def test_CRootOf___eval_Eq__():
f = Function('f')
eq = x**3 + x + 3
r = rootof(eq, 2)
r1 = rootof(eq, 1)
assert Eq(r, r1) is S.false
assert Eq(r, r) is S.true
assert Eq(r, x) is S.false
assert Eq(r, 0) is S.false
assert Eq(r, S.Infinity) is S.false
assert Eq(r, I) is S.false
assert Eq(r, f(0)) is S.false
assert Eq(r, f(0)) is S.false
sol = solve(eq)
for s in sol:
if s.is_real:
assert Eq(r, s) is S.false
r = rootof(eq, 0)
for s in sol:
if s.is_real:
assert Eq(r, s) is S.true
eq = x**3 + x + 1
sol = solve(eq)
assert [Eq(rootof(eq, i), j) for i in range(3) for j in sol] == [
False, False, True, False, True, False, True, False, False]
assert Eq(rootof(eq, 0), 1 + S.ImaginaryUnit) == False
def test_CRootOf_evalf_caching_bug():
r = rootof(x**5 - 5*x + 12, 1)
r.n()
a = r._get_interval()
r = rootof(x**5 - 5*x + 12, 1)
r.n()
b = r._get_interval()
assert a == b
def test_CRootOf_attributes():
r = rootof(x**3 + x + 3, 0)
assert r.is_number
assert r.free_symbols == set()
# if the following assertion fails then multivariate polynomials
# are apparently supported and the RootOf.free_symbols routine
# should be changed to return whatever symbols would not be
# the PurePoly dummy symbol
raises(NotImplementedError, lambda: rootof(Poly(x**3 + y*x + 1, x), 0))
def test_solve_univariate_inequality():
assert isolve(x**2 >= 4, x, relational=False) == Union(Interval(-oo, -2),
Interval(2, oo))
assert isolve(x**2 >= 4, x) == Or(And(Le(2, x), Lt(x, oo)), And(Le(x, -2),
Lt(-oo, x)))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x, relational=False) == \
Union(Interval(1, 2), Interval(3, oo))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x) == \
Or(And(Le(1, x), Le(x, 2)), And(Le(3, x), Lt(x, oo)))
assert isolve((x - 1)*(x - 2)*(x - 4) < 0, x, domain = FiniteSet(0, 3)) == \
Or(Eq(x, 0), Eq(x, 3))
# issue 2785:
assert isolve(x**3 - 2*x - 1 > 0, x, relational=False) == \
Union(Interval(-1, -sqrt(5)/2 + S(1)/2, True, True),
Interval(S(1)/2 + sqrt(5)/2, oo, True, True))
# issue 2794:
assert isolve(x**3 - x**2 + x - 1 > 0, x, relational=False) == \
Interval(1, oo, True)
#issue 13105
assert isolve((x + I)*(x + 2*I) < 0, x) == Eq(x, 0)
assert isolve(((x - 1)*(x - 2) + I)*((x - 1)*(x - 2) + 2*I) < 0, x) == Or(Eq(x, 1), Eq(x, 2))
assert isolve((((x - 1)*(x - 2) + I)*((x - 1)*(x - 2) + 2*I))/(x - 2) > 0, x) == Eq(x, 1)
raises (ValueError, lambda: isolve((x**2 - 3*x*I + 2)/x < 0, x))
# numerical testing in valid() is needed
assert isolve(x**7 - x - 2 > 0, x) == \
And(rootof(x**7 - x - 2, 0) < x, x < oo)
# handle numerator and denominator; although these would be handled as
# rational inequalities, these test confirm that the right thing is done
# when the domain is EX (e.g. when 2 is replaced with sqrt(2))
assert isolve(1/(x - 2) > 0, x) == And(S(2) < x, x < oo)
den = ((x - 1)*(x - 2)).expand()
assert isolve((x - 1)/den <= 0, x) == \
Or(And(-oo < x, x < 1), And(S(1) < x, x < 2))
n = Dummy('n')
raises(NotImplementedError, lambda: isolve(Abs(x) <= n, x, relational=False))
c1 = Dummy("c1", positive=True)
raises(NotImplementedError, lambda: isolve(n/c1 < 0, c1))
n = Dummy('n', negative=True)
assert isolve(n/c1 > -2, c1) == (-n/2 < c1)
assert isolve(n/c1 < 0, c1) == True
assert isolve(n/c1 > 0, c1) == False
zero = cos(1)**2 + sin(1)**2 - 1
raises(NotImplementedError, lambda: isolve(x**2 < zero, x))
raises(NotImplementedError, lambda: isolve(
x**2 < zero*I, x))
raises(NotImplementedError, lambda: isolve(1/(x - y) < 2, x))
raises(NotImplementedError, lambda: isolve(1/(x - y) < 0, x))
raises(TypeError, lambda: isolve(x - I < 0, x))
zero = x**2 + x - x*(x + 1)
assert isolve(zero < 0, x, relational=False) is S.EmptySet
assert isolve(zero <= 0, x, relational=False) is S.Reals
# make sure iter_solutions gets a default value
raises(NotImplementedError, lambda: isolve(
Eq(cos(x)**2 + sin(x)**2, 1), x))
def test_solve_univariate_inequality():
assert isolve(x**2 >= 4, x, relational=False) == Union(Interval(-oo, -2),
Interval(2, oo))
assert isolve(x**2 >= 4, x) == Or(And(Le(2, x), Lt(x, oo)), And(Le(x, -2),
Lt(-oo, x)))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x, relational=False) == \
Union(Interval(1, 2), Interval(3, oo))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x) == \
Or(And(Le(1, x), Le(x, 2)), And(Le(3, x), Lt(x, oo)))
# issue 2785:
assert isolve(x**3 - 2*x - 1 > 0, x, relational=False) == \
Union(Interval(-1, -sqrt(5)/2 + S(1)/2, True, True),
Interval(S(1)/2 + sqrt(5)/2, oo, True, True))
# issue 2794:
assert isolve(x**3 - x**2 + x - 1 > 0, x, relational=False) == \
Interval(1, oo, True)
# XXX should be limited in domain, e.g. between 0 and 2*pi
assert isolve(sin(x) < S.Half, x) == \
Or(And(-oo < x, x < pi/6), And(5*pi/6 < x, x < oo))
assert isolve(sin(x) > S.Half, x) == And(pi/6 < x, x < 5*pi/6)
# numerical testing in valid() is needed
assert isolve(x**7 - x - 2 > 0, x) == \
And(rootof(x**7 - x - 2, 0) < x, x < oo)
