
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real = rootof(x**3 + x + 3, 0).evalf(n=20)
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assert real.epsilon_eq(Float("-1.2134116627622296341"))
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re, im = rootof(x**3 + x + 3, 1).evalf(n=20).as_real_imag()
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assert re.epsilon_eq( Float("0.60670583138111481707"))
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assert im.epsilon_eq(-Float("1.45061224918844152650"))
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re, im = rootof(x**3 + x + 3, 2).evalf(n=20).as_real_imag()
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assert re.epsilon_eq(Float("0.60670583138111481707"))
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assert im.epsilon_eq(Float("1.45061224918844152650"))
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p = legendre_poly(4, x, polys=True)
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roots = [str(r.n(17)) for r in p.real_roots()]
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# magnitudes are given by
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# sqrt(3/S(7) - 2*sqrt(6/S(5))/7)
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# and
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# sqrt(3/S(7) + 2*sqrt(6/S(5))/7)
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assert roots == [
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"-0.86113631159405258",
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"-0.33998104358485626",
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"0.33998104358485626",
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"0.86113631159405258",
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]
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re = rootof(x**5 - 5*x + 12, 0).evalf(n=20)
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assert re.epsilon_eq(Float("-1.84208596619025438271"))
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re, im = rootof(x**5 - 5*x + 12, 1).evalf(n=20).as_real_imag()
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assert re.epsilon_eq(Float("-0.351854240827371999559"))
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assert im.epsilon_eq(Float("-1.709561043370328882010"))
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re, im = rootof(x**5 - 5*x + 12, 2).evalf(n=20).as_real_imag()
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assert re.epsilon_eq(Float("-0.351854240827371999559"))
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assert im.epsilon_eq(Float("+1.709561043370328882010"))
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re, im = rootof(x**5 - 5*x + 12, 3).evalf(n=20).as_real_imag()
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assert re.epsilon_eq(Float("+1.272897223922499190910"))
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assert im.epsilon_eq(Float("-0.719798681483861386681"))
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re, im = rootof(x**5 - 5*x + 12, 4).evalf(n=20).as_real_imag()
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assert re.epsilon_eq(Float("+1.272897223922499190910"))
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assert im.epsilon_eq(Float("+0.719798681483861386681"))
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# issue 6393
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assert str(rootof(x**5 + 2*x**4 + x**3 - 68719476736, 0).n(3)) == '147.'
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eq = (531441*x**11 + 3857868*x**10 + 13730229*x**9 + 32597882*x**8 +
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55077472*x**7 + 60452000*x**6 + 32172064*x**5 - 4383808*x**4 -
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11942912*x**3 - 1506304*x**2 + 1453312*x + 512)
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a, b = rootof(eq, 1).n(2).as_real_imag()
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c, d = rootof(eq, 2).n(2).as_real_imag()
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assert a == c
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assert b < d
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assert b == -d
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# issue 6451
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r = rootof(legendre_poly(64, x), 7)
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assert r.n(2) == r.n(100).n(2)
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# issue 9019
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r0 = rootof(x**2 + 1, 0, radicals=False)
