Exemple #1
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def test_doit():
    from sympy import Symbol
    p = Symbol('p', positive=True)
    n = Symbol('n', negative=True)
    np = Symbol('np', nonpositive=True)
    nn = Symbol('nn', nonnegative=True)

    assert Gt(p, 0).doit() is S.true
    assert Gt(p, 1).doit() == Gt(p, 1)
    assert Ge(p, 0).doit() is S.true
    assert Le(p, 0).doit() is S.false
    assert Lt(n, 0).doit() is S.true
    assert Le(np, 0).doit() is S.true
    assert Gt(nn, 0).doit() == Gt(nn, 0)
    assert Lt(nn, 0).doit() is S.false

    assert Eq(x, 0).doit() == Eq(x, 0)
Exemple #2
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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)
Exemple #3
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 def pmf(self, x):
     x = sympify(x)
     if not (x.is_number or x.is_Symbol or is_random(x)):
         raise ValueError(
             "'x' expected as an argument of type 'number', 'Symbol', or "
             "'RandomSymbol' not %s" % (type(x)))
     cond = Ge(x, 1) & Le(x, self.sides) & Contains(x, S.Integers)
     return Piecewise((S.One / self.sides, cond), (S.Zero, True))
Exemple #4
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 def pmf(self, x):
     x = sympify(x)
     if not (x.is_number or x.is_Symbol or is_random(x)):
         raise ValueError("'x' expected as an argument of type 'number', 'Symbol', or "
                     "'RandomSymbol' not %s" % (type(x)))
     cond1 = Eq(x, 1) & x.is_integer
     cond2 = Ge(x, 1) & Le(x, self.k) & x.is_integer
     return Piecewise((1/self.k, cond1), (1/(x*(x - 1)), cond2), (S.Zero, True))
Exemple #5
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 def pmf(self, x):
     n, p = self.n, self.p
     x = sympify(x)
     if not (x.is_number or x.is_Symbol or is_random(x)):
         raise ValueError("'x' expected as an argument of type 'number', 'Symbol', or "
                     "'RandomSymbol' not %s" % (type(x)))
     cond = Ge(x, 0) & Le(x, n) & Contains(x, S.Integers)
     return Piecewise((binomial(n, x) * p**x * (1 - p)**(n - x), cond), (S.Zero, True))
Exemple #6
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def test_as_poly():
    from sympy.polys.polytools import Poly
    # Only Eq should have an as_poly method:
    assert Eq(x, 1).as_poly() == Poly(x - 1, x, domain='ZZ')
    raises(AttributeError, lambda: Ne(x, 1).as_poly())
    raises(AttributeError, lambda: Ge(x, 1).as_poly())
    raises(AttributeError, lambda: Gt(x, 1).as_poly())
    raises(AttributeError, lambda: Le(x, 1).as_poly())
    raises(AttributeError, lambda: Lt(x, 1).as_poly())
Exemple #7
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def test_evaluate():
    assert str(Eq(x, x, evaluate=False)) == "Eq(x, x)"
    assert Eq(x, x, evaluate=False).doit() == S.true
    assert str(Ne(x, x, evaluate=False)) == "Ne(x, x)"
    assert Ne(x, x, evaluate=False).doit() == S.false

    assert str(Ge(x, x, evaluate=False)) == "x >= x"
    assert str(Le(x, x, evaluate=False)) == "x <= x"
    assert str(Gt(x, x, evaluate=False)) == "x > x"
    assert str(Lt(x, x, evaluate=False)) == "x < x"
Exemple #8
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def test_evaluate():
    assert str(Eq(x, x, evaluate=False)) == 'Eq(x, x)'
    assert Eq(x, x, evaluate=False).doit() == S.true
    assert str(Ne(x, x, evaluate=False)) == 'Ne(x, x)'
    assert Ne(x, x, evaluate=False).doit() == S.false

    assert str(Ge(x, x, evaluate=False)) == 'x >= x'
    assert str(Le(x, x, evaluate=False)) == 'x <= x'
    assert str(Gt(x, x, evaluate=False)) == 'x > x'
    assert str(Lt(x, x, evaluate=False)) == 'x < x'
Exemple #9
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def test_python_relational():
    assert python(Eq(x, y)) == "x = Symbol('x')\ny = Symbol('y')\ne = Eq(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 = Ne(x/(1 + y), y**2)",
        "x = Symbol('x')\ny = Symbol('y')\ne = Ne(x/(y + 1), y**2)"
    ]
Exemple #10
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    def pmf(self, x):
        x = sympify(x)
        if not (x.is_number or x.is_Symbol or is_random(x)):
            raise ValueError(
                "'x' expected as an argument of type 'number', 'Symbol', or "
                "'RandomSymbol' not %s" % (type(x)))

        cond1 = Eq(x, 1) & x.is_integer
        cond2 = Ge(x, 1) & Le(x, self.k) & x.is_integer
        rho = Piecewise((Rational(1, self.k), cond1),
                        (Rational(1, x * (x - 1)), cond2), (S.Zero, True))

        cond1 = Ge(x, 1) & Le(x, round(self.k / self.R) - 1)
        cond2 = Eq(x, round(self.k / self.R))
        tau = Piecewise((self.R / (self.k * x), cond1),
                        (self.R * log(self.R / self.delta) / self.k, cond2),
                        (S.Zero, True))

        return (rho + tau) / self.Z
Exemple #11
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 def __le__(self, other):
     if self.is_extended_real:
         other = _sympify(other)
         # Check if other < 0
         if other.is_extended_negative:
             return S.false
         # Check if other >= 1
         res = self._value_one_or_more(other)
         if res is not None:
             return res
     return Le(self, other, evaluate=False)
Exemple #12
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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)
Exemple #13
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    def __le__(self, other):
        other = S(other)
        if self.args[0].is_real:
            if other.is_integer:
                return self.args[0] <= other
            if other.is_number and other.is_real:
                return self.args[0] <= floor(other)
        if self.args[0] == other and other.is_real:
            return S.false
        if other is S.Infinity and self.is_finite:
            return S.true