# handle numerator and denominator; although these would be handled as
# rational inequalities, these test confirm that the right thing is done
# when the domain is EX (e.g. when 2 is replaced with sqrt(2))
assert isolve(1/(x - 2) > 0, x) == And(S(2) < x, x < oo)
den = ((x - 1)*(x - 2)).expand()
assert isolve((x - 1)/den <= 0, x) == \
Or(And(-oo < x, x < 1), And(S(1) < x, x < 2))
def test_nfloat():
from sympy.core.basic import _aresame
from sympy.polys.rootoftools import rootof
x = Symbol("x")
eq = x**(S(4)/3) + 4*x**(S(1)/3)/3
assert _aresame(nfloat(eq), x**(S(4)/3) + (4.0/3)*x**(S(1)/3))
assert _aresame(nfloat(eq, exponent=True), x**(4.0/3) + (4.0/3)*x**(1.0/3))
eq = x**(S(4)/3) + 4*x**(x/3)/3
assert _aresame(nfloat(eq), x**(S(4)/3) + (4.0/3)*x**(x/3))
big = 12345678901234567890
# specify precision to match value used in nfloat
Float_big = Float(big, 15)
assert _aresame(nfloat(big), Float_big)
assert _aresame(nfloat(big*x), Float_big*x)
assert _aresame(nfloat(x**big, exponent=True), x**Float_big)
assert nfloat({x: sqrt(2)}) == {x: nfloat(sqrt(2))}
assert nfloat({sqrt(2): x}) == {sqrt(2): x}
assert nfloat(cos(x + sqrt(2))) == cos(x + nfloat(sqrt(2)))
# issue 6342
f = S('x*lamda + lamda**3*(x/2 + 1/2) + lamda**2 + 1/4')
assert not any(a.free_symbols for a in solveset(f.subs(x, -0.139)))
# issue 6632
assert nfloat(-100000*sqrt(2500000001) + 5000000001) == \
9.99999999800000e-11
# issue 7122
eq = cos(3*x**4 + y)*rootof(x**5 + 3*x**3 + 1, 0)
assert str(nfloat(eq, exponent=False, n=1)) == '-0.7*cos(3.0*x**4 + y)'
def test_solve_univariate_inequality():
assert isolve(x**2 >= 4, x, relational=False) == Union(Interval(-oo, -2),
Interval(2, oo))
assert isolve(x**2 >= 4, x) == Or(And(Le(2, x), Lt(x, oo)), And(Le(x, -2),
Lt(-oo, x)))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x, relational=False) == \
Union(Interval(1, 2), Interval(3, oo))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x) == \
Or(And(Le(1, x), Le(x, 2)), And(Le(3, x), Lt(x, oo)))
# issue 2785:
assert isolve(x**3 - 2*x - 1 > 0, x, relational=False) == \
Union(Interval(-1, -sqrt(5)/2 + S(1)/2, True, True),
Interval(S(1)/2 + sqrt(5)/2, oo, True, True))
# issue 2794:
assert isolve(x**3 - x**2 + x - 1 > 0, x, relational=False) == \
Interval(1, oo, True)
# numerical testing in valid() is needed
assert isolve(x**7 - x - 2 > 0, x) == \
And(rootof(x**7 - x - 2, 0) < x, x < oo)
# handle numerator and denominator; although these would be handled as
# rational inequalities, these test confirm that the right thing is done
# when the domain is EX (e.g. when 2 is replaced with sqrt(2))
assert isolve(1/(x - 2) > 0, x) == And(S(2) < x, x < oo)
den = ((x - 1)*(x - 2)).expand()
assert isolve((x - 1)/den <= 0, x) == \
Or(And(-oo < x, x < 1), And(S(1) < x, x < 2))
n = Dummy('n')
raises(NotImplementedError, lambda: isolve(Abs(x) <= n, x, relational=False))
def test_issue_8235():
assert reduce_inequalities(x**2 - 1 < 0) == \
And(S.NegativeOne < x, x < 1)
assert reduce_inequalities(x**2 - 1 <= 0) == \
And(S.NegativeOne <= x, x <= 1)
assert reduce_inequalities(x**2 - 1 > 0) == \
Or(And(-oo < x, x < -1), And(x < oo, S.One < x))
assert reduce_inequalities(x**2 - 1 >= 0) == \
Or(And(-oo < x, x <= -1), And(S.One <= x, x < oo))
eq = x**8 + x - 9 # we want CRootOf solns here
sol = solve(eq >= 0)
tru = Or(And(rootof(eq, 1) <= x, x < oo), And(-oo < x, x <= rootof(eq, 0)))
assert sol == tru
# recast vanilla as real
assert solve(sqrt((-x + 1)**2) < 1) == And(S.Zero < x, x < 2)
def test_issue_8235():
assert reduce_inequalities(x**2 - 1 < 0) == \
And(S(-1) < x, x < S(1))
assert reduce_inequalities(x**2 - 1 <= 0) == \
And(S(-1) <= x, x <= 1)
assert reduce_inequalities(x**2 - 1 > 0) == \
Or(And(-oo < x, x < -1), And(x < oo, S(1) < x))
assert reduce_inequalities(x**2 - 1 >= 0) == \
Or(And(-oo < x, x <= S(-1)), And(S(1) <= x, x < oo))
eq = x**8 + x - 9 # we want CRootOf solns here
sol = solve(eq >= 0)
tru = Or(And(rootof(eq, 1) <= x, x < oo), And(-oo < x, x <= rootof(eq, 0)))
assert sol == tru
# recast vanilla as real
assert solve(sqrt((-x + 1)**2) < 1) == And(S(0) < x, x < 2)
def test_solve_univariate_inequality():
assert isolve(x**2 >= 4,
x, relational=False) == Union(Interval(-oo, -2),
Interval(2, oo))
assert isolve(x**2 >= 4, x) == Or(And(Le(2, x), Lt(x, oo)),
And(Le(x, -2), Lt(-oo, x)))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x, relational=False) == \
Union(Interval(1, 2), Interval(3, oo))
assert isolve((x - 1)*(x - 2)*(x - 3) >= 0, x) == \
Or(And(Le(1, x), Le(x, 2)), And(Le(3, x), Lt(x, oo)))
# issue 2785:
assert isolve(x**3 - 2*x - 1 > 0, x, relational=False) == \
Union(Interval(-1, -sqrt(5)/2 + S(1)/2, True, True),
Interval(S(1)/2 + sqrt(5)/2, oo, True, True))
# issue 2794:
assert isolve(x**3 - x**2 + x - 1 > 0, x, relational=False) == \
Interval(1, oo, True)
#issue 13105
assert isolve((x + I) * (x + 2 * I) < 0, x) == Eq(x, 0)
assert isolve(((x - 1) * (x - 2) + I) * ((x - 1) * (x - 2) + 2 * I) < 0,
x) == Or(Eq(x, 1), Eq(x, 2))
assert isolve(
(((x - 1) * (x - 2) + I) * ((x - 1) * (x - 2) + 2 * I)) / (x - 2) > 0,
x) == Eq(x, 1)
raises(ValueError, lambda: isolve((x**2 - 3 * x * I + 2) / x < 0, x))