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r1 = rootof(x**2 + 1, 1, radicals=False)
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assert r0.n(4) == Float(-1.0, 4) * I
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assert r1.n(4) == Float(1.0, 4) * I
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# make sure verification is used in case a max/min traps the "root"
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assert str(rootof(4*x**5 + 16*x**3 + 12*x**2 + 7, 0).n(3)) == '-0.976'
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# watch out for UnboundLocalError
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c = CRootOf(90720*x**6 - 4032*x**4 + 84*x**2 - 1, 0)
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assert c._eval_evalf(2) # doesn't fail
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# watch out for imaginary parts that don't want to evaluate
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assert str(RootOf(x**16 + 32*x**14 + 508*x**12 + 5440*x**10 +
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39510*x**8 + 204320*x**6 + 755548*x**4 + 1434496*x**2 +
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877969, 10).n(2)) == '-3.4*I'
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assert abs(RootOf(x**4 + 10*x**2 + 1, 0).n(2)) < 0.4
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# check reset and args
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r = [RootOf(x**3 + x + 3, i) for i in range(3)]
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r[0]._reset()
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for ri in r:
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i = ri._get_interval()
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ri.n(2)
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assert i != ri._get_interval()
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ri._reset()
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assert i == ri._get_interval()
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assert i == i.func(*i.args)
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def test_CRootOf_evalf_caching_bug():
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r = rootof(x**5 - 5*x + 12, 1)
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r.n()
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a = r._get_interval()
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r = rootof(x**5 - 5*x + 12, 1)
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r.n()
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b = r._get_interval()
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assert a == b
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def test_CRootOf_real_roots():
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assert Poly(x**5 + x + 1).real_roots() == [rootof(x**3 - x**2 + 1, 0)]
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assert Poly(x**5 + x + 1).real_roots(radicals=False) == [rootof(
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x**3 - x**2 + 1, 0)]
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# https://github.com/sympy/sympy/issues/20902
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p = Poly(-3*x**4 - 10*x**3 - 12*x**2 - 6*x - 1, x, domain='ZZ')
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assert CRootOf.real_roots(p) == [S(-1), S(-1), S(-1), S(-1)/3]
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def test_CRootOf_all_roots():
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assert Poly(x**5 + x + 1).all_roots() == [
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rootof(x**3 - x**2 + 1, 0),
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Rational(-1, 2) - sqrt(3)*I/2,
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Rational(-1, 2) + sqrt(3)*I/2,
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rootof(x**3 - x**2 + 1, 1),
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rootof(x**3 - x**2 + 1, 2),
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]
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assert Poly(x**5 + x + 1).all_roots(radicals=False) == [
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rootof(x**3 - x**2 + 1, 0),
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rootof(x**2 + x + 1, 0, radicals=False),
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rootof(x**2 + x + 1, 1, radicals=False),
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rootof(x**3 - x**2 + 1, 1),
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rootof(x**3 - x**2 + 1, 2),
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]
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def test_CRootOf_eval_rational():
