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_8545():
from sympy import refine
eq = 1 - x - abs(1 - x)
ans = And(Lt(1, x), Lt(x, oo))
assert reduce_abs_inequality(eq, '<', x) == ans
eq = 1 - x - sqrt((1 - x)**2)
assert reduce_inequalities(refine(eq) < 0) == ans
def test_inequality_no_auto_simplify():
# no simplify on creation but can be simplified
lhs = cos(x)**2 + sin(x)**2
rhs = 2
e = Lt(lhs, rhs)
assert e == Lt(lhs, rhs, evaluate=False)
assert simplify(e)
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.Half, True, True),
Interval(S.Half + 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.One < 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_reduce_inequalities_multivariate():
x = Symbol('x')
y = Symbol('y')
assert reduce_inequalities([Ge(x**2, 1), Ge(y**2, 1)]) == \
And(Eq(im(x), 0), Eq(im(y), 0), Or(And(Le(1, re(x)), Lt(re(x), oo)),
And(Le(re(x), -1), Lt(-oo, re(x)))),
Or(And(Le(1, re(y)), Lt(re(y), oo)), And(Le(re(y), -1), Lt(-oo, re(y)))))
def test_solve_inequalities():
system = [Lt(x**2 - 2, 0), Gt(x**2 - 1, 0)]
assert solve(system) == \
And(Or(And(Lt(-sqrt(2), re(x)), Lt(re(x), -1)),
And(Lt(1, re(x)), Lt(re(x), sqrt(2)))), Eq(im(x), 0))
assert solve(system, assume=Q.real(x)) == \
Or(And(Lt(-sqrt(2), x), Lt(x, -1)), And(Lt(1, x), Lt(x, sqrt(2))))
def test_reduce_abs_inequalities():
real = Q.real(x)
assert reduce_inequalities(
abs(x - 5) < 3, assume=real) == And(Lt(2, x), Lt(x, 8))
assert reduce_inequalities(
abs(2*x + 3) >= 8, assume=real) == Or(Le(x, -S(11)/2), Ge(x, S(5)/2))
assert reduce_inequalities(abs(x - 4) + abs(
3*x - 5) < 7, assume=real) == And(Lt(S(1)/2, x), Lt(x, 4))
assert reduce_inequalities(abs(x - 4) + abs(3*abs(x) - 5) < 7, assume=real) == Or(And(S(-2) < x, x < -1), And(S(1)/2 < x, x < 4))
raises(NotImplementedError, lambda: reduce_inequalities(abs(x - 5) < 3))
def test_Infinity_inequations():
assert oo > pi
assert not (oo < pi)
assert exp(-3) < oo
assert Float('+inf') > pi
assert not (Float('+inf') < pi)
assert exp(-3) < Float('+inf')
raises(TypeError, lambda: oo < I)
raises(TypeError, lambda: oo <= I)
raises(TypeError, lambda: oo > I)
raises(TypeError, lambda: oo >= I)
raises(TypeError, lambda: -oo < I)
raises(TypeError, lambda: -oo <= I)
raises(TypeError, lambda: -oo > I)
raises(TypeError, lambda: -oo >= I)
raises(TypeError, lambda: I < oo)
raises(TypeError, lambda: I <= oo)
raises(TypeError, lambda: I > oo)
raises(TypeError, lambda: I >= oo)
raises(TypeError, lambda: I < -oo)
raises(TypeError, lambda: I <= -oo)
raises(TypeError, lambda: I > -oo)
raises(TypeError, lambda: I >= -oo)
assert oo > -oo and oo >= -oo
assert (oo < -oo) == False and (oo <= -oo) == False
assert -oo < oo and -oo <= oo
assert (-oo > oo) == False and (-oo >= oo) == False
assert (oo < oo) == False # issue 7775
assert (oo > oo) == False
assert (-oo > -oo) == False and (-oo < -oo) == False
assert oo >= oo and oo <= oo and -oo >= -oo and -oo <= -oo
assert (-oo < -Float('inf')) == False
assert (oo > Float('inf')) == False
assert -oo >= -Float('inf')
assert oo <= Float('inf')
x = Symbol('x')
b = Symbol('b', finite=True, real=True)
assert (x < oo) == Lt(x, oo) # issue 7775
assert b < oo and b > -oo and b <= oo and b >= -oo