# numerical testing in valid() is needed
assert isolve(x**7 - x - 2 > 0, x) == \
And(rootof(x**7 - x - 2, 0) < x, x < oo)
# handle numerator and denominator; although these would be handled as
# rational inequalities, these test confirm that the right thing is done
# when the domain is EX (e.g. when 2 is replaced with sqrt(2))
assert isolve(1 / (x - 2) > 0, x) == And(S(2) < x, x < oo)
den = ((x - 1) * (x - 2)).expand()
assert isolve((x - 1)/den <= 0, x) == \
Or(And(-oo < x, x < 1), And(S(1) < x, x < 2))
n = Dummy('n')
raises(NotImplementedError,
lambda: isolve(Abs(x) <= n, x, relational=False))
c1 = Dummy("c1", positive=True)
raises(NotImplementedError, lambda: isolve(n / c1 < 0, c1))
n = Dummy('n', negative=True)
assert isolve(n / c1 > -2, c1) == (-n / 2 < c1)
assert isolve(n / c1 < 0, c1) == True
assert isolve(n / c1 > 0, c1) == False
zero = cos(1)**2 + sin(1)**2 - 1
raises(NotImplementedError, lambda: isolve(x**2 < zero, x))
raises(NotImplementedError, lambda: isolve(x**2 < zero * I, x))
raises(NotImplementedError, lambda: isolve(1 / (x - y) < 2, x))
raises(NotImplementedError, lambda: isolve(1 / (x - y) < 0, x))
raises(TypeError, lambda: isolve(x - I < 0, x))
# make sure iter_solutions gets a default value
raises(NotImplementedError,
lambda: isolve(Eq(cos(x)**2 + sin(x)**2, 1), x))
def test_nfloat():
from sympy.core.basic import _aresame
from sympy.polys.rootoftools import rootof
x = Symbol("x")
eq = x**(S(4) / 3) + 4 * x**(S(1) / 3) / 3
assert _aresame(nfloat(eq), x**(S(4) / 3) + (4.0 / 3) * x**(S(1) / 3))
assert _aresame(nfloat(eq, exponent=True),
x**(4.0 / 3) + (4.0 / 3) * x**(1.0 / 3))
eq = x**(S(4) / 3) + 4 * x**(x / 3) / 3
assert _aresame(nfloat(eq), x**(S(4) / 3) + (4.0 / 3) * x**(x / 3))
big = 12345678901234567890
# specify precision to match value used in nfloat
Float_big = Float(big, 15)
assert _aresame(nfloat(big), Float_big)
assert _aresame(nfloat(big * x), Float_big * x)
assert _aresame(nfloat(x**big, exponent=True), x**Float_big)
assert nfloat(cos(x + sqrt(2))) == cos(x + nfloat(sqrt(2)))
# issue 6342
f = S('x*lamda + lamda**3*(x/2 + 1/2) + lamda**2 + 1/4')
assert not any(a.free_symbols for a in solveset(f.subs(x, -0.139)))
# issue 6632
assert nfloat(-100000*sqrt(2500000001) + 5000000001) == \
9.99999999800000e-11
# issue 7122
eq = cos(3 * x**4 + y) * rootof(x**5 + 3 * x**3 + 1, 0)
assert str(nfloat(eq, exponent=False, n=1)) == '-0.7*cos(3.0*x**4 + y)'
# issue 10933
for t in (dict, Dict):
d = t({S.Half: S.Half})
n = nfloat(d)
assert isinstance(n, t)
assert _aresame(list(n.items()).pop(), (S.Half, Float(.5)))
for t in (dict, Dict):
d = t({S.Half: S.Half})
n = nfloat(d, dkeys=True)
assert isinstance(n, t)
assert _aresame(list(n.items()).pop(), (Float(.5), Float(.5)))
d = [S.Half]
n = nfloat(d)
assert type(n) is list
assert _aresame(n[0], Float(.5))
assert _aresame(nfloat(Eq(x, S.Half)).rhs, Float(.5))
assert _aresame(nfloat(S(True)), S(True))
assert _aresame(nfloat(Tuple(S.Half))[0], Float(.5))
assert nfloat(Eq((3 - I)**2 / 2 + I, 0)) == S.false
# pass along kwargs
assert nfloat([{S.Half: x}], dkeys=True) == [{Float(0.5): x}]
def test_CRootOf_all_roots():
assert Poly(x**5 + x + 1).all_roots() == [
rootof(x**3 - x**2 + 1, 0),
-S(1)/2 - sqrt(3)*I/2,
-S(1)/2 + sqrt(3)*I/2,
rootof(x**3 - x**2 + 1, 1),
rootof(x**3 - x**2 + 1, 2),
]
assert Poly(x**5 + x + 1).all_roots(radicals=False) == [
rootof(x**3 - x**2 + 1, 0),
rootof(x**2 + x + 1, 0, radicals=False),
rootof(x**2 + x + 1, 1, radicals=False),
rootof(x**3 - x**2 + 1, 1),
rootof(x**3 - x**2 + 1, 2),
]
def test_CRootOf_all_roots():
assert Poly(x**5 + x + 1).all_roots() == [
rootof(x**3 - x**2 + 1, 0),
-S(1) / 2 - sqrt(3) * I / 2,
-S(1) / 2 + sqrt(3) * I / 2,
rootof(x**3 - x**2 + 1, 1),
rootof(x**3 - x**2 + 1, 2),
]
assert Poly(x**5 + x + 1).all_roots(radicals=False) == [
rootof(x**3 - x**2 + 1, 0),
rootof(x**2 + x + 1, 0, radicals=False),
rootof(x**2 + x + 1, 1, radicals=False),
rootof(x**3 - x**2 + 1, 1),
rootof(x**3 - x**2 + 1, 2),
]
def test_CRootOf_all_roots():
assert Poly(x**5 + x + 1).all_roots() == [
rootof(x**3 - x**2 + 1, 0),
Rational(-1, 2) - sqrt(3) * I / 2,
Rational(-1, 2) + sqrt(3) * I / 2,
rootof(x**3 - x**2 + 1, 1),
rootof(x**3 - x**2 + 1, 2),
]
assert Poly(x**5 + x + 1).all_roots(radicals=False) == [
rootof(x**3 - x**2 + 1, 0),
rootof(x**2 + x + 1, 0, radicals=False),
rootof(x**2 + x + 1, 1, radicals=False),
rootof(x**3 - x**2 + 1, 1),
rootof(x**3 - x**2 + 1, 2),
]
def test_CRootOf___eval_Eq__():
f = Function('f')
r = rootof(x**3 + x + 3, 2)
r1 = rootof(x**3 + x + 3, 1)
assert Eq(r, r1) is S.false
assert Eq(r, r) is S.true
assert Eq(r, x) is S.false
assert Eq(r, 0) is S.false
assert Eq(r, S.Infinity) is S.false
assert Eq(r, I) is S.false
assert Eq(r, f(0)) is S.false
assert Eq(r, f(0)) is S.false
sol = solve(r.expr)
for s in sol:
if s.is_real:
assert Eq(r, s) is S.false
r = rootof(r.expr, 0)
for s in sol:
if s.is_real:
assert Eq(r, s) is S.true
eq = (x**3 + x + 1)
assert [Eq(rootof(eq, i), j) for i in range(3) for j in solve(eq)