        return Le(self, other, evaluate=False)
Exemple #14
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def test_inequalities_symbol_name_same():
    """Using the operator and functional forms should give same results."""
    # We test all combinations from a set
    # FIXME: could replace with random selection after test passes
    A = (x, y, S.Zero, S.One / 3, pi, oo, -oo)
    for a in A:
        for b in A:
            assert Gt(a, b) == (a > b)
            assert Lt(a, b) == (a < b)
            assert Ge(a, b) == (a >= b)
            assert Le(a, b) == (a <= b)

    for b in (y, S.Zero, S.One / 3, pi, oo, -oo):
        assert Gt(x, b, evaluate=False) == (x > b)
        assert Lt(x, b, evaluate=False) == (x < b)
        assert Ge(x, b, evaluate=False) == (x >= b)
        assert Le(x, b, evaluate=False) == (x <= b)

    for b in (y, S.Zero, S.One / 3, pi, oo, -oo):
        assert Gt(b, x, evaluate=False) == (b > x)
        assert Lt(b, x, evaluate=False) == (b < x)
        assert Ge(b, x, evaluate=False) == (b >= x)
        assert Le(b, x, evaluate=False) == (b <= x)
Exemple #15
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def test_inequalities_symbol_name_same_complex():
    """Using the operator and functional forms should give same results.
    With complex non-real numbers, both should raise errors.
    """
    # FIXME: could replace with random selection after test passes
    for a in (x, S.Zero, S.One / 3, pi, oo, Rational(1, 3)):
        raises(TypeError, lambda: Gt(a, I))
        raises(TypeError, lambda: a > I)
        raises(TypeError, lambda: Lt(a, I))
        raises(TypeError, lambda: a < I)
        raises(TypeError, lambda: Ge(a, I))
        raises(TypeError, lambda: a >= I)
        raises(TypeError, lambda: Le(a, I))
        raises(TypeError, lambda: a <= I)
Exemple #16
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    def as_relational(self, symbol):
        """Rewrite an interval in terms of inequalities and logic operators. """
        from sympy.core.relational import Lt, Le

        if not self.is_left_unbounded:
            if self.left_open:
                left = Lt(self.start, symbol)
            else:
                left = Le(self.start, symbol)

        if not self.is_right_unbounded:
            if self.right_open:
                right = Lt(symbol, self.right)
            else:
                right = Le(symbol, self.right)
        if self.is_left_unbounded and self.is_right_unbounded:
            return True  # XXX: Contained(symbol, Floats)
        elif self.is_left_unbounded:
            return right
        elif self.is_right_unbounded:
            return left
        else:
            return And(left, right)
Exemple #17
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def test_inequalities_symbol_name_same():
    """Using the operator and functional forms should give same results."""
    # currently fails because rhs reduces to bool but the lhs does not
    assert Lt(x, oo) == (x < oo)

    # We test all combinations from a set
    # FIXME: could replace with random selection after test passes
    A = (x, y, S(0), S(1) / 3, pi, oo, -oo)
    for a in A:
        for b in A:
            assert Gt(a, b) == (a > b)
            assert Lt(a, b) == (a < b)
            assert Ge(a, b) == (a >= b)
            assert Le(a, b) == (a <= b)
Exemple #18
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def test_bool():
    assert Eq(0, 0) is True
    assert Eq(1, 0) is False
    assert Ne(0, 0) is False
    assert Ne(1, 0) is True
    assert Lt(0, 1) is True
    assert Lt(1, 0) is False
    assert Le(0, 1) is True
    assert Le(1, 0) is False
    assert Le(0, 0) is True
    assert Gt(1, 0) is True
    assert Gt(0, 1) is False
    assert Ge(1, 0) is True
    assert Ge(0, 1) is False
    assert Ge(1, 1) is True
    assert Eq(I, 2) is False
    assert Ne(I, 2) is True
    assert Gt(I, 2) not in [True, False]
    assert Ge(I, 2) not in [True, False]
    assert Lt(I, 2) not in [True, False]
    assert Le(I, 2) not in [True, False]
    a = Float('.000000000000000000001', '')
    b = Float('.0000000000000000000001', '')
    assert Eq(pi + a, pi + b) is False
Exemple #19
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def test_bool():
    assert Eq(0, 0) is S.true
    assert Eq(1, 0) is S.false
    assert Ne(0, 0) is S.false
    assert Ne(1, 0) is S.true
    assert Lt(0, 1) is S.true
    assert Lt(1, 0) is S.false
    assert Le(0, 1) is S.true
    assert Le(1, 0) is S.false
    assert Le(0, 0) is S.true
    assert Gt(1, 0) is S.true
    assert Gt(0, 1) is S.false
    assert Ge(1, 0) is S.true
    assert Ge(0, 1) is S.false
    assert Ge(1, 1) is S.true
    assert Eq(I, 2) is S.false
    assert Ne(I, 2) is S.true
    raises(TypeError, lambda: Gt(I, 2))
    raises(TypeError, lambda: Ge(I, 2))
    raises(TypeError, lambda: Lt(I, 2))
    raises(TypeError, lambda: Le(I, 2))
    a = Float('.000000000000000000001', '')
    b = Float('.0000000000000000000001', '')
    assert Eq(pi + a, pi + b) is S.false
Exemple #20
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def test_wrappers():
    e = x + x**2

    res = Relational(y, e, '==')
    assert Rel(y, x + x**2, '==') == res
    assert Eq(y, x + x**2) == res

    res = Relational(y, e, '<')
    assert Lt(y, x + x**2) == res

    res = Relational(y, e, '<=')
    assert Le(y, x + x**2) == res

    res = Relational(y, e, '>')
    assert Gt(y, x + x**2) == res

    res = Relational(y, e, '>=')
    assert Ge(y, x + x**2) == res

    res = Relational(y, e, '!=')
    assert Ne(y, x + x**2) == res
Exemple #21
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def test_reversedsign_property():
    eq = Eq(x, y)
    assert eq.reversedsign == Eq(-x, -y)

    eq = Ne(x, y)
    assert eq.reversedsign == Ne(-x, -y)

    eq = Ge(x + y, y - x)
    assert eq.reversedsign == Le(-x - y, x - y)

    for f in (Eq, Ne, Ge, Gt, Le, Lt):
        assert f(x, y).reversedsign.reversedsign == f(x, y)

    for f in (Eq, Ne, Ge, Gt, Le, Lt):
        assert f(-x, y).reversedsign.reversedsign == f(-x, y)