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p = legendre_poly(4, x, polys=True)
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roots = [r.eval_rational(n=18) for r in p.real_roots()]
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for root in roots:
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assert isinstance(root, Rational)
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roots = [str(root.n(17)) for root in roots]
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assert roots == [
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"-0.86113631159405258",
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"-0.33998104358485626",
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"0.33998104358485626",
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"0.86113631159405258",
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]
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def test_CRootOf_lazy():
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# irreducible poly with both real and complex roots:
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f = Poly(x**3 + 2*x + 2)
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# real root:
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CRootOf.clear_cache()
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r = CRootOf(f, 0)
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# Not yet in cache, after construction:
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assert r.poly not in rootoftools._reals_cache
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assert r.poly not in rootoftools._complexes_cache
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r.evalf()
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# In cache after evaluation:
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assert r.poly in rootoftools._reals_cache
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assert r.poly not in rootoftools._complexes_cache
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# complex root:
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CRootOf.clear_cache()
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r = CRootOf(f, 1)
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# Not yet in cache, after construction:
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assert r.poly not in rootoftools._reals_cache
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assert r.poly not in rootoftools._complexes_cache
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r.evalf()
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# In cache after evaluation:
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assert r.poly in rootoftools._reals_cache
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assert r.poly in rootoftools._complexes_cache
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# composite poly with both real and complex roots:
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f = Poly((x**2 - 2)*(x**2 + 1))
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# real root:
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CRootOf.clear_cache()
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r = CRootOf(f, 0)
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# In cache immediately after construction:
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assert r.poly in rootoftools._reals_cache
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assert r.poly not in rootoftools._complexes_cache
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# complex root:
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CRootOf.clear_cache()
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r = CRootOf(f, 2)
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# In cache immediately after construction:
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assert r.poly in rootoftools._reals_cache
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assert r.poly in rootoftools._complexes_cache
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def test_RootSum___new__():
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f = x**3 + x + 3
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g = Lambda(r, log(r*x))
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s = RootSum(f, g)
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assert isinstance(s, RootSum) is True
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assert RootSum(f**2, g) == 2*RootSum(f, g)
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assert RootSum((x - 7)*f**3, g) == log(7*x) + 3*RootSum(f, g)
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# issue 5571