] == [False, False, True, False, True, False, True, False, False]
assert Eq(rootof(eq, 0), 1 + S.ImaginaryUnit) == False
def test_issue_15920():
r = rootof(x**5 - x + 1, 0)
p = Integral(x, (x, 1, y))
assert unchanged(Eq, r, p)
def test_CRootOf_subs():
assert rootof(x**3 + x + 1, 0).subs(x, y) == rootof(y**3 + y + 1, 0)
def test_CRootOf___new__():
assert rootof(x, 0) == 0
assert rootof(x, -1) == 0
assert rootof(x, S.Zero) == 0
assert rootof(x - 1, 0) == 1
assert rootof(x - 1, -1) == 1
assert rootof(x + 1, 0) == -1
assert rootof(x + 1, -1) == -1
assert rootof(x**2 + 2 * x + 3, 0) == -1 - I * sqrt(2)
assert rootof(x**2 + 2 * x + 3, 1) == -1 + I * sqrt(2)
assert rootof(x**2 + 2 * x + 3, -1) == -1 + I * sqrt(2)
assert rootof(x**2 + 2 * x + 3, -2) == -1 - I * sqrt(2)
r = rootof(x**2 + 2 * x + 3, 0, radicals=False)
assert isinstance(r, RootOf) is True
r = rootof(x**2 + 2 * x + 3, 1, radicals=False)
assert isinstance(r, RootOf) is True
r = rootof(x**2 + 2 * x + 3, -1, radicals=False)
assert isinstance(r, RootOf) is True
r = rootof(x**2 + 2 * x + 3, -2, radicals=False)
assert isinstance(r, RootOf) is True
assert rootof((x - 1) * (x + 1), 0, radicals=False) == -1
assert rootof((x - 1) * (x + 1), 1, radicals=False) == 1
assert rootof((x - 1) * (x + 1), -1, radicals=False) == 1
assert rootof((x - 1) * (x + 1), -2, radicals=False) == -1
assert rootof((x - 1) * (x + 1), 0, radicals=True) == -1
assert rootof((x - 1) * (x + 1), 1, radicals=True) == 1
assert rootof((x - 1) * (x + 1), -1, radicals=True) == 1
assert rootof((x - 1) * (x + 1), -2, radicals=True) == -1
assert rootof((x - 1) * (x**3 + x + 3), 0) == rootof(x**3 + x + 3, 0)
assert rootof((x - 1) * (x**3 + x + 3), 1) == 1
assert rootof((x - 1) * (x**3 + x + 3), 2) == rootof(x**3 + x + 3, 1)
assert rootof((x - 1) * (x**3 + x + 3), 3) == rootof(x**3 + x + 3, 2)
assert rootof((x - 1) * (x**3 + x + 3), -1) == rootof(x**3 + x + 3, 2)
assert rootof((x - 1) * (x**3 + x + 3), -2) == rootof(x**3 + x + 3, 1)
assert rootof((x - 1) * (x**3 + x + 3), -3) == 1
assert rootof((x - 1) * (x**3 + x + 3), -4) == rootof(x**3 + x + 3, 0)
assert rootof(x**4 + 3 * x**3, 0) == -3
assert rootof(x**4 + 3 * x**3, 1) == 0
assert rootof(x**4 + 3 * x**3, 2) == 0
assert rootof(x**4 + 3 * x**3, 3) == 0
raises(GeneratorsNeeded, lambda: rootof(0, 0))
raises(GeneratorsNeeded, lambda: rootof(1, 0))
raises(PolynomialError, lambda: rootof(Poly(0, x), 0))
raises(PolynomialError, lambda: rootof(Poly(1, x), 0))
raises(PolynomialError, lambda: rootof(x - y, 0))
raises(NotImplementedError, lambda: rootof(x**3 - x + sqrt(2), 0))
raises(NotImplementedError, lambda: rootof(x**3 - x + I, 0))
raises(IndexError, lambda: rootof(x**2 - 1, -4))
raises(IndexError, lambda: rootof(x**2 - 1, -3))
raises(IndexError, lambda: rootof(x**2 - 1, 2))
raises(IndexError, lambda: rootof(x**2 - 1, 3))
raises(ValueError, lambda: rootof(x**2 - 1, x))
assert rootof(Poly(x - y, x), 0) == y
assert rootof(Poly(x**2 - y, x), 0) == -sqrt(y)
assert rootof(Poly(x**2 - y, x), 1) == sqrt(y)
assert rootof(Poly(x**3 - y, x), 0) == y**Rational(1, 3)
assert rootof(y * x**3 + y * x + 2 * y, x, 0) == -1
raises(NotImplementedError, lambda: rootof(x**3 + x + 2 * y, x, 0))
assert rootof(x**3 + x + 1, 0).is_commutative is True
def test_CRootOf_diff():
assert rootof(x**3 + x + 1, 0).diff(x) == 0
assert rootof(x**3 + x + 1, 0).diff(y) == 0
def test_CRootOf_is_complex():
assert rootof(x**3 + x + 3, 0).is_complex is True
def test_CRootOf___eq__():
assert (rootof(x**3 + x + 3, 0) == rootof(x**3 + x + 3, 0)) is True
assert (rootof(x**3 + x + 3, 0) == rootof(x**3 + x + 3, 1)) is False
assert (rootof(x**3 + x + 3, 1) == rootof(x**3 + x + 3, 1)) is True
assert (rootof(x**3 + x + 3, 1) == rootof(x**3 + x + 3, 2)) is False
assert (rootof(x**3 + x + 3, 2) == rootof(x**3 + x + 3, 2)) is True
assert (rootof(x**3 + x + 3, 0) == rootof(y**3 + y + 3, 0)) is True
assert (rootof(x**3 + x + 3, 0) == rootof(y**3 + y + 3, 1)) is False
assert (rootof(x**3 + x + 3, 1) == rootof(y**3 + y + 3, 1)) is True
assert (rootof(x**3 + x + 3, 1) == rootof(y**3 + y + 3, 2)) is False
assert (rootof(x**3 + x + 3, 2) == rootof(y**3 + y + 3, 2)) is True
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_CRootOf_real_roots():
assert Poly(x**5 + x + 1).real_roots() == [rootof(x**3 - x**2 + 1, 0)]
assert Poly(x**5 + x + 1).real_roots(radicals=False) == [rootof(
x**3 - x**2 + 1, 0)]
def test_CRootOf_is_real():
assert rootof(x**3 + x + 3, 0).is_real is True
assert rootof(x**3 + x + 3, 1).is_real is False
assert rootof(x**3 + x + 3, 2).is_real is False
def test_CRootOf___new__():
assert rootof(x, 0) == 0
assert rootof(x, -1) == 0
assert rootof(x, S.Zero) == 0
assert rootof(x - 1, 0) == 1
assert rootof(x - 1, -1) == 1
assert rootof(x + 1, 0) == -1
assert rootof(x + 1, -1) == -1
assert rootof(x**2 + 2*x + 3, 0) == -1 - I*sqrt(2)
assert rootof(x**2 + 2*x + 3, 1) == -1 + I*sqrt(2)
assert rootof(x**2 + 2*x + 3, -1) == -1 + I*sqrt(2)
assert rootof(x**2 + 2*x + 3, -2) == -1 - I*sqrt(2)
r = rootof(x**2 + 2*x + 3, 0, radicals=False)