    for f in (Eq, Ne, Ge, Gt, Le, Lt):
        assert f(x, -y).reversedsign.reversedsign == f(x, -y)

    for f in (Eq, Ne, Ge, Gt, Le, Lt):
        assert f(-x, -y).reversedsign.reversedsign == f(-x, -y)
Exemple #22
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def test_wrappers():
    e = x + x ** 2

    res = Relational(y, e, "==")
    assert Rel(y, x + x ** 2, "==") == res
    assert Eq(y, x + x ** 2) == res

    res = Relational(y, e, "<")
    assert Lt(y, x + x ** 2) == res

    res = Relational(y, e, "<=")
    assert Le(y, x + x ** 2) == res

    res = Relational(y, e, ">")
    assert Gt(y, x + x ** 2) == res

    res = Relational(y, e, ">=")
    assert Ge(y, x + x ** 2) == res

    res = Relational(y, e, "!=")
    assert Ne(y, x + x ** 2) == res
def test_reduce_poly_inequalities_complex_relational():
    assert reduce_rational_inequalities([[Eq(x**2, 0)]], x,
                                        relational=True) == Eq(x, 0)
    assert reduce_rational_inequalities([[Le(x**2, 0)]], x,
                                        relational=True) == Eq(x, 0)
    assert reduce_rational_inequalities([[Lt(x**2, 0)]], x,
                                        relational=True) == False
    assert reduce_rational_inequalities([[Ge(x**2, 0)]], x,
                                        relational=True) == And(
                                            Lt(-oo, x), Lt(x, oo))
    assert reduce_rational_inequalities(
        [[Gt(x**2, 0)]], x, relational=True) == \
        And(Gt(x, -oo), Lt(x, oo), Ne(x, 0))
    assert reduce_rational_inequalities(
        [[Ne(x**2, 0)]], x, relational=True) == \
        And(Gt(x, -oo), Lt(x, oo), Ne(x, 0))

    for one in (S.One, S(1.0)):
        inf = one * oo
        assert reduce_rational_inequalities(
            [[Eq(x**2, one)]], x, relational=True) == \
            Or(Eq(x, -one), Eq(x, one))
        assert reduce_rational_inequalities(
            [[Le(x**2, one)]], x, relational=True) == \
            And(And(Le(-one, x), Le(x, one)))
        assert reduce_rational_inequalities(
            [[Lt(x**2, one)]], x, relational=True) == \
            And(And(Lt(-one, x), Lt(x, one)))
        assert reduce_rational_inequalities(
            [[Ge(x**2, one)]], x, relational=True) == \
            And(Or(And(Le(one, x), Lt(x, inf)), And(Le(x, -one), Lt(-inf, x))))
        assert reduce_rational_inequalities(
            [[Gt(x**2, one)]], x, relational=True) == \
            And(Or(And(Lt(-inf, x), Lt(x, -one)), And(Lt(one, x), Lt(x, inf))))
        assert reduce_rational_inequalities(
            [[Ne(x**2, one)]], x, relational=True) == \
            Or(And(Lt(-inf, x), Lt(x, -one)),
               And(Lt(-one, x), Lt(x, one)),
               And(Lt(one, x), Lt(x, inf)))
Exemple #24
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def test_issue_8449():
    p = Symbol('p', nonnegative=True)
    assert Lt(-oo, p)
    assert Ge(-oo, p) is S.false
    assert Gt(oo, -p)
    assert Le(oo, -p) is S.false
Exemple #25
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def test_simplify_relational():
    assert simplify(x * (y + 1) - x * y - x + 1 < x) == (x > 1)
    assert simplify(x * (y + 1) - x * y - x - 1 < x) == (x > -1)
    assert simplify(x < x * (y + 1) - x * y - x + 1) == (x < 1)
    q, r = symbols("q r")
    assert (((-q + r) - (q - r)) <= 0).simplify() == (q >= r)
    root2 = sqrt(2)
    equation = ((root2 * (-q + r) - root2 * (q - r)) <= 0).simplify()
    assert equation == (q >= r)
    r = S.One < x
    # canonical operations are not the same as simplification,
    # so if there is no simplification, canonicalization will
    # be done unless the measure forbids it
    assert simplify(r) == r.canonical
    assert simplify(r, ratio=0) != r.canonical
    # this is not a random test; in _eval_simplify
    # this will simplify to S.false and that is the
    # reason for the 'if r.is_Relational' in Relational's
    # _eval_simplify routine
    assert simplify(-(2**(pi * Rational(3, 2)) + 6**pi)**(1 / pi) + 2 *
                    (2**(pi / 2) + 3**pi)**(1 / pi) < 0) is S.false
    # canonical at least
    assert Eq(y, x).simplify() == Eq(x, y)
    assert Eq(x - 1, 0).simplify() == Eq(x, 1)
    assert Eq(x - 1, x).simplify() == S.false
    assert Eq(2 * x - 1, x).simplify() == Eq(x, 1)
    assert Eq(2 * x, 4).simplify() == Eq(x, 2)
    z = cos(1)**2 + sin(1)**2 - 1  # z.is_zero is None
    assert Eq(z * x, 0).simplify() == S.true

    assert Ne(y, x).simplify() == Ne(x, y)
    assert Ne(x - 1, 0).simplify() == Ne(x, 1)
    assert Ne(x - 1, x).simplify() == S.true
    assert Ne(2 * x - 1, x).simplify() == Ne(x, 1)
    assert Ne(2 * x, 4).simplify() == Ne(x, 2)
    assert Ne(z * x, 0).simplify() == S.false