assert oo > b and oo >= b and (oo < b) == False and (oo <= b) == False
assert (-oo > b) == False and (-oo >= b) == False and -oo < b and -oo <= b
assert (oo < x) == Lt(oo, x) and (oo > x) == Gt(oo, x)
assert (oo <= x) == Le(oo, x) and (oo >= x) == Ge(oo, x)
assert (-oo < x) == Lt(-oo, x) and (-oo > x) == Gt(-oo, x)
assert (-oo <= x) == Le(-oo, x) and (-oo >= x) == Ge(-oo, x)
def _visit_ComparisonNode(self, stmt):
first = self._visit(stmt.first)
second = self._visit(stmt.second)
op = stmt.value.first
if op == '==':
return Eq(first, second, evaluate=False)
elif op == '!=':
return Ne(first, second, evaluate=False)
elif op == '<':
return Lt(first, second, evaluate=False)
elif op == '>':
return Gt(first, second, evaluate=False)
elif op == '<=':
return Le(first, second, evaluate=False)
elif op == '>=':
return Ge(first, second, evaluate=False)
elif op == 'is':
return Is(first, second)
else:
msg = 'unknown/unavailable binary operator {node}'
msg = msg.format(node=type(op))
raise PyccelSyntaxError(msg)
def test_relational_noncommutative():
from sympy import Lt, Gt, Le, Ge
A, B = symbols('A,B', commutative=False)
assert (A < B) == Lt(A, B)
assert (A <= B) == Le(A, B)
assert (A > B) == Gt(A, B)
assert (A >= B) == Ge(A, B)
def test_relational_noncommutative():
from sympy import Lt, Gt, Le, Ge
a, b = symbols('a b', commutative=False)
assert (a < b) == Lt(a, b)
assert (a <= b) == Le(a, b)
assert (a > b) == Gt(a, b)
assert (a >= b) == Ge(a, b)
def test_mathml_relational():
mml_1 = mp._print(Eq(x, 1))
assert mml_1.nodeName == 'apply'
assert mml_1.childNodes[0].nodeName == 'eq'
assert mml_1.childNodes[1].nodeName == 'ci'
assert mml_1.childNodes[1].childNodes[0].nodeValue == 'x'
assert mml_1.childNodes[2].nodeName == 'cn'
assert mml_1.childNodes[2].childNodes[0].nodeValue == '1'
mml_2 = mp._print(Ne(1, x))
assert mml_2.nodeName == 'apply'
assert mml_2.childNodes[0].nodeName == 'neq'
assert mml_2.childNodes[1].nodeName == 'cn'
assert mml_2.childNodes[1].childNodes[0].nodeValue == '1'
assert mml_2.childNodes[2].nodeName == 'ci'
assert mml_2.childNodes[2].childNodes[0].nodeValue == 'x'
mml_3 = mp._print(Ge(1, x))
assert mml_3.nodeName == 'apply'
assert mml_3.childNodes[0].nodeName == 'leq'
assert mml_3.childNodes[1].nodeName == 'ci'
assert mml_3.childNodes[1].childNodes[0].nodeValue == 'x'
assert mml_3.childNodes[2].nodeName == 'cn'
assert mml_3.childNodes[2].childNodes[0].nodeValue == '1'
mml_4 = mp._print(Lt(1, x))
assert mml_4.nodeName == 'apply'
assert mml_4.childNodes[0].nodeName == 'lt'
assert mml_4.childNodes[1].nodeName == 'cn'
assert mml_4.childNodes[1].childNodes[0].nodeValue == '1'
assert mml_4.childNodes[2].nodeName == 'ci'
assert mml_4.childNodes[2].childNodes[0].nodeValue == 'x'
def test_ccode_Relational():
from sympy import Eq, Ne, Le, Lt, Gt, Ge
assert ccode(Eq(x, y)) == "x == y"
assert ccode(Ne(x, y)) == "x != y"
assert ccode(Le(x, y)) == "x <= y"
assert ccode(Lt(x, y)) == "x < y"
assert ccode(Gt(x, y)) == "x > y"
assert ccode(Ge(x, y)) == "x >= y"
def test_solve_univariate_inequality():
x = Symbol('x', real=True)
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)
def test_python_relational():