assert isinstance(r, RootOf) is True
r = rootof(x**2 + 2*x + 3, 1, radicals=False)
assert isinstance(r, RootOf) is True
r = rootof(x**2 + 2*x + 3, -1, radicals=False)
assert isinstance(r, RootOf) is True
r = rootof(x**2 + 2*x + 3, -2, radicals=False)
assert isinstance(r, RootOf) is True
assert rootof((x - 1)*(x + 1), 0, radicals=False) == -1
assert rootof((x - 1)*(x + 1), 1, radicals=False) == 1
assert rootof((x - 1)*(x + 1), -1, radicals=False) == 1
assert rootof((x - 1)*(x + 1), -2, radicals=False) == -1
assert rootof((x - 1)*(x + 1), 0, radicals=True) == -1
assert rootof((x - 1)*(x + 1), 1, radicals=True) == 1
assert rootof((x - 1)*(x + 1), -1, radicals=True) == 1
assert rootof((x - 1)*(x + 1), -2, radicals=True) == -1
assert rootof((x - 1)*(x**3 + x + 3), 0) == rootof(x**3 + x + 3, 0)
assert rootof((x - 1)*(x**3 + x + 3), 1) == 1
assert rootof((x - 1)*(x**3 + x + 3), 2) == rootof(x**3 + x + 3, 1)
assert rootof((x - 1)*(x**3 + x + 3), 3) == rootof(x**3 + x + 3, 2)
assert rootof((x - 1)*(x**3 + x + 3), -1) == rootof(x**3 + x + 3, 2)
assert rootof((x - 1)*(x**3 + x + 3), -2) == rootof(x**3 + x + 3, 1)
assert rootof((x - 1)*(x**3 + x + 3), -3) == 1
assert rootof((x - 1)*(x**3 + x + 3), -4) == rootof(x**3 + x + 3, 0)
assert rootof(x**4 + 3*x**3, 0) == -3
assert rootof(x**4 + 3*x**3, 1) == 0
assert rootof(x**4 + 3*x**3, 2) == 0
assert rootof(x**4 + 3*x**3, 3) == 0
raises(GeneratorsNeeded, lambda: rootof(0, 0))
raises(GeneratorsNeeded, lambda: rootof(1, 0))
raises(PolynomialError, lambda: rootof(Poly(0, x), 0))
raises(PolynomialError, lambda: rootof(Poly(1, x), 0))
raises(PolynomialError, lambda: rootof(x - y, 0))
# issue 8617
raises(PolynomialError, lambda: rootof(exp(x), 0))
raises(NotImplementedError, lambda: rootof(x**3 - x + sqrt(2), 0))
raises(NotImplementedError, lambda: rootof(x**3 - x + I, 0))
raises(IndexError, lambda: rootof(x**2 - 1, -4))
raises(IndexError, lambda: rootof(x**2 - 1, -3))
raises(IndexError, lambda: rootof(x**2 - 1, 2))
raises(IndexError, lambda: rootof(x**2 - 1, 3))
raises(ValueError, lambda: rootof(x**2 - 1, x))
assert rootof(Poly(x - y, x), 0) == y
assert rootof(Poly(x**2 - y, x), 0) == -sqrt(y)
assert rootof(Poly(x**2 - y, x), 1) == sqrt(y)
assert rootof(Poly(x**3 - y, x), 0) == y**Rational(1, 3)
assert rootof(y*x**3 + y*x + 2*y, x, 0) == -1
raises(NotImplementedError, lambda: rootof(x**3 + x + 2*y, x, 0))
assert rootof(x**3 + x + 1, 0).is_commutative is True
def test_CRootOf_evalf():
real = rootof(x**3 + x + 3, 0).evalf(n=20)
assert real.epsilon_eq(Float("-1.2134116627622296341"))
re, im = rootof(x**3 + x + 3, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq( Float("0.60670583138111481707"))
assert im.epsilon_eq(-Float("1.45061224918844152650"))
re, im = rootof(x**3 + x + 3, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("0.60670583138111481707"))
assert im.epsilon_eq(Float("1.45061224918844152650"))
p = legendre_poly(4, x, polys=True)
roots = [str(r.n(17)) for r in p.real_roots()]
# magnitudes are given by
# sqrt(3/S(7) - 2*sqrt(6/S(5))/7)
# and
# sqrt(3/S(7) + 2*sqrt(6/S(5))/7)
assert roots == [
"-0.86113631159405258",
"-0.33998104358485626",
"0.33998104358485626",
"0.86113631159405258",
]
re = rootof(x**5 - 5*x + 12, 0).evalf(n=20)
assert re.epsilon_eq(Float("-1.84208596619025438271"))
re, im = rootof(x**5 - 5*x + 12, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("-1.709561043370328882010"))
re, im = rootof(x**5 - 5*x + 12, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("+1.709561043370328882010"))
re, im = rootof(x**5 - 5*x + 12, 3).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("-0.719798681483861386681"))
re, im = rootof(x**5 - 5*x + 12, 4).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("+0.719798681483861386681"))
# issue 6393
assert str(rootof(x**5 + 2*x**4 + x**3 - 68719476736, 0).n(3)) == '147.'
eq = (531441*x**11 + 3857868*x**10 + 13730229*x**9 + 32597882*x**8 +
55077472*x**7 + 60452000*x**6 + 32172064*x**5 - 4383808*x**4 -
11942912*x**3 - 1506304*x**2 + 1453312*x + 512)
a, b = rootof(eq, 1).n(2).as_real_imag()
c, d = rootof(eq, 2).n(2).as_real_imag()
assert a == c
assert b < d
assert b == -d
# issue 6451
r = rootof(legendre_poly(64, x), 7)
assert r.n(2) == r.n(100).n(2)
# issue 9019
r0 = rootof(x**2 + 1, 0, radicals=False)
r1 = rootof(x**2 + 1, 1, radicals=False)
assert r0.n(4) == -1.0*I
assert r1.n(4) == 1.0*I
# make sure verification is used in case a max/min traps the "root"
assert str(rootof(4*x**5 + 16*x**3 + 12*x**2 + 7, 0).n(3)) == '-0.976'
# watch out for UnboundLocalError
c = CRootOf(90720*x**6 - 4032*x**4 + 84*x**2 - 1, 0)
assert c._eval_evalf(2) # doesn't fail
# watch out for imaginary parts that don't want to evaluate
assert str(RootOf(x**16 + 32*x**14 + 508*x**12 + 5440*x**10 +
39510*x**8 + 204320*x**6 + 755548*x**4 + 1434496*x**2 +
877969, 10).n(2)) == '-3.4*I'
assert abs(RootOf(x**4 + 10*x**2 + 1, 0).n(2)) < 0.4
# check reset and args
r = [RootOf(x**3 + x + 3, i) for i in range(3)]
r[0]._reset()
for ri in r:
i = ri._get_interval()