    # No real-valued assumptions
    assert Ge(y, x).simplify() == Le(x, y)
    assert Ge(x - 1, 0).simplify() == Ge(x, 1)
    assert Ge(x - 1, x).simplify() == S.false
    assert Ge(2 * x - 1, x).simplify() == Ge(x, 1)
    assert Ge(2 * x, 4).simplify() == Ge(x, 2)
    assert Ge(z * x, 0).simplify() == S.true
    assert Ge(x, -2).simplify() == Ge(x, -2)
    assert Ge(-x, -2).simplify() == Le(x, 2)
    assert Ge(x, 2).simplify() == Ge(x, 2)
    assert Ge(-x, 2).simplify() == Le(x, -2)

    assert Le(y, x).simplify() == Ge(x, y)
    assert Le(x - 1, 0).simplify() == Le(x, 1)
    assert Le(x - 1, x).simplify() == S.true
    assert Le(2 * x - 1, x).simplify() == Le(x, 1)
    assert Le(2 * x, 4).simplify() == Le(x, 2)
    assert Le(z * x, 0).simplify() == S.true
    assert Le(x, -2).simplify() == Le(x, -2)
    assert Le(-x, -2).simplify() == Ge(x, 2)
    assert Le(x, 2).simplify() == Le(x, 2)
    assert Le(-x, 2).simplify() == Ge(x, -2)

    assert Gt(y, x).simplify() == Lt(x, y)
    assert Gt(x - 1, 0).simplify() == Gt(x, 1)
    assert Gt(x - 1, x).simplify() == S.false
    assert Gt(2 * x - 1, x).simplify() == Gt(x, 1)
    assert Gt(2 * x, 4).simplify() == Gt(x, 2)
    assert Gt(z * x, 0).simplify() == S.false
    assert Gt(x, -2).simplify() == Gt(x, -2)
    assert Gt(-x, -2).simplify() == Lt(x, 2)
    assert Gt(x, 2).simplify() == Gt(x, 2)
    assert Gt(-x, 2).simplify() == Lt(x, -2)

    assert Lt(y, x).simplify() == Gt(x, y)
    assert Lt(x - 1, 0).simplify() == Lt(x, 1)
    assert Lt(x - 1, x).simplify() == S.true
    assert Lt(2 * x - 1, x).simplify() == Lt(x, 1)
    assert Lt(2 * x, 4).simplify() == Lt(x, 2)
    assert Lt(z * x, 0).simplify() == S.false
    assert Lt(x, -2).simplify() == Lt(x, -2)
    assert Lt(-x, -2).simplify() == Gt(x, 2)
    assert Lt(x, 2).simplify() == Lt(x, 2)
    assert Lt(-x, 2).simplify() == Gt(x, -2)

    # Test particulat branches of _eval_simplify
    m = exp(1) - exp_polar(1)
    assert simplify(m * x > 1) is S.false
    # These two tests the same branch
    assert simplify(m * x + 2 * m * y > 1) is S.false
    assert simplify(m * x + y > 1 + y) is S.false
Exemple #26
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 def __le__(self, other):
     if self.args[0] == other and other.is_real:
         return S.true
     return Le(self, other, evaluate=False)
Exemple #27
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def test_DiscreteMarkovChain():

    # pass only the name
    X = DiscreteMarkovChain("X")
    assert isinstance(X.state_space, Range)
    assert X.index_set == S.Naturals0
    assert isinstance(X.transition_probabilities, MatrixSymbol)
    t = symbols('t', positive=True, integer=True)
    assert isinstance(X[t], RandomIndexedSymbol)
    assert E(X[0]) == Expectation(X[0])
    raises(TypeError, lambda: DiscreteMarkovChain(1))
    raises(NotImplementedError, lambda: X(t))
    raises(NotImplementedError, lambda: X.communication_classes())
    raises(NotImplementedError, lambda: X.canonical_form())
    raises(NotImplementedError, lambda: X.decompose())

    nz = Symbol('n', integer=True)
    TZ = MatrixSymbol('M', nz, nz)
    SZ = Range(nz)
    YZ = DiscreteMarkovChain('Y', SZ, TZ)
    assert P(Eq(YZ[2], 1), Eq(YZ[1], 0)) == TZ[0, 1]

    raises(ValueError, lambda: sample_stochastic_process(t))
    raises(ValueError, lambda: next(sample_stochastic_process(X)))
    # pass name and state_space
    # any hashable object should be a valid state
    # states should be valid as a tuple/set/list/Tuple/Range
    sym, rainy, cloudy, sunny = symbols('a Rainy Cloudy Sunny', real=True)
    state_spaces = [(1, 2, 3), [Str('Hello'), sym, DiscreteMarkovChain],
                    Tuple(S(1), exp(sym), Str('World'), sympify=False),
                    Range(-1, 5, 2), [rainy, cloudy, sunny]]
    chains = [
        DiscreteMarkovChain("Y", state_space) for state_space in state_spaces
    ]

    for i, Y in enumerate(chains):
        assert isinstance(Y.transition_probabilities, MatrixSymbol)
        assert Y.state_space == state_spaces[i] or Y.state_space == FiniteSet(
            *state_spaces[i])
        assert Y.number_of_states == 3

        with ignore_warnings(
                UserWarning):  # TODO: Restore tests once warnings are removed
            assert P(Eq(Y[2], 1), Eq(Y[0], 2),
                     evaluate=False) == Probability(Eq(Y[2], 1), Eq(Y[0], 2))
        assert E(Y[0]) == Expectation(Y[0])

        raises(ValueError, lambda: next(sample_stochastic_process(Y)))

    raises(TypeError, lambda: DiscreteMarkovChain("Y", dict((1, 1))))
    Y = DiscreteMarkovChain("Y", Range(1, t, 2))
    assert Y.number_of_states == ceiling((t - 1) / 2)

    # pass name and transition_probabilities
    chains = [
        DiscreteMarkovChain("Y", trans_probs=Matrix([[]])),
        DiscreteMarkovChain("Y", trans_probs=Matrix([[0, 1], [1, 0]])),
        DiscreteMarkovChain("Y",
                            trans_probs=Matrix([[pi, 1 - pi], [sym, 1 - sym]]))
    ]
    for Z in chains:
        assert Z.number_of_states == Z.transition_probabilities.shape[0]
        assert isinstance(Z.transition_probabilities, ImmutableMatrix)