assert python(Eq(x, y)) == "x = Symbol('x')\ny = Symbol('y')\ne = x == y"
assert python(Ge(x, y)) == "x = Symbol('x')\ny = Symbol('y')\ne = x >= y"
assert python(Le(x, y)) == "x = Symbol('x')\ny = Symbol('y')\ne = x <= y"
assert python(Gt(x, y)) == "x = Symbol('x')\ny = Symbol('y')\ne = x > y"
assert python(Lt(x, y)) == "x = Symbol('x')\ny = Symbol('y')\ne = x < y"
assert python(Ne(x/(y + 1), y**2)) in [
"x = Symbol('x')\ny = Symbol('y')\ne = x/(1 + y) != y**2",
"x = Symbol('x')\ny = Symbol('y')\ne = x/(y + 1) != y**2"]
def test_Interval_as_relational():
x = Symbol('x')
assert Interval(-1, 2, False, False).as_relational(x) == \
And(Le(-1, x), Le(x, 2))
assert Interval(-1, 2, True, False).as_relational(x) == \
And(Lt(-1, x), Le(x, 2))
assert Interval(-1, 2, False, True).as_relational(x) == \
And(Le(-1, x), Lt(x, 2))
assert Interval(-1, 2, True, True).as_relational(x) == \
And(Lt(-1, x), Lt(x, 2))
assert Interval(-oo, 2, right_open=False).as_relational(x) == Le(x, 2)
assert Interval(-oo, 2, right_open=True).as_relational(x) == Lt(x, 2)
assert Interval(-2, oo, left_open=False).as_relational(x) == Ge(x, -2)
assert Interval(-2, oo, left_open=True).as_relational(x) == Gt(x, -2)
assert Interval(-oo, oo).as_relational(x) is True
def init():
# FIXME: Are (+-)oo correctly handled?
Expr.__add__ = \
lambda s, e: Expr(apply_and_simplify(s.expr, e.expr, operator.add))
Expr.__sub__ = \
lambda s, e: Expr(apply_and_simplify(s.expr, e.expr, operator.sub))
Expr.__mul__ = \
lambda s, e: Expr(apply_and_simplify(s.expr, e.expr, operator.mul, \
invert_on_negative=True))
Expr.__div__ = \
lambda s, e: Expr(apply_and_simplify(s.expr, e.expr, operator.div, \
invert_on_negative=True))
Expr.__pow__ = lambda s, e: Expr(s.expr ** e.expr)
Expr.__neg__ = lambda s: Expr(-s.expr)
Expr.__eq__ = lambda s, e: Expr(Eq(s.expr, e.expr))
Expr.__ne__ = lambda s, e: Expr(Ne(s.expr, e.expr))
Expr.__lt__ = lambda s, e: Expr(Lt(s.expr, e.expr))
Expr.__le__ = lambda s, e: Expr(Le(s.expr, e.expr))
Expr.__gt__ = lambda s, e: Expr(Gt(s.expr, e.expr))
Expr.__ge__ = lambda s, e: Expr(Ge(s.expr, e.expr))
Expr.__and__ = lambda s, e: Expr(And(s.expr, e.expr))
Expr.__or__ = lambda s, e: Expr(Or(s.expr, e.expr))
Expr.__invert__ = lambda s: Expr(Not(s.expr))
Expr.is_eq = lambda s, e: s.expr == e.expr
Expr.is_ne = lambda s, e: s.expr != e.expr
Expr.is_empty = lambda s: s.is_eq(Expr.empty)
Expr.is_inf = lambda s: s.expr == S.Infinity or s.expr == -S.Infinity
Expr.is_plus_inf = lambda s: s.expr == S.Infinity
Expr.is_minus_inf = lambda s: s.expr == -S.Infinity
Expr.is_constant = lambda s: isinstance(s.expr, Integer)
Expr.is_integer = lambda s: isinstance(s.expr, Integer)
Expr.is_rational = lambda s: isinstance(s.expr, Rational)
Expr.is_symbol = lambda s: isinstance(s.expr, Symbol)
Expr.is_min = lambda s: isinstance(s.expr, Min)
Expr.is_max = lambda s: isinstance(s.expr, Max)
Expr.is_add = lambda s: isinstance(s.expr, Add)
Expr.is_mul = lambda s: isinstance(s.expr, Mul)
Expr.is_pow = lambda s: isinstance(s.expr, Pow)
Expr.get_integer = lambda s: s.expr.p
Expr.get_numer = lambda s: s.expr.p
Expr.get_denom = lambda s: s.expr.q
Expr.get_name = lambda s: s.expr.name
Expr.compare = lambda s, e: s.compare(e)