n = ri.n(2)
assert i != ri._get_interval()
ri._reset()
assert i == ri._get_interval()
assert i == i.func(*i.args)
def test_CRootOf_diff():
assert rootof(x**3 + x + 1, 0).diff(x) == 0
assert rootof(x**3 + x + 1, 0).diff(y) == 0
def test_minpoly_compose():
# issue 6868
eq = S('''
-1/(800*sqrt(-1/240 + 1/(18000*(-1/17280000 +
sqrt(15)*I/28800000)**(1/3)) + 2*(-1/17280000 +
sqrt(15)*I/28800000)**(1/3)))''')
mp = minimal_polynomial(eq + 3, x)
assert mp == 8000*x**2 - 48000*x + 71999
# issue 5888
assert minimal_polynomial(exp(I*pi/8), x) == x**8 + 1
mp = minimal_polynomial(sin(pi/7) + sqrt(2), x)
assert mp == 4096*x**12 - 63488*x**10 + 351488*x**8 - 826496*x**6 + \
770912*x**4 - 268432*x**2 + 28561
mp = minimal_polynomial(cos(pi/7) + sqrt(2), x)
assert mp == 64*x**6 - 64*x**5 - 432*x**4 + 304*x**3 + 712*x**2 - \
232*x - 239
mp = minimal_polynomial(exp(I*pi/7) + sqrt(2), x)
assert mp == x**12 - 2*x**11 - 9*x**10 + 16*x**9 + 43*x**8 - 70*x**7 - 97*x**6 + 126*x**5 + 211*x**4 - 212*x**3 - 37*x**2 + 142*x + 127
mp = minimal_polynomial(sin(pi/7) + sqrt(2), x)
assert mp == 4096*x**12 - 63488*x**10 + 351488*x**8 - 826496*x**6 + \
770912*x**4 - 268432*x**2 + 28561
mp = minimal_polynomial(cos(pi/7) + sqrt(2), x)
assert mp == 64*x**6 - 64*x**5 - 432*x**4 + 304*x**3 + 712*x**2 - \
232*x - 239
mp = minimal_polynomial(exp(I*pi/7) + sqrt(2), x)
assert mp == x**12 - 2*x**11 - 9*x**10 + 16*x**9 + 43*x**8 - 70*x**7 - 97*x**6 + 126*x**5 + 211*x**4 - 212*x**3 - 37*x**2 + 142*x + 127
mp = minimal_polynomial(exp(2*I*pi/7), x)
assert mp == x**6 + x**5 + x**4 + x**3 + x**2 + x + 1
mp = minimal_polynomial(exp(2*I*pi/15), x)
assert mp == x**8 - x**7 + x**5 - x**4 + x**3 - x + 1
mp = minimal_polynomial(cos(2*pi/7), x)
assert mp == 8*x**3 + 4*x**2 - 4*x - 1
mp = minimal_polynomial(sin(2*pi/7), x)
ex = (5*cos(2*pi/7) - 7)/(9*cos(pi/7) - 5*cos(3*pi/7))
mp = minimal_polynomial(ex, x)
assert mp == x**3 + 2*x**2 - x - 1
assert minimal_polynomial(-1/(2*cos(pi/7)), x) == x**3 + 2*x**2 - x - 1
assert minimal_polynomial(sin(2*pi/15), x) == \
256*x**8 - 448*x**6 + 224*x**4 - 32*x**2 + 1
assert minimal_polynomial(sin(5*pi/14), x) == 8*x**3 - 4*x**2 - 4*x + 1
assert minimal_polynomial(cos(pi/15), x) == 16*x**4 + 8*x**3 - 16*x**2 - 8*x + 1
ex = rootof(x**3 +x*4 + 1, 0)
mp = minimal_polynomial(ex, x)
assert mp == x**3 + 4*x + 1
mp = minimal_polynomial(ex + 1, x)
assert mp == x**3 - 3*x**2 + 7*x - 4
assert minimal_polynomial(exp(I*pi/3), x) == x**2 - x + 1
assert minimal_polynomial(exp(I*pi/4), x) == x**4 + 1
assert minimal_polynomial(exp(I*pi/6), x) == x**4 - x**2 + 1
assert minimal_polynomial(exp(I*pi/9), x) == x**6 - x**3 + 1
assert minimal_polynomial(exp(I*pi/10), x) == x**8 - x**6 + x**4 - x**2 + 1
assert minimal_polynomial(sin(pi/9), x) == 64*x**6 - 96*x**4 + 36*x**2 - 3
assert minimal_polynomial(sin(pi/11), x) == 1024*x**10 - 2816*x**8 + \
2816*x**6 - 1232*x**4 + 220*x**2 - 11
ex = 2**Rational(1, 3)*exp(Rational(2, 3)*I*pi)
assert minimal_polynomial(ex, x) == x**3 - 2
raises(NotAlgebraic, lambda: minimal_polynomial(cos(pi*sqrt(2)), x))
raises(NotAlgebraic, lambda: minimal_polynomial(sin(pi*sqrt(2)), x))
raises(NotAlgebraic, lambda: minimal_polynomial(exp(I*pi*sqrt(2)), x))
# issue 5934
ex = 1/(-36000 - 7200*sqrt(5) + (12*sqrt(10)*sqrt(sqrt(5) + 5) +
24*sqrt(10)*sqrt(-sqrt(5) + 5))**2) + 1
raises(ZeroDivisionError, lambda: minimal_polynomial(ex, x))
ex = sqrt(1 + 2**Rational(1,3)) + sqrt(1 + 2**Rational(1,4)) + sqrt(2)
mp = minimal_polynomial(ex, x)
assert degree(mp) == 48 and mp.subs({x:0}) == -16630256576
def test_slow_general_univariate():
r = rootof(x**5 - x**2 + 1, 0)
assert solve(sqrt(x) + 1/root(x, 3) > 1) == \
Or(And(S(0) < x, x < r**6), And(r**6 < x, x < oo))
def test_CRootOf_evalf():
real = rootof(x**3 + x + 3, 0).evalf(n=20)
assert real.epsilon_eq(Float("-1.2134116627622296341"))
re, im = rootof(x**3 + x + 3, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq( Float("0.60670583138111481707"))
assert im.epsilon_eq(-Float("1.45061224918844152650"))
re, im = rootof(x**3 + x + 3, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("0.60670583138111481707"))
assert im.epsilon_eq(Float("1.45061224918844152650"))
p = legendre_poly(4, x, polys=True)
roots = [str(r.n(17)) for r in p.real_roots()]
assert roots == [
"-0.86113631159405258",
"-0.33998104358485626",
"0.33998104358485626",
"0.86113631159405258",
]
re = rootof(x**5 - 5*x + 12, 0).evalf(n=20)
assert re.epsilon_eq(Float("-1.84208596619025438271"))
re, im = rootof(x**5 - 5*x + 12, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("-1.709561043370328882010"))
re, im = rootof(x**5 - 5*x + 12, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("+1.709561043370328882010"))
re, im = rootof(x**5 - 5*x + 12, 3).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("-0.719798681483861386681"))
re, im = rootof(x**5 - 5*x + 12, 4).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("+0.719798681483861386681"))
# issue 6393
assert str(rootof(x**5 + 2*x**4 + x**3 - 68719476736, 0).n(3)) == '147.'