    # pass name, state_space and transition_probabilities
    T = Matrix([[0.5, 0.2, 0.3], [0.2, 0.5, 0.3], [0.2, 0.3, 0.5]])
    TS = MatrixSymbol('T', 3, 3)
    Y = DiscreteMarkovChain("Y", [0, 1, 2], T)
    YS = DiscreteMarkovChain("Y", ['One', 'Two', 3], TS)
    assert Y.joint_distribution(1, Y[2],
                                3) == JointDistribution(Y[1], Y[2], Y[3])
    raises(ValueError, lambda: Y.joint_distribution(Y[1].symbol, Y[2].symbol))
    assert P(Eq(Y[3], 2), Eq(Y[1], 1)).round(2) == Float(0.36, 2)
    assert (P(Eq(YS[3], 2), Eq(YS[1], 1)) -
            (TS[0, 2] * TS[1, 0] + TS[1, 1] * TS[1, 2] +
             TS[1, 2] * TS[2, 2])).simplify() == 0
    assert P(Eq(YS[1], 1), Eq(YS[2], 2)) == Probability(Eq(YS[1], 1))
    assert P(Eq(YS[3], 3), Eq(
        YS[1],
        1)) == TS[0, 2] * TS[1, 0] + TS[1, 1] * TS[1, 2] + TS[1, 2] * TS[2, 2]
    TO = Matrix([[0.25, 0.75, 0], [0, 0.25, 0.75], [0.75, 0, 0.25]])
    assert P(Eq(Y[3], 2),
             Eq(Y[1], 1) & TransitionMatrixOf(Y, TO)).round(3) == Float(
                 0.375, 3)
    with ignore_warnings(
            UserWarning):  ### TODO: Restore tests once warnings are removed
        assert E(Y[3], evaluate=False) == Expectation(Y[3])
        assert E(Y[3], Eq(Y[2], 1)).round(2) == Float(1.1, 3)
    TSO = MatrixSymbol('T', 4, 4)
    raises(
        ValueError,
        lambda: str(P(Eq(YS[3], 2),
                      Eq(YS[1], 1) & TransitionMatrixOf(YS, TSO))))
    raises(TypeError,
           lambda: DiscreteMarkovChain("Z", [0, 1, 2], symbols('M')))
    raises(
        ValueError,
        lambda: DiscreteMarkovChain("Z", [0, 1, 2], MatrixSymbol('T', 3, 4)))
    raises(ValueError, lambda: E(Y[3], Eq(Y[2], 6)))
    raises(ValueError, lambda: E(Y[2], Eq(Y[3], 1)))

    # extended tests for probability queries
    TO1 = Matrix([[Rational(1, 4), Rational(3, 4), 0],
                  [Rational(1, 3),
                   Rational(1, 3),
                   Rational(1, 3)], [0, Rational(1, 4),
                                     Rational(3, 4)]])
    assert P(
        And(Eq(Y[2], 1), Eq(Y[1], 1), Eq(Y[0], 0)),
        Eq(Probability(Eq(Y[0], 0)), Rational(1, 4))
        & TransitionMatrixOf(Y, TO1)) == Rational(1, 16)
    assert P(And(Eq(Y[2], 1), Eq(Y[1], 1), Eq(Y[0], 0)), TransitionMatrixOf(Y, TO1)) == \
            Probability(Eq(Y[0], 0))/4
    assert P(
        Lt(X[1], 2) & Gt(X[1], 0),
        Eq(X[0], 2) & StochasticStateSpaceOf(X, [0, 1, 2])
        & TransitionMatrixOf(X, TO1)) == Rational(1, 4)
    assert P(
        Lt(X[1], 2) & Gt(X[1], 0),
        Eq(X[0], 2) & StochasticStateSpaceOf(X, [None, 'None', 1])
        & TransitionMatrixOf(X, TO1)) == Rational(1, 4)
    assert P(
        Ne(X[1], 2) & Ne(X[1], 1),
        Eq(X[0], 2) & StochasticStateSpaceOf(X, [0, 1, 2])
        & TransitionMatrixOf(X, TO1)) is S.Zero
    assert P(
        Ne(X[1], 2) & Ne(X[1], 1),
        Eq(X[0], 2) & StochasticStateSpaceOf(X, [None, 'None', 1])
        & TransitionMatrixOf(X, TO1)) is S.Zero
    assert P(And(Eq(Y[2], 1), Eq(Y[1], 1), Eq(Y[0], 0)),
             Eq(Y[1], 1)) == 0.1 * Probability(Eq(Y[0], 0))

    # testing properties of Markov chain
    TO2 = Matrix([[S.One, 0, 0],
                  [Rational(1, 3),
                   Rational(1, 3),
                   Rational(1, 3)], [0, Rational(1, 4),
                                     Rational(3, 4)]])
    TO3 = Matrix([[Rational(1, 4), Rational(3, 4), 0],
                  [Rational(1, 3),
                   Rational(1, 3),
                   Rational(1, 3)], [0, Rational(1, 4),
                                     Rational(3, 4)]])
    Y2 = DiscreteMarkovChain('Y', trans_probs=TO2)
    Y3 = DiscreteMarkovChain('Y', trans_probs=TO3)
    assert Y3.fundamental_matrix() == ImmutableMatrix(
        [[176, 81, -132], [36, 141, -52], [-44, -39, 208]]) / 125
    assert Y2.is_absorbing_chain() == True
    assert Y3.is_absorbing_chain() == False
    assert Y2.canonical_form() == ([0, 1, 2], TO2)
    assert Y3.canonical_form() == ([0, 1, 2], TO3)
    assert Y2.decompose() == ([0, 1,
                               2], TO2[0:1, 0:1], TO2[1:3, 0:1], TO2[1:3, 1:3])
    assert Y3.decompose() == ([0, 1, 2], TO3, Matrix(0, 3,
                                                     []), Matrix(0, 0, []))
    TO4 = Matrix([[Rational(1, 5),
                   Rational(2, 5),
                   Rational(2, 5)], [Rational(1, 10), S.Half,
                                     Rational(2, 5)],
                  [Rational(3, 5),
                   Rational(3, 10),
                   Rational(1, 10)]])
    Y4 = DiscreteMarkovChain('Y', trans_probs=TO4)
    w = ImmutableMatrix([[Rational(11, 39),
                          Rational(16, 39),
                          Rational(4, 13)]])
    assert Y4.limiting_distribution == w
    assert Y4.is_regular() == True
    assert Y4.is_ergodic() == True
    TS1 = MatrixSymbol('T', 3, 3)
    Y5 = DiscreteMarkovChain('Y', trans_probs=TS1)
    assert Y5.limiting_distribution(w, TO4).doit() == True
    assert Y5.stationary_distribution(condition_set=True).subs(
        TS1, TO4).contains(w).doit() == S.true
    TO6 = Matrix([[S.One, 0, 0, 0, 0], [S.Half, 0, S.Half, 0, 0],
                  [0, S.Half, 0, S.Half, 0], [0, 0, S.Half, 0, S.Half],
                  [0, 0, 0, 0, 1]])
    Y6 = DiscreteMarkovChain('Y', trans_probs=TO6)
    assert Y6.fundamental_matrix() == ImmutableMatrix(
        [[Rational(3, 2), S.One, S.Half], [S.One, S(2), S.One],
         [S.Half, S.One, Rational(3, 2)]])
    assert Y6.absorbing_probabilities() == ImmutableMatrix(
        [[Rational(3, 4), Rational(1, 4)], [S.Half, S.Half],
         [Rational(1, 4), Rational(3, 4)]])
    TO7 = Matrix([[Rational(1, 2),
                   Rational(1, 4),
                   Rational(1, 4)], [Rational(1, 2), 0,
                                     Rational(1, 2)],
                  [Rational(1, 4),
                   Rational(1, 4),
                   Rational(1, 2)]])
    Y7 = DiscreteMarkovChain('Y', trans_probs=TO7)
    assert Y7.is_absorbing_chain() == False
    assert Y7.fundamental_matrix() == ImmutableMatrix(
        [[Rational(86, 75),
          Rational(1, 25),
          Rational(-14, 75)],
         [Rational(2, 25), Rational(21, 25),
          Rational(2, 25)],
         [Rational(-14, 75),
          Rational(1, 25),
          Rational(86, 75)]])