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assert hash(RootSum((x - 7)*f**3, g)) == hash(log(7*x) + 3*RootSum(f, g))
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raises(MultivariatePolynomialError, lambda: RootSum(x**3 + x + y))
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raises(ValueError, lambda: RootSum(x**2 + 3, lambda x: x))
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assert RootSum(f, exp) == RootSum(f, Lambda(x, exp(x)))
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assert RootSum(f, log) == RootSum(f, Lambda(x, log(x)))
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assert isinstance(RootSum(f, auto=False), RootSum) is True
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assert RootSum(f) == 0
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assert RootSum(f, Lambda(x, x)) == 0
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assert RootSum(f, Lambda(x, x**2)) == -2
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assert RootSum(f, Lambda(x, 1)) == 3
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assert RootSum(f, Lambda(x, 2)) == 6
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assert RootSum(f, auto=False).is_commutative is True
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assert RootSum(f, Lambda(x, 1/(x + x**2))) == Rational(11, 3)
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assert RootSum(f, Lambda(x, y/(x + x**2))) == Rational(11, 3)*y
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assert RootSum(x**2 - 1, Lambda(x, 3*x**2), x) == 6
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assert RootSum(x**2 - y, Lambda(x, 3*x**2), x) == 6*y
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assert RootSum(x**2 - 1, Lambda(x, z*x**2), x) == 2*z
|
|
assert RootSum(x**2 - y, Lambda(x, z*x**2), x) == 2*z*y
|
|
|
|
assert RootSum(
|
|
x**2 - 1, Lambda(x, exp(x)), quadratic=True) == exp(-1) + exp(1)
|
|
|
|
assert RootSum(x**3 + a*x + a**3, tan, x) == \
|
|
RootSum(x**3 + x + 1, Lambda(x, tan(a*x)))
|
|
assert RootSum(a**3*x**3 + a*x + 1, tan, x) == \
|
|
RootSum(x**3 + x + 1, Lambda(x, tan(x/a)))
|
|
|
|
|
|
def test_RootSum_free_symbols():
|
|
assert RootSum(x**3 + x + 3, Lambda(r, exp(r))).free_symbols == set()
|
|
assert RootSum(x**3 + x + 3, Lambda(r, exp(a*r))).free_symbols == {a}
|
|
assert RootSum(
|
|
x**3 + x + y, Lambda(r, exp(a*r)), x).free_symbols == {a, y}
|
|
|
|
|
|
def test_RootSum___eq__():
|
|
f = Lambda(x, exp(x))
|
|
|
|
assert (RootSum(x**3 + x + 1, f) == RootSum(x**3 + x + 1, f)) is True
|
|
assert (RootSum(x**3 + x + 1, f) == RootSum(y**3 + y + 1, f)) is True
|
|
|
|
assert (RootSum(x**3 + x + 1, f) == RootSum(x**3 + x + 2, f)) is False
|
|
assert (RootSum(x**3 + x + 1, f) == RootSum(y**3 + y + 2, f)) is False
|
|
|
|
|
|
def test_RootSum_doit():
|
|
rs = RootSum(x**2 + 1, exp)
|
|
|
|
assert isinstance(rs, RootSum) is True
|
|
assert rs.doit() == exp(-I) + exp(I)
|
|
|
|
rs = RootSum(x**2 + a, exp, x)
|
|
|
|
assert isinstance(rs, RootSum) is True
|
|
assert rs.doit() == exp(-sqrt(-a)) + exp(sqrt(-a))
|
|
|
|
|
|
def test_RootSum_evalf():
|
|
rs = RootSum(x**2 + 1, exp)
|
|
|
|
assert rs.evalf(n=20, chop=True).epsilon_eq(Float("1.0806046117362794348"))
|
|
assert rs.evalf(n=15, chop=True).epsilon_eq(Float("1.08060461173628"))
|
|
|
|
rs = RootSum(x**2 + a, exp, x)
|
|
|
|
assert rs.evalf() == rs
|
|
|
|
|
|
def test_RootSum_diff():
|
|
f = x**3 + x + 3
|
|
|
|
g = Lambda(r, exp(r*x))
|
|
h = Lambda(r, r*exp(r*x))
|
|
|
|
assert RootSum(f, g).diff(x) == RootSum(f, h)
|
|
|
|
|
|
def test_RootSum_subs():
|
|
f = x**3 + x + 3
|
|
g = Lambda(r, exp(r*x))
|
|
|
|
F = y**3 + y + 3
|
|
G = Lambda(r, exp(r*y))
|
|
|
|
assert RootSum(f, g).subs(y, 1) == RootSum(f, g)
|
|
assert RootSum(f, g).subs(x, y) == RootSum(F, G)
|
|
|
|
|
|
def test_RootSum_rational():
|
|
assert RootSum(
|
|
z**5 - z + 1, Lambda(z, z/(x - z))) == (4*x - 5)/(x**5 - x + 1)
|
|
|
|
f = 161*z**3 + 115*z**2 + 19*z + 1
|
|
g = Lambda(z, z*log(
|
|
-3381*z**4/4 - 3381*z**3/4 - 625*z**2/2 - z*Rational(125, 2) - 5 + exp(x)))
|
|
|
|
assert RootSum(f, g).diff(x) == -(
|
|
(5*exp(2*x) - 6*exp(x) + 4)*exp(x)/(exp(3*x) - exp(2*x) + 1))/7
|
|
|
|
|
|
def test_RootSum_independent():
|
|
f = (x**3 - a)**2*(x**4 - b)**3
|
|
|
|
g = Lambda(x, 5*tan(x) + 7)
|
|
h = Lambda(x, tan(x))
|
|
|
|
r0 = RootSum(x**3 - a, h, x)
|
|
r1 = RootSum(x**4 - b, h, x)
|
|
|
|
assert RootSum(f, g, x).as_ordered_terms() == [10*r0, 15*r1, 126]
|
|
|
|
|
|
def test_issue_7876():
|
|
l1 = Poly(x**6 - x + 1, x).all_roots()
|
|
l2 = [rootof(x**6 - x + 1, i) for i in range(6)]
|
|
assert frozenset(l1) == frozenset(l2)
|
|
|
|
|
|