# Empty. When min/max is invalid.
Expr.empty = Expr("EMPTY")
def test_While():
xpp = AddAugmentedAssignment(x, 1)
whl1 = While(x < 2, [xpp])
assert whl1.condition.args[0] == x
assert whl1.condition.args[1] == 2
assert whl1.condition == Lt(x, 2, evaluate=False)
assert whl1.body.args == (xpp, )
assert whl1.func(*whl1.args) == whl1
cblk = CodeBlock(AddAugmentedAssignment(x, 1))
whl2 = While(x < 2, cblk)
assert whl1 == whl2
assert whl1 != While(x < 3, [xpp])
def test_reduce_poly_inequalities_complex_relational():
cond = Eq(im(x), 0)
assert reduce_poly_inequalities([[Eq(x**2, 0)]], x, relational=True) == And(Eq(re(x), 0), cond)
assert reduce_poly_inequalities([[Le(x**2, 0)]], x, relational=True) == And(Eq(re(x), 0), cond)
assert reduce_poly_inequalities([[Lt(x**2, 0)]], x, relational=True) == False
assert reduce_poly_inequalities([[Ge(x**2, 0)]], x, relational=True) == cond
assert reduce_poly_inequalities([[Gt(x**2, 0)]], x, relational=True) == And(Or(Lt(re(x), 0), Lt(0, re(x))), cond)
assert reduce_poly_inequalities([[Ne(x**2, 0)]], x, relational=True) == And(Or(Lt(re(x), 0), Lt(0, re(x))), cond)
assert reduce_poly_inequalities([[Eq(x**2, 1)]], x, relational=True) == And(Or(Eq(re(x), -1), Eq(re(x), 1)), cond)
assert reduce_poly_inequalities([[Le(x**2, 1)]], x, relational=True) == And(And(Le(-1, re(x)), Le(re(x), 1)), cond)
assert reduce_poly_inequalities([[Lt(x**2, 1)]], x, relational=True) == And(And(Lt(-1, re(x)), Lt(re(x), 1)), cond)
assert reduce_poly_inequalities([[Ge(x**2, 1)]], x, relational=True) == And(Or(Le(re(x), -1), Le(1, re(x))), cond)
assert reduce_poly_inequalities([[Gt(x**2, 1)]], x, relational=True) == And(Or(Lt(re(x), -1), Lt(1, re(x))), cond)
assert reduce_poly_inequalities([[Ne(x**2, 1)]], x, relational=True) == And(Or(Lt(re(x), -1), And(Lt(-1, re(x)), Lt(re(x), 1)), Lt(1, re(x))), cond)
assert reduce_poly_inequalities([[Eq(x**2, 1.0)]], x, relational=True).evalf() == And(Or(Eq(re(x), -1.0), Eq(re(x), 1.0)), cond)
assert reduce_poly_inequalities([[Le(x**2, 1.0)]], x, relational=True) == And(And(Le(-1.0, re(x)), Le(re(x), 1.0)), cond)
assert reduce_poly_inequalities([[Lt(x**2, 1.0)]], x, relational=True) == And(And(Lt(-1.0, re(x)), Lt(re(x), 1.0)), cond)
assert reduce_poly_inequalities([[Ge(x**2, 1.0)]], x, relational=True) == And(Or(Le(re(x), -1.0), Le(1.0, re(x))), cond)
assert reduce_poly_inequalities([[Gt(x**2, 1.0)]], x, relational=True) == And(Or(Lt(re(x), -1.0), Lt(1.0, re(x))), cond)
assert reduce_poly_inequalities([[Ne(x**2, 1.0)]], x, relational=True) == And(Or(Lt(re(x), -1.0), And(Lt(-1.0, re(x)), Lt(re(x), 1.0)), Lt(1.0, re(x))), cond)
def test_reduce_poly_inequalities_real_interval():
with assuming(Q.real(x), Q.real(y)):
assert reduce_rational_inequalities(
[[Eq(x**2, 0)]], x, relational=False) == FiniteSet(0)
assert reduce_rational_inequalities(
[[Le(x**2, 0)]], x, relational=False) == FiniteSet(0)
assert reduce_rational_inequalities(
[[Lt(x**2, 0)]], x, relational=False) == S.EmptySet