    # test for zero-sized matrix functionality
    X = DiscreteMarkovChain('X', trans_probs=Matrix([[]]))
    assert X.number_of_states == 0
    assert X.stationary_distribution() == Matrix([[]])
    assert X.communication_classes() == []
    assert X.canonical_form() == ([], Matrix([[]]))
    assert X.decompose() == ([], Matrix([[]]), Matrix([[]]), Matrix([[]]))
    assert X.is_regular() == False
    assert X.is_ergodic() == False

    # test communication_class
    # see https://drive.google.com/drive/folders/1HbxLlwwn2b3U8Lj7eb_ASIUb5vYaNIjg?usp=sharing
    # tutorial 2.pdf
    TO7 = Matrix([[0, 5, 5, 0, 0], [0, 0, 0, 10, 0], [5, 0, 5, 0, 0],
                  [0, 10, 0, 0, 0], [0, 3, 0, 3, 4]]) / 10
    Y7 = DiscreteMarkovChain('Y', trans_probs=TO7)
    tuples = Y7.communication_classes()
    classes, recurrence, periods = list(zip(*tuples))
    assert classes == ([1, 3], [0, 2], [4])
    assert recurrence == (True, False, False)
    assert periods == (2, 1, 1)

    TO8 = Matrix([[0, 0, 0, 10, 0, 0], [5, 0, 5, 0, 0, 0], [0, 4, 0, 0, 0, 6],
                  [10, 0, 0, 0, 0, 0], [0, 10, 0, 0, 0, 0], [0, 0, 0, 5, 5, 0]
                  ]) / 10
    Y8 = DiscreteMarkovChain('Y', trans_probs=TO8)
    tuples = Y8.communication_classes()
    classes, recurrence, periods = list(zip(*tuples))
    assert classes == ([0, 3], [1, 2, 5, 4])
    assert recurrence == (True, False)
    assert periods == (2, 2)

    TO9 = Matrix(
        [[2, 0, 0, 3, 0, 0, 3, 2, 0, 0], [0, 10, 0, 0, 0, 0, 0, 0, 0, 0],
         [0, 2, 2, 0, 0, 0, 0, 0, 3, 3], [0, 0, 0, 3, 0, 0, 6, 1, 0, 0],
         [0, 0, 0, 0, 5, 5, 0, 0, 0, 0], [0, 0, 0, 0, 0, 10, 0, 0, 0, 0],
         [4, 0, 0, 5, 0, 0, 1, 0, 0, 0], [2, 0, 0, 4, 0, 0, 2, 2, 0, 0],
         [3, 0, 1, 0, 0, 0, 0, 0, 4, 2], [0, 0, 4, 0, 0, 0, 0, 0, 3, 3]]) / 10
    Y9 = DiscreteMarkovChain('Y', trans_probs=TO9)
    tuples = Y9.communication_classes()
    classes, recurrence, periods = list(zip(*tuples))
    assert classes == ([0, 3, 6, 7], [1], [2, 8, 9], [5], [4])
    assert recurrence == (True, True, False, True, False)
    assert periods == (1, 1, 1, 1, 1)

    # test canonical form
    # see https://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/Chapter11.pdf
    # example 11.13
    T = Matrix([[1, 0, 0, 0, 0], [S(1) / 2, 0, S(1) / 2, 0, 0],
                [0, S(1) / 2, 0, S(1) / 2, 0], [0, 0,
                                                S(1) / 2, 0,
                                                S(1) / 2], [0, 0, 0, 0,
                                                            S(1)]])
    DW = DiscreteMarkovChain('DW', [0, 1, 2, 3, 4], T)
    states, A, B, C = DW.decompose()
    assert states == [0, 4, 1, 2, 3]
    assert A == Matrix([[1, 0], [0, 1]])
    assert B == Matrix([[S(1) / 2, 0], [0, 0], [0, S(1) / 2]])
    assert C == Matrix([[0, S(1) / 2, 0], [S(1) / 2, 0, S(1) / 2],
                        [0, S(1) / 2, 0]])
    states, new_matrix = DW.canonical_form()
    assert states == [0, 4, 1, 2, 3]
    assert new_matrix == Matrix([[1, 0, 0, 0, 0], [0, 1, 0, 0, 0],
                                 [S(1) / 2, 0, 0, S(1) / 2, 0],
                                 [0, 0, S(1) / 2, 0,
                                  S(1) / 2], [0, S(1) / 2, 0,
                                              S(1) / 2, 0]])