def test_issue_8316():
|
|
f = Poly(7*x**8 - 9)
|
|
assert len(f.all_roots()) == 8
|
|
f = Poly(7*x**8 - 10)
|
|
assert len(f.all_roots()) == 8
|
|
|
|
|
|
def test__imag_count():
|
|
from sympy.polys.rootoftools import _imag_count_of_factor
|
|
def imag_count(p):
|
|
return sum([_imag_count_of_factor(f)*m for f, m in
|
|
p.factor_list()[1]])
|
|
assert imag_count(Poly(x**6 + 10*x**2 + 1)) == 2
|
|
assert imag_count(Poly(x**2)) == 0
|
|
assert imag_count(Poly([1]*3 + [-1], x)) == 0
|
|
assert imag_count(Poly(x**3 + 1)) == 0
|
|
assert imag_count(Poly(x**2 + 1)) == 2
|
|
assert imag_count(Poly(x**2 - 1)) == 0
|
|
assert imag_count(Poly(x**4 - 1)) == 2
|
|
assert imag_count(Poly(x**4 + 1)) == 0
|
|
assert imag_count(Poly([1, 2, 3], x)) == 0
|
|
assert imag_count(Poly(x**3 + x + 1)) == 0
|
|
assert imag_count(Poly(x**4 + x + 1)) == 0
|
|
def q(r1, r2, p):
|
|
return Poly(((x - r1)*(x - r2)).subs(x, x**p), x)
|
|
assert imag_count(q(-1, -2, 2)) == 4
|
|
assert imag_count(q(-1, 2, 2)) == 2
|
|
assert imag_count(q(1, 2, 2)) == 0
|
|
assert imag_count(q(1, 2, 4)) == 4
|
|
assert imag_count(q(-1, 2, 4)) == 2
|
|
assert imag_count(q(-1, -2, 4)) == 0
|
|
|
|
|
|
def test_RootOf_is_imaginary():
|
|
r = RootOf(x**4 + 4*x**2 + 1, 1)
|
|
i = r._get_interval()
|
|
assert r.is_imaginary and i.ax*i.bx <= 0
|
|
|
|
|
|
def test_is_disjoint():
|
|
eq = x**3 + 5*x + 1
|
|
ir = rootof(eq, 0)._get_interval()
|
|
ii = rootof(eq, 1)._get_interval()
|
|
assert ir.is_disjoint(ii)
|
|
assert ii.is_disjoint(ir)
|
|
|
|
|
|
def test_pure_key_dict():
|
|
p = D()
|
|
assert (x in p) is False
|
|
assert (1 in p) is False
|
|
p[x] = 1
|
|
assert x in p
|
|
assert y in p
|
|
assert p[y] == 1
|
|
raises(KeyError, lambda: p[1])
|
|
def dont(k):
|
|
p[k] = 2
|
|
raises(ValueError, lambda: dont(1))
|
|
|
|
|
|
@slow
|
|
def test_eval_approx_relative():
|
|
CRootOf.clear_cache()
|
|
t = [CRootOf(x**3 + 10*x + 1, i) for i in range(3)]
|
|
assert [i.eval_rational(1e-1) for i in t] == [
|
|
Rational(-21, 220), Rational(15, 256) - I*805/256,
|
|
Rational(15, 256) + I*805/256]
|
|
t[0]._reset()
|
|
assert [i.eval_rational(1e-1, 1e-4) for i in t] == [
|
|
Rational(-21, 220), Rational(3275, 65536) - I*414645/131072,
|
|
Rational(3275, 65536) + I*414645/131072]
|
|
assert S(t[0]._get_interval().dx) < 1e-1
|
|
assert S(t[1]._get_interval().dx) < 1e-1
|
|
assert S(t[1]._get_interval().dy) < 1e-4
|
|
assert S(t[2]._get_interval().dx) < 1e-1
|
|
assert S(t[2]._get_interval().dy) < 1e-4
|
|
t[0]._reset()
|
|
assert [i.eval_rational(1e-4, 1e-4) for i in t] == [
|
|
Rational(-2001, 20020), Rational(6545, 131072) - I*414645/131072,
|
|
Rational(6545, 131072) + I*414645/131072]
|
|
assert S(t[0]._get_interval().dx) < 1e-4
|
|
assert S(t[1]._get_interval().dx) < 1e-4
|
|
assert S(t[1]._get_interval().dy) < 1e-4
|
|
assert S(t[2]._get_interval().dx) < 1e-4
|
|
assert S(t[2]._get_interval().dy) < 1e-4
|
|
# in the following, the actual relative precision is
|
|
# less than tested, but it should never be greater
|
|
t[0]._reset()
|
|
assert [i.eval_rational(n=2) for i in t] == [
|
|
Rational(-202201, 2024022), Rational(104755, 2097152) - I*6634255/2097152,
|
|
Rational(104755, 2097152) + I*6634255/2097152]
|
|
assert abs(S(t[0]._get_interval().dx)/t[0]) < 1e-2
|
|
assert abs(S(t[1]._get_interval().dx)/t[1]).n() < 1e-2
|
|
assert abs(S(t[1]._get_interval().dy)/t[1]).n() < 1e-2
|
|
assert abs(S(t[2]._get_interval().dx)/t[2]).n() < 1e-2
|
|
assert abs(S(t[2]._get_interval().dy)/t[2]).n() < 1e-2
|
|
t[0]._reset()
|
|
assert [i.eval_rational(n=3) for i in t] == [
|
|
Rational(-202201, 2024022), Rational(1676045, 33554432) - I*106148135/33554432,
|
|
Rational(1676045, 33554432) + I*106148135/33554432]
|
|
assert abs(S(t[0]._get_interval().dx)/t[0]) < 1e-3
|
|
assert abs(S(t[1]._get_interval().dx)/t[1]).n() < 1e-3
|
|
assert abs(S(t[1]._get_interval().dy)/t[1]).n() < 1e-3
|
|
assert abs(S(t[2]._get_interval().dx)/t[2]).n() < 1e-3
|
|
assert abs(S(t[2]._get_interval().dy)/t[2]).n() < 1e-3
|
|
|
|
t[0]._reset()
|
|
a = [i.eval_approx(2) for i in t]
|
|
assert [str(i) for i in a] == [
|
|
'-0.10', '0.05 - 3.2*I', '0.05 + 3.2*I']
|
|
assert all(abs(((a[i] - t[i])/t[i]).n()) < 1e-2 for i in range(len(a)))
|
|
|
|
|
|
def test_issue_15920():
|
|
r = rootof(x**5 - x + 1, 0)
|
|
p = Integral(x, (x, 1, y))
|
|
assert unchanged(Eq, r, p)
|
|
|
|
|
|
def test_issue_19113():
|
|
eq = y**3 - y + 1
|
|
# generator is a canonical x in RootOf
|
|
assert str(Poly(eq).real_roots()) == '[CRootOf(x**3 - x + 1, 0)]'
|
|
assert str(Poly(eq.subs(y, tan(y))).real_roots()
|
|
) == '[CRootOf(x**3 - x + 1, 0)]'
|
|
assert str(Poly(eq.subs(y, tan(x))).real_roots()
|
|
) == '[CRootOf(x**3 - x + 1, 0)]'
|