assert reduce_rational_inequalities(
[[Ge(x**2, 0)]], x, relational=False) == Interval(-oo, oo)
assert reduce_rational_inequalities(
[[Gt(x**2, 0)]], x, relational=False) == FiniteSet(0).complement
assert reduce_rational_inequalities(
[[Ne(x**2, 0)]], x, relational=False) == FiniteSet(0).complement
assert reduce_rational_inequalities(
[[Eq(x**2, 1)]], x, relational=False) == FiniteSet(-1, 1)
assert reduce_rational_inequalities(
[[Le(x**2, 1)]], x, relational=False) == Interval(-1, 1)
assert reduce_rational_inequalities(
[[Lt(x**2, 1)]], x, relational=False) == Interval(-1, 1, True, True)
assert reduce_rational_inequalities([[Ge(x**2, 1)]], x, relational=False) == Union(Interval(-oo, -1), Interval(1, oo))
assert reduce_rational_inequalities(
[[Gt(x**2, 1)]], x, relational=False) == Interval(-1, 1).complement
assert reduce_rational_inequalities(
[[Ne(x**2, 1)]], x, relational=False) == FiniteSet(-1, 1).complement
assert reduce_rational_inequalities([[Eq(
x**2, 1.0)]], x, relational=False) == FiniteSet(-1.0, 1.0).evalf()
assert reduce_rational_inequalities(
[[Le(x**2, 1.0)]], x, relational=False) == Interval(-1.0, 1.0)
assert reduce_rational_inequalities([[Lt(
x**2, 1.0)]], x, relational=False) == Interval(-1.0, 1.0, True, True)
assert reduce_rational_inequalities([[Ge(x**2, 1.0)]], x, relational=False) == Union(Interval(-inf, -1.0), Interval(1.0, inf))
assert reduce_rational_inequalities([[Gt(x**2, 1.0)]], x, relational=False) == Union(Interval(-inf, -1.0, right_open=True), Interval(1.0, inf, left_open=True))
assert reduce_rational_inequalities([[Ne(
x**2, 1.0)]], x, relational=False) == FiniteSet(-1.0, 1.0).complement
s = sqrt(2)
assert reduce_rational_inequalities([[Lt(
x**2 - 1, 0), Gt(x**2 - 1, 0)]], x, relational=False) == S.EmptySet
assert reduce_rational_inequalities([[Le(x**2 - 1, 0), Ge(
x**2 - 1, 0)]], x, relational=False) == FiniteSet(-1, 1)
assert reduce_rational_inequalities([[Le(x**2 - 2, 0), Ge(x**2 - 1, 0)]], x, relational=False) == Union(Interval(-s, -1, False, False), Interval(1, s, False, False))
assert reduce_rational_inequalities([[Le(x**2 - 2, 0), Gt(x**2 - 1, 0)]], x, relational=False) == Union(Interval(-s, -1, False, True), Interval(1, s, True, False))
assert reduce_rational_inequalities([[Lt(x**2 - 2, 0), Ge(x**2 - 1, 0)]], x, relational=False) == Union(Interval(-s, -1, True, False), Interval(1, s, False, True))
assert reduce_rational_inequalities([[Lt(x**2 - 2, 0), Gt(x**2 - 1, 0)]], x, relational=False) == Union(Interval(-s, -1, True, True), Interval(1, s, True, True))
assert reduce_rational_inequalities([[Lt(x**2 - 2, 0), Ne(x**2 - 1, 0)]], x, relational=False) == Union(Interval(-s, -1, True, True), Interval(-1, 1, True, True), Interval(1, s, True, True))
def test_reduce_abs_inequalities():
x = Symbol('x', real=True)
assert reduce_inequalities(abs(x - 5) < 3) == And(Lt(2, x), Lt(x, 8))
assert reduce_inequalities(abs(2 * x + 3) >= 8) == Or(