    # test regular and ergodic
    # https://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/Chapter11.pdf
    T = Matrix([[0, 4, 0, 0, 0], [1, 0, 3, 0, 0], [0, 2, 0, 2, 0],
                [0, 0, 3, 0, 1], [0, 0, 0, 4, 0]]) / 4
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert not X.is_regular()
    assert X.is_ergodic()
    T = Matrix([[0, 1], [1, 0]])
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert not X.is_regular()
    assert X.is_ergodic()
    # http://www.math.wisc.edu/~valko/courses/331/MC2.pdf
    T = Matrix([[2, 1, 1], [2, 0, 2], [1, 1, 2]]) / 4
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert X.is_regular()
    assert X.is_ergodic()
    # https://docs.ufpr.br/~lucambio/CE222/1S2014/Kemeny-Snell1976.pdf
    T = Matrix([[1, 1], [1, 1]]) / 2
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert X.is_regular()
    assert X.is_ergodic()

    # test is_absorbing_chain
    T = Matrix([[0, 1, 0], [1, 0, 0], [0, 0, 1]])
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert not X.is_absorbing_chain()
    # https://en.wikipedia.org/wiki/Absorbing_Markov_chain
    T = Matrix([[1, 1, 0, 0], [0, 1, 1, 0], [1, 0, 0, 1], [0, 0, 0, 2]]) / 2
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert X.is_absorbing_chain()
    T = Matrix([[2, 0, 0, 0, 0], [1, 0, 1, 0, 0], [0, 1, 0, 1, 0],
                [0, 0, 1, 0, 1], [0, 0, 0, 0, 2]]) / 2
    X = DiscreteMarkovChain('X', trans_probs=T)
    assert X.is_absorbing_chain()

    # test custom state space
    Y10 = DiscreteMarkovChain('Y', [1, 2, 3], TO2)
    tuples = Y10.communication_classes()
    classes, recurrence, periods = list(zip(*tuples))
    assert classes == ([1], [2, 3])
    assert recurrence == (True, False)
    assert periods == (1, 1)
    assert Y10.canonical_form() == ([1, 2, 3], TO2)
    assert Y10.decompose() == ([1, 2, 3], TO2[0:1, 0:1], TO2[1:3,
                                                             0:1], TO2[1:3,
                                                                       1:3])

    # testing miscellaneous queries
    T = Matrix([[S.Half, Rational(1, 4),
                 Rational(1, 4)], [Rational(1, 3), 0,
                                   Rational(2, 3)], [S.Half, S.Half, 0]])
    X = DiscreteMarkovChain('X', [0, 1, 2], T)
    assert P(
        Eq(X[1], 2) & Eq(X[2], 1) & Eq(X[3], 0),
        Eq(P(Eq(X[1], 0)), Rational(1, 4))
        & Eq(P(Eq(X[1], 1)), Rational(1, 4))) == Rational(1, 12)
    assert P(Eq(X[2], 1) | Eq(X[2], 2), Eq(X[1], 1)) == Rational(2, 3)
    assert P(Eq(X[2], 1) & Eq(X[2], 2), Eq(X[1], 1)) is S.Zero
    assert P(Ne(X[2], 2), Eq(X[1], 1)) == Rational(1, 3)
    assert E(X[1]**2, Eq(X[0], 1)) == Rational(8, 3)
    assert variance(X[1], Eq(X[0], 1)) == Rational(8, 9)
    raises(ValueError, lambda: E(X[1], Eq(X[2], 1)))
    raises(ValueError, lambda: DiscreteMarkovChain('X', [0, 1], T))

    # testing miscellaneous queries with different state space
    X = DiscreteMarkovChain('X', ['A', 'B', 'C'], T)
    assert P(
        Eq(X[1], 2) & Eq(X[2], 1) & Eq(X[3], 0),
        Eq(P(Eq(X[1], 0)), Rational(1, 4))
        & Eq(P(Eq(X[1], 1)), Rational(1, 4))) == Rational(1, 12)
    assert P(Eq(X[2], 1) | Eq(X[2], 2), Eq(X[1], 1)) == Rational(2, 3)
    assert P(Eq(X[2], 1) & Eq(X[2], 2), Eq(X[1], 1)) is S.Zero
    assert P(Ne(X[2], 2), Eq(X[1], 1)) == Rational(1, 3)
    a = X.state_space.args[0]
    c = X.state_space.args[2]
    assert (E(X[1]**2, Eq(X[0], 1)) -
            (a**2 / 3 + 2 * c**2 / 3)).simplify() == 0
    assert (variance(X[1], Eq(X[0], 1)) -
            (2 * (-a / 3 + c / 3)**2 / 3 +
             (2 * a / 3 - 2 * c / 3)**2 / 3)).simplify() == 0
    raises(ValueError, lambda: E(X[1], Eq(X[2], 1)))

    #testing queries with multiple RandomIndexedSymbols
    T = Matrix([[Rational(5, 10),
                 Rational(3, 10),
                 Rational(2, 10)],
                [Rational(2, 10),
                 Rational(7, 10),
                 Rational(1, 10)],
                [Rational(3, 10),
                 Rational(3, 10),
                 Rational(4, 10)]])
    Y = DiscreteMarkovChain("Y", [0, 1, 2], T)
    assert P(Eq(Y[7], Y[5]), Eq(Y[2], 0)).round(5) == Float(0.44428, 5)
    assert P(Gt(Y[3], Y[1]), Eq(Y[0], 0)).round(2) == Float(0.36, 2)
    assert P(Le(Y[5], Y[10]), Eq(Y[4], 2)).round(6) == Float(0.583120, 6)
    assert Float(P(Eq(Y[10], Y[5]), Eq(Y[4], 1)),
                 14) == Float(1 - P(Ne(Y[10], Y[5]), Eq(Y[4], 1)), 14)
    assert Float(P(Gt(Y[8], Y[9]), Eq(Y[3], 2)),
                 14) == Float(1 - P(Le(Y[8], Y[9]), Eq(Y[3], 2)), 14)
    assert Float(P(Lt(Y[1], Y[4]), Eq(Y[0], 0)),
                 14) == Float(1 - P(Ge(Y[1], Y[4]), Eq(Y[0], 0)), 14)
    assert P(Eq(Y[5], Y[10]), Eq(Y[2], 1)) == P(Eq(Y[10], Y[5]), Eq(Y[2], 1))
    assert P(Gt(Y[1], Y[2]), Eq(Y[0], 1)) == P(Lt(Y[2], Y[1]), Eq(Y[0], 1))
    assert P(Ge(Y[7], Y[6]), Eq(Y[4], 1)) == P(Le(Y[6], Y[7]), Eq(Y[4], 1))