eq = (531441*x**11 + 3857868*x**10 + 13730229*x**9 + 32597882*x**8 +
55077472*x**7 + 60452000*x**6 + 32172064*x**5 - 4383808*x**4 -
11942912*x**3 - 1506304*x**2 + 1453312*x + 512)
a, b = rootof(eq, 1).n(2).as_real_imag()
c, d = rootof(eq, 2).n(2).as_real_imag()
assert a == c
assert b < d
assert b == -d
# issue 6451
r = rootof(legendre_poly(64, x), 7)
assert r.n(2) == r.n(100).n(2)
# issue 8617
ans = [w.n(2) for w in solve(x**3 - x - 4)]
assert rootof(exp(x)**3 - exp(x) - 4, 0).n(2) in ans
# issue 9019
r0 = rootof(x**2 + 1, 0, radicals=False)
r1 = rootof(x**2 + 1, 1, radicals=False)
assert r0.n(4) == -1.0*I
assert r1.n(4) == 1.0*I
# make sure verification is used in case a max/min traps the "root"
assert str(rootof(4*x**5 + 16*x**3 + 12*x**2 + 7, 0).n(3)) == '-0.976'
def test_CRootOf_is_real():
assert rootof(x**3 + x + 3, 0).is_real is True
assert rootof(x**3 + x + 3, 1).is_real is False
assert rootof(x**3 + x + 3, 2).is_real is False
def test_issue_15920():
r = rootof(x**5 - x + 1, 0)
p = Integral(x, (x, 1, y))
assert Eq(r, p).lhs is r and Eq(r, p).rhs is p
def test_CRootOf_subs():
assert rootof(x**3 + x + 1, 0).subs(x, y) == rootof(y**3 + y + 1, 0)
def test_CRootOf___eq__():
assert (rootof(x**3 + x + 3, 0) == rootof(x**3 + x + 3, 0)) is True
assert (rootof(x**3 + x + 3, 0) == rootof(x**3 + x + 3, 1)) is False
assert (rootof(x**3 + x + 3, 1) == rootof(x**3 + x + 3, 1)) is True
assert (rootof(x**3 + x + 3, 1) == rootof(x**3 + x + 3, 2)) is False
assert (rootof(x**3 + x + 3, 2) == rootof(x**3 + x + 3, 2)) is True
assert (rootof(x**3 + x + 3, 0) == rootof(y**3 + y + 3, 0)) is True
assert (rootof(x**3 + x + 3, 0) == rootof(y**3 + y + 3, 1)) is False
assert (rootof(x**3 + x + 3, 1) == rootof(y**3 + y + 3, 1)) is True
assert (rootof(x**3 + x + 3, 1) == rootof(y**3 + y + 3, 2)) is False
assert (rootof(x**3 + x + 3, 2) == rootof(y**3 + y + 3, 2)) is True
def test_CRootOf_evalf():
real = rootof(x**3 + x + 3, 0).evalf(n=20)
assert real.epsilon_eq(Float("-1.2134116627622296341"))
re, im = rootof(x**3 + x + 3, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("0.60670583138111481707"))
assert im.epsilon_eq(-Float("1.45061224918844152650"))
re, im = rootof(x**3 + x + 3, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("0.60670583138111481707"))
assert im.epsilon_eq(Float("1.45061224918844152650"))
p = legendre_poly(4, x, polys=True)
roots = [str(r.n(17)) for r in p.real_roots()]
# magnitudes are given by
# sqrt(3/S(7) - 2*sqrt(6/S(5))/7)
# and
# sqrt(3/S(7) + 2*sqrt(6/S(5))/7)
assert roots == [
"-0.86113631159405258",
"-0.33998104358485626",
"0.33998104358485626",
"0.86113631159405258",
]
re = rootof(x**5 - 5 * x + 12, 0).evalf(n=20)
assert re.epsilon_eq(Float("-1.84208596619025438271"))
re, im = rootof(x**5 - 5 * x + 12, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("-1.709561043370328882010"))
re, im = rootof(x**5 - 5 * x + 12, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("+1.709561043370328882010"))
re, im = rootof(x**5 - 5 * x + 12, 3).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("-0.719798681483861386681"))
re, im = rootof(x**5 - 5 * x + 12, 4).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("+0.719798681483861386681"))
# issue 6393
assert str(rootof(x**5 + 2 * x**4 + x**3 - 68719476736, 0).n(3)) == '147.'
eq = (531441 * x**11 + 3857868 * x**10 + 13730229 * x**9 +
32597882 * x**8 + 55077472 * x**7 + 60452000 * x**6 +
32172064 * x**5 - 4383808 * x**4 - 11942912 * x**3 - 1506304 * x**2 +
1453312 * x + 512)
a, b = rootof(eq, 1).n(2).as_real_imag()
c, d = rootof(eq, 2).n(2).as_real_imag()
assert a == c
assert b < d
assert b == -d
# issue 6451
r = rootof(legendre_poly(64, x), 7)
assert r.n(2) == r.n(100).n(2)
# issue 8617
ans = [w.n(2) for w in solve(x**3 - x - 4)]
assert rootof(exp(x)**3 - exp(x) - 4, 0).n(2) in ans
# issue 9019
r0 = rootof(x**2 + 1, 0, radicals=False)
r1 = rootof(x**2 + 1, 1, radicals=False)
assert r0.n(4) == -1.0 * I
assert r1.n(4) == 1.0 * I
# make sure verification is used in case a max/min traps the "root"
assert str(rootof(4 * x**5 + 16 * x**3 + 12 * x**2 + 7,
0).n(3)) == '-0.976'
# watch out for UnboundLocalError
c = CRootOf(90720 * x**6 - 4032 * x**4 + 84 * x**2 - 1, 0)
assert c._eval_evalf(2) # doesn't fail
# watch out for imaginary parts that don't want to evaluate
assert str(
RootOf(
x**16 + 32 * x**14 + 508 * x**12 + 5440 * x**10 + 39510 * x**8 +
204320 * x**6 + 755548 * x**4 + 1434496 * x**2 + 877969,
10).n(2)) == '-3.4*I'
assert abs(RootOf(x**4 + 10 * x**2 + 1, 0).n(2)) < 0.4
# check reset and args
r = [RootOf(x**3 + x + 3, i) for i in range(3)]
r[0]._reset()
for ri in r:
i = ri._get_interval()
n = ri.n(2)
assert i != ri._get_interval()
ri._reset()
assert i == ri._get_interval()
assert i == i.func(*i.args)
def test_CRootOf_evalf():
real = rootof(x**3 + x + 3, 0).evalf(n=20)
assert real.epsilon_eq(Float("-1.2134116627622296341"))
re, im = rootof(x**3 + x + 3, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("0.60670583138111481707"))
assert im.epsilon_eq(-Float("1.45061224918844152650"))
re, im = rootof(x**3 + x + 3, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("0.60670583138111481707"))
assert im.epsilon_eq(Float("1.45061224918844152650"))
p = legendre_poly(4, x, polys=True)
roots = [str(r.n(17)) for r in p.real_roots()]
assert roots == [
"-0.86113631159405258",
"-0.33998104358485626",
"0.33998104358485626",
"0.86113631159405258",
]
re = rootof(x**5 - 5 * x + 12, 0).evalf(n=20)
assert re.epsilon_eq(Float("-1.84208596619025438271"))
re, im = rootof(x**5 - 5 * x + 12, 1).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("-1.709561043370328882010"))
re, im = rootof(x**5 - 5 * x + 12, 2).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("-0.351854240827371999559"))
assert im.epsilon_eq(Float("+1.709561043370328882010"))
re, im = rootof(x**5 - 5 * x + 12, 3).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("-0.719798681483861386681"))
re, im = rootof(x**5 - 5 * x + 12, 4).evalf(n=20).as_real_imag()
assert re.epsilon_eq(Float("+1.272897223922499190910"))
assert im.epsilon_eq(Float("+0.719798681483861386681"))
# issue 6393
assert str(rootof(x**5 + 2 * x**4 + x**3 - 68719476736, 0).n(3)) == '147.'