And(Le(S(5) / 2, x), Lt(x, oo)), And(Le(x, -S(11) / 2), Lt(-oo, x)))
assert reduce_inequalities(abs(x - 4) + abs(3 * x - 5) < 7) == And(
Lt(S(1) / 2, x), Lt(x, 4))
assert reduce_inequalities(abs(x - 4) + abs(3*abs(x) - 5) < 7) == \
Or(And(S(-2) < x, x < -1), And(S(1)/2 < x, x < 4))
x = Symbol('x')
raises(NotImplementedError, lambda: reduce_inequalities(abs(x - 5) < 3))
def test_reduce_abs_inequalities():
e = abs(x - 5) < 3
ans = And(Lt(2, x), Lt(x, 8))
assert reduce_inequalities(e) == ans
assert reduce_inequalities(e, x) == ans
assert reduce_inequalities(abs(x - 5)) == Eq(x, 5)
assert reduce_inequalities(abs(2 * x + 3) >= 8) == Or(
And(Le(S(5) / 2, x), Lt(x, oo)), And(Le(x, -S(11) / 2), Lt(-oo, x)))
assert reduce_inequalities(abs(x - 4) + abs(3 * x - 5) < 7) == And(
Lt(S(1) / 2, x), Lt(x, 4))
assert reduce_inequalities(abs(x - 4) + abs(3*abs(x) - 5) < 7) == \
Or(And(S(-2) < x, x < -1), And(S(1)/2 < x, x < 4))
nr = Symbol('nr', real=False)
raises(TypeError, lambda: reduce_inequalities(abs(nr - 5) < 3))
def test_reduce_abs_inequalities():
e = abs(x - 5) < 3
ans = And(Lt(2, x), Lt(x, 8))
assert reduce_inequalities(e) == ans
assert reduce_inequalities(e, x) == ans
assert reduce_inequalities(abs(x - 5)) == Eq(x, 5)
assert reduce_inequalities(abs(2 * x + 3) >= 8) == Or(
And(Le(Rational(5, 2), x), Lt(x, oo)),
And(Le(x, Rational(-11, 2)), Lt(-oo, x)))
assert reduce_inequalities(abs(x - 4) + abs(3 * x - 5) < 7) == And(
Lt(S.Half, x), Lt(x, 4))
assert reduce_inequalities(abs(x - 4) + abs(3*abs(x) - 5) < 7) == \
Or(And(S(-2) < x, x < -1), And(S.Half < x, x < 4))
nr = Symbol('nr', extended_real=False)
raises(TypeError, lambda: reduce_inequalities(abs(nr - 5) < 3))
assert reduce_inequalities(x < 3, symbols=[x, nr]) == And(-oo < x, x < 3)
def newton_raphson_algorithm(expr,
wrt,
atol=1e-12,
delta=None,
debug=False,
itermax=None,
counter=None):
"""
See https://en.wikipedia.org/wiki/Newton%27s_method
"""
if delta is None:
delta = Dummy()
Wrapper = Scope
name_d = 'delta'
else:
Wrapper = lambda x: x
name_d = delta.name
delta_expr = -expr / expr.diff(wrt)
body = [Assignment(delta, delta_expr), AddAugmentedAssignment(wrt, delta)]
if debug:
prnt = PrintStatement(
r"{0}=%12.5g {1}=%12.5g\n".format(wrt.name, name_d),
Tuple(wrt, delta))
body = [body[0], prnt] + body[1:]
if isinstance(atol, float) and atol < 0:
atol = -atol * 10**-PrinterSetting('precision')
req = Gt(Abs(delta), atol)
declars = [Declaration(delta, oo)]
if itermax is not None:
counter = counter or Dummy(integer=True)
declars.append(Declaration(counter, 0))
body.append(AddAugmentedAssignment(counter, 1))
req = And(req, Lt(counter, itermax))
whl = While(req, CodeBlock(*body))
blck = declars + [whl]
return Wrapper(CodeBlock(*blck))
def test_presentation_mathml_relational():
mml_1 = mpp._print(Eq(x, 1))
assert len(mml_1.childNodes) == 3
assert mml_1.childNodes[0].nodeName == 'mi'
assert mml_1.childNodes[0].childNodes[0].nodeValue == 'x'
assert mml_1.childNodes[1].nodeName == 'mo'
assert mml_1.childNodes[1].childNodes[0].nodeValue == '='
assert mml_1.childNodes[2].nodeName == 'mn'
assert mml_1.childNodes[2].childNodes[0].nodeValue == '1'
mml_2 = mpp._print(Ne(1, x))
assert len(mml_2.childNodes) == 3
assert mml_2.childNodes[0].nodeName == 'mn'
assert mml_2.childNodes[0].childNodes[0].nodeValue == '1'
assert mml_2.childNodes[1].nodeName == 'mo'
assert mml_2.childNodes[1].childNodes[0].nodeValue == '≠'
assert mml_2.childNodes[2].nodeName == 'mi'
assert mml_2.childNodes[2].childNodes[0].nodeValue == 'x'
mml_3 = mpp._print(Ge(1, x))
assert len(mml_3.childNodes) == 3
assert mml_3.childNodes[0].nodeName == 'mn'
assert mml_3.childNodes[0].childNodes[0].nodeValue == '1'
assert mml_3.childNodes[1].nodeName == 'mo'
assert mml_3.childNodes[1].childNodes[0].nodeValue == '≥'
assert mml_3.childNodes[2].nodeName == 'mi'
assert mml_3.childNodes[2].childNodes[0].nodeValue == 'x'
mml_4 = mpp._print(Lt(1, x))
assert len(mml_4.childNodes) == 3
assert mml_4.childNodes[0].nodeName == 'mn'
assert mml_4.childNodes[0].childNodes[0].nodeValue == '1'
assert mml_4.childNodes[1].nodeName == 'mo'
assert mml_4.childNodes[1].childNodes[0].nodeValue == '<'
assert mml_4.childNodes[2].nodeName == 'mi'
assert mml_4.childNodes[2].childNodes[0].nodeValue == 'x'
def test_reduce_poly_inequalities_real_interval():
global_assumptions.add(x_assume)
global_assumptions.add(y_assume)
assert reduce_poly_inequalities([[Eq(x**2, 0)]], x, relational=False) == [Interval(0, 0)]
assert reduce_poly_inequalities([[Le(x**2, 0)]], x, relational=False) == [Interval(0, 0)]
assert reduce_poly_inequalities([[Lt(x**2, 0)]], x, relational=False) == []
assert reduce_poly_inequalities([[Ge(x**2, 0)]], x, relational=False) == [Interval(-oo, oo)]
assert reduce_poly_inequalities([[Gt(x**2, 0)]], x, relational=False) == [Interval(-oo, 0, right_open=True), Interval(0, oo, left_open=True)]
assert reduce_poly_inequalities([[Ne(x**2, 0)]], x, relational=False) == [Interval(-oo, 0, right_open=True), Interval(0, oo, left_open=True)]
assert reduce_poly_inequalities([[Eq(x**2, 1)]], x, relational=False) == [Interval(-1,-1), Interval(1, 1)]
assert reduce_poly_inequalities([[Le(x**2, 1)]], x, relational=False) == [Interval(-1, 1)]
assert reduce_poly_inequalities([[Lt(x**2, 1)]], x, relational=False) == [Interval(-1, 1, True, True)]
assert reduce_poly_inequalities([[Ge(x**2, 1)]], x, relational=False) == [Interval(-oo, -1), Interval(1, oo)]
assert reduce_poly_inequalities([[Gt(x**2, 1)]], x, relational=False) == [Interval(-oo, -1, right_open=True), Interval(1, oo, left_open=True)]
assert reduce_poly_inequalities([[Ne(x**2, 1)]], x, relational=False) == [Interval(-oo, -1, right_open=True), Interval(-1, 1, True, True), Interval(1, oo, left_open=True)]
assert reduce_poly_inequalities([[Eq(x**2, 1.0)]], x, relational=False) == [Interval(-1.0,-1.0), Interval(1.0, 1.0)]
assert reduce_poly_inequalities([[Le(x**2, 1.0)]], x, relational=False) == [Interval(-1.0, 1.0)]