eq = (531441 * x**11 + 3857868 * x**10 + 13730229 * x**9 +
32597882 * x**8 + 55077472 * x**7 + 60452000 * x**6 +
32172064 * x**5 - 4383808 * x**4 - 11942912 * x**3 - 1506304 * x**2 +
1453312 * x + 512)
a, b = rootof(eq, 1).n(2).as_real_imag()
c, d = rootof(eq, 2).n(2).as_real_imag()
assert a == c
assert b < d
assert b == -d
# issue 6451
r = rootof(legendre_poly(64, x), 7)
assert r.n(2) == r.n(100).n(2)
# issue 8617
ans = [w.n(2) for w in solve(x**3 - x - 4)]
assert rootof(exp(x)**3 - exp(x) - 4, 0).n(2) in ans
# issue 9019
r0 = rootof(x**2 + 1, 0, radicals=False)
r1 = rootof(x**2 + 1, 1, radicals=False)
assert r0.n(4) == -1.0 * I
assert r1.n(4) == 1.0 * I
# make sure verification is used in case a max/min traps the "root"
assert str(rootof(4 * x**5 + 16 * x**3 + 12 * x**2 + 7,
0).n(3)) == '-0.976'
# watch out for UnboundLocalError
c = CRootOf(90720 * x**6 - 4032 * x**4 + 84 * x**2 - 1, 0)
assert str(c._eval_evalf(2)) == '-0.e-1'
def test_CRootOf_real_roots():
assert Poly(x**5 + x + 1).real_roots() == [rootof(x**3 - x**2 + 1, 0)]
assert Poly(x**5 + x +
1).real_roots(radicals=False) == [rootof(x**3 - x**2 + 1, 0)]
def test_CRootOf_is_complex():
assert rootof(x**3 + x + 3, 0).is_complex is True
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_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_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_minpoly_compose():
# issue 6868
eq = S('''
-1/(800*sqrt(-1/240 + 1/(18000*(-1/17280000 +
sqrt(15)*I/28800000)**(1/3)) + 2*(-1/17280000 +
sqrt(15)*I/28800000)**(1/3)))''')
mp = minimal_polynomial(eq + 3, x)
assert mp == 8000*x**2 - 48000*x + 71999
# issue 5888
assert minimal_polynomial(exp(I*pi/8), x) == x**8 + 1
mp = minimal_polynomial(sin(pi/7) + sqrt(2), x)
assert mp == 4096*x**12 - 63488*x**10 + 351488*x**8 - 826496*x**6 + \
770912*x**4 - 268432*x**2 + 28561
mp = minimal_polynomial(cos(pi/7) + sqrt(2), x)
assert mp == 64*x**6 - 64*x**5 - 432*x**4 + 304*x**3 + 712*x**2 - \
232*x - 239
mp = minimal_polynomial(exp(I*pi/7) + sqrt(2), x)
assert mp == x**12 - 2*x**11 - 9*x**10 + 16*x**9 + 43*x**8 - 70*x**7 - 97*x**6 + 126*x**5 + 211*x**4 - 212*x**3 - 37*x**2 + 142*x + 127
mp = minimal_polynomial(sin(pi/7) + sqrt(2), x)
assert mp == 4096*x**12 - 63488*x**10 + 351488*x**8 - 826496*x**6 + \
770912*x**4 - 268432*x**2 + 28561
mp = minimal_polynomial(cos(pi/7) + sqrt(2), x)
assert mp == 64*x**6 - 64*x**5 - 432*x**4 + 304*x**3 + 712*x**2 - \
232*x - 239
mp = minimal_polynomial(exp(I*pi/7) + sqrt(2), x)
assert mp == x**12 - 2*x**11 - 9*x**10 + 16*x**9 + 43*x**8 - 70*x**7 - 97*x**6 + 126*x**5 + 211*x**4 - 212*x**3 - 37*x**2 + 142*x + 127
mp = minimal_polynomial(exp(2*I*pi/7), x)
assert mp == x**6 + x**5 + x**4 + x**3 + x**2 + x + 1
mp = minimal_polynomial(exp(2*I*pi/15), x)
assert mp == x**8 - x**7 + x**5 - x**4 + x**3 - x + 1
mp = minimal_polynomial(cos(2*pi/7), x)
assert mp == 8*x**3 + 4*x**2 - 4*x - 1
mp = minimal_polynomial(sin(2*pi/7), x)
ex = (5*cos(2*pi/7) - 7)/(9*cos(pi/7) - 5*cos(3*pi/7))
mp = minimal_polynomial(ex, x)
assert mp == x**3 + 2*x**2 - x - 1
assert minimal_polynomial(-1/(2*cos(pi/7)), x) == x**3 + 2*x**2 - x - 1
assert minimal_polynomial(sin(2*pi/15), x) == \
256*x**8 - 448*x**6 + 224*x**4 - 32*x**2 + 1
assert minimal_polynomial(sin(5*pi/14), x) == 8*x**3 - 4*x**2 - 4*x + 1
assert minimal_polynomial(cos(pi/15), x) == 16*x**4 + 8*x**3 - 16*x**2 - 8*x + 1
ex = rootof(x**3 +x*4 + 1, 0)
mp = minimal_polynomial(ex, x)
assert mp == x**3 + 4*x + 1
mp = minimal_polynomial(ex + 1, x)
assert mp == x**3 - 3*x**2 + 7*x - 4
assert minimal_polynomial(exp(I*pi/3), x) == x**2 - x + 1
assert minimal_polynomial(exp(I*pi/4), x) == x**4 + 1
assert minimal_polynomial(exp(I*pi/6), x) == x**4 - x**2 + 1
assert minimal_polynomial(exp(I*pi/9), x) == x**6 - x**3 + 1
assert minimal_polynomial(exp(I*pi/10), x) == x**8 - x**6 + x**4 - x**2 + 1
assert minimal_polynomial(sin(pi/9), x) == 64*x**6 - 96*x**4 + 36*x**2 - 3
assert minimal_polynomial(sin(pi/11), x) == 1024*x**10 - 2816*x**8 + \
2816*x**6 - 1232*x**4 + 220*x**2 - 11
ex = 2**Rational(1, 3)*exp(Rational(2, 3)*I*pi)
assert minimal_polynomial(ex, x) == x**3 - 2
raises(NotAlgebraic, lambda: minimal_polynomial(cos(pi*sqrt(2)), x))
raises(NotAlgebraic, lambda: minimal_polynomial(sin(pi*sqrt(2)), x))
raises(NotAlgebraic, lambda: minimal_polynomial(exp(I*pi*sqrt(2)), x))
# issue 5934
ex = 1/(-36000 - 7200*sqrt(5) + (12*sqrt(10)*sqrt(sqrt(5) + 5) +
24*sqrt(10)*sqrt(-sqrt(5) + 5))**2) + 1
raises(ZeroDivisionError, lambda: minimal_polynomial(ex, x))
ex = sqrt(1 + 2**Rational(1,3)) + sqrt(1 + 2**Rational(1,4)) + sqrt(2)
mp = minimal_polynomial(ex, x)
assert degree(mp) == 48 and mp.subs({x:0}) == -16630256576
def test_slow_general_univariate():
r = rootof(x**5 - x**2 + 1, 0)
assert solve(sqrt(x) + 1/root(x, 3) > 1) == \
Or(And(S(0) < x, x < r**6), And(r**6 < x, x < oo))
def test_issue_15920():
r = rootof(x**5 - x + 1, 0)
p = Integral(x, (x, 1, y))
assert unchanged(Eq, r, p)