assert reduce_poly_inequalities([[Lt(x**2, 1.0)]], x, relational=False) == [Interval(-1.0, 1.0, True, True)]
assert reduce_poly_inequalities([[Ge(x**2, 1.0)]], x, relational=False) == [Interval(-inf, -1.0), Interval(1.0, inf)]
assert reduce_poly_inequalities([[Gt(x**2, 1.0)]], x, relational=False) == [Interval(-inf, -1.0, right_open=True), Interval(1.0, inf, left_open=True)]
assert reduce_poly_inequalities([[Ne(x**2, 1.0)]], x, relational=False) == [Interval(-inf, -1.0, right_open=True), Interval(-1.0, 1.0, True, True), Interval(1.0, inf, left_open=True)]
s = sqrt(2)
assert reduce_poly_inequalities([[Lt(x**2 - 1, 0), Gt(x**2 - 1, 0)]], x, relational=False) == []
assert reduce_poly_inequalities([[Le(x**2 - 1, 0), Ge(x**2 - 1, 0)]], x, relational=False) == [Interval(-1,-1), Interval(1, 1)]
assert reduce_poly_inequalities([[Le(x**2 - 2, 0), Ge(x**2 - 1, 0)]], x, relational=False) == [Interval(-s, -1, False, False), Interval(1, s, False, False)]
assert reduce_poly_inequalities([[Le(x**2 - 2, 0), Gt(x**2 - 1, 0)]], x, relational=False) == [Interval(-s, -1, False, True), Interval(1, s, True, False)]
assert reduce_poly_inequalities([[Lt(x**2 - 2, 0), Ge(x**2 - 1, 0)]], x, relational=False) == [Interval(-s, -1, True, False), Interval(1, s, False, True)]
assert reduce_poly_inequalities([[Lt(x**2 - 2, 0), Gt(x**2 - 1, 0)]], x, relational=False) == [Interval(-s, -1, True, True), Interval(1, s, True, True)]
assert reduce_poly_inequalities([[Lt(x**2 - 2, 0), Ne(x**2 - 1, 0)]], x, relational=False) == [Interval(-s, -1, True, True), Interval(-1, 1, True, True), Interval(1, s, True, True)]
global_assumptions.remove(x_assume)
global_assumptions.remove(y_assume)
def test_Union_as_relational():
x = Symbol('x')
assert (Interval(0, 1) + FiniteSet(2)).as_relational(x) == \
Or(And(Le(0, x), Le(x, 1)), Eq(x, 2))
assert (Interval(0, 1, True, True) + FiniteSet(1)).as_relational(x) == \
And(Lt(0, x), Le(x, 1))
def test_Interval_as_relational():
x = Symbol('x')
assert Interval(-1, 2, False, False).as_relational(x) == \
And(Le(-1, x), Le(x, 2))
assert Interval(-1, 2, True, False).as_relational(x) == \
And(Lt(-1, x), Le(x, 2))
assert Interval(-1, 2, False, True).as_relational(x) == \
And(Le(-1, x), Lt(x, 2))
assert Interval(-1, 2, True, True).as_relational(x) == \
And(Lt(-1, x), Lt(x, 2))
assert Interval(-oo, 2, right_open=False).as_relational(x) == And(Lt(-oo, x), Le(x, 2))
assert Interval(-oo, 2, right_open=True).as_relational(x) == And(Lt(-oo, x), Lt(x, 2))
assert Interval(-2, oo, left_open=False).as_relational(x) == And(Le(-2, x), Lt(x, oo))
assert Interval(-2, oo, left_open=True).as_relational(x) == And(Lt(-2, x), Lt(x, oo))
assert Interval(-oo, oo).as_relational(x) == And(Lt(-oo, x), Lt(x, oo))
x = Symbol('x', real=True)
y = Symbol('y', real=True)
assert Interval(x, y).as_relational(x) == (x <= y)
assert Interval(y, x).as_relational(x) == (y <= x)
def high(self):
return Piecewise((self.n, Lt(self.n, self.m) != False), (self.m, True))