    #test symbolic queries
    a, b, c, d = symbols('a b c d')
    T = Matrix([[Rational(1, 10),
                 Rational(4, 10),
                 Rational(5, 10)],
                [Rational(3, 10),
                 Rational(4, 10),
                 Rational(3, 10)],
                [Rational(7, 10),
                 Rational(2, 10),
                 Rational(1, 10)]])
    Y = DiscreteMarkovChain("Y", [0, 1, 2], T)
    query = P(Eq(Y[a], b), Eq(Y[c], d))
    assert query.subs({
        a: 10,
        b: 2,
        c: 5,
        d: 1
    }).evalf().round(4) == P(Eq(Y[10], 2), Eq(Y[5], 1)).round(4)
    assert query.subs({
        a: 15,
        b: 0,
        c: 10,
        d: 1
    }).evalf().round(4) == P(Eq(Y[15], 0), Eq(Y[10], 1)).round(4)
    query_gt = P(Gt(Y[a], b), Eq(Y[c], d))
    query_le = P(Le(Y[a], b), Eq(Y[c], d))
    assert query_gt.subs({
        a: 5,
        b: 2,
        c: 1,
        d: 0
    }).evalf() + query_le.subs({
        a: 5,
        b: 2,
        c: 1,
        d: 0
    }).evalf() == 1
    query_ge = P(Ge(Y[a], b), Eq(Y[c], d))
    query_lt = P(Lt(Y[a], b), Eq(Y[c], d))
    assert query_ge.subs({
        a: 4,
        b: 1,
        c: 0,
        d: 2
    }).evalf() + query_lt.subs({
        a: 4,
        b: 1,
        c: 0,
        d: 2
    }).evalf() == 1

    #test issue 20078
    assert (2 * Y[1] + 3 * Y[1]).simplify() == 5 * Y[1]
    assert (2 * Y[1] - 3 * Y[1]).simplify() == -Y[1]
    assert (2 * (0.25 * Y[1])).simplify() == 0.5 * Y[1]
    assert ((2 * Y[1]) * (0.25 * Y[1])).simplify() == 0.5 * Y[1]**2
    assert (Y[1]**2 + Y[1]**3).simplify() == (Y[1] + 1) * Y[1]**2
Exemple #28
0
def test_ContinuousMarkovChain():
    T1 = Matrix([[S(-2), S(2), S.Zero], [S.Zero, S.NegativeOne, S.One],
                 [Rational(3, 2), Rational(3, 2),
                  S(-3)]])
    C1 = ContinuousMarkovChain('C', [0, 1, 2], T1)
    assert C1.limiting_distribution() == ImmutableMatrix(
        [[Rational(3, 19), Rational(12, 19),
          Rational(4, 19)]])

    T2 = Matrix([[-S.One, S.One, S.Zero], [S.One, -S.One, S.Zero],
                 [S.Zero, S.One, -S.One]])
    C2 = ContinuousMarkovChain('C', [0, 1, 2], T2)
    A, t = C2.generator_matrix, symbols('t', positive=True)
    assert C2.transition_probabilities(A)(t) == Matrix(
        [[S.Half + exp(-2 * t) / 2, S.Half - exp(-2 * t) / 2, 0],
         [S.Half - exp(-2 * t) / 2, S.Half + exp(-2 * t) / 2, 0],
         [
             S.Half - exp(-t) + exp(-2 * t) / 2, S.Half - exp(-2 * t) / 2,
             exp(-t)
         ]])
    with ignore_warnings(
            UserWarning):  ### TODO: Restore tests once warnings are removed
        assert P(Eq(C2(1), 1), Eq(C2(0), 1),
                 evaluate=False) == Probability(Eq(C2(1), 1), Eq(C2(0), 1))
    assert P(Eq(C2(1), 1), Eq(C2(0), 1)) == exp(-2) / 2 + S.Half
    assert P(
        Eq(C2(1), 0) & Eq(C2(2), 1) & Eq(C2(3), 1),
        Eq(P(Eq(C2(1), 0)),
           S.Half)) == (Rational(1, 4) - exp(-2) / 4) * (exp(-2) / 2 + S.Half)
    assert P(
        Not(Eq(C2(1), 0) & Eq(C2(2), 1) & Eq(C2(3), 2)) |
        (Eq(C2(1), 0) & Eq(C2(2), 1) & Eq(C2(3), 2)),
        Eq(P(Eq(C2(1), 0)), Rational(1, 4))
        & Eq(P(Eq(C2(1), 1)), Rational(1, 4))) is S.One
    assert E(C2(Rational(3, 2)),
             Eq(C2(0), 2)) == -exp(-3) / 2 + 2 * exp(Rational(-3, 2)) + S.Half
    assert variance(C2(Rational(3, 2)), Eq(
        C2(0),
        1)) == ((S.Half - exp(-3) / 2)**2 * (exp(-3) / 2 + S.Half) +
                (Rational(-1, 2) - exp(-3) / 2)**2 * (S.Half - exp(-3) / 2))
    raises(KeyError, lambda: P(Eq(C2(1), 0), Eq(P(Eq(C2(1), 1)), S.Half)))
    assert P(Eq(C2(1), 0), Eq(P(Eq(C2(5), 1)),
                              S.Half)) == Probability(Eq(C2(1), 0))
    TS1 = MatrixSymbol('G', 3, 3)
    CS1 = ContinuousMarkovChain('C', [0, 1, 2], TS1)
    A = CS1.generator_matrix
    assert CS1.transition_probabilities(A)(t) == exp(t * A)

    C3 = ContinuousMarkovChain(
        'C', [Symbol('0'), Symbol('1'), Symbol('2')], T2)
    assert P(Eq(C3(1), 1), Eq(C3(0), 1)) == exp(-2) / 2 + S.Half
    assert P(Eq(C3(1), Symbol('1')), Eq(C3(0),
                                        Symbol('1'))) == exp(-2) / 2 + S.Half

    #test probability queries
    G = Matrix([[-S(1), Rational(1, 10),
                 Rational(9, 10)], [Rational(2, 5), -S(1),
                                    Rational(3, 5)],
                [Rational(1, 2), Rational(1, 2), -S(1)]])
    C = ContinuousMarkovChain('C', state_space=[0, 1, 2], gen_mat=G)
    assert P(Eq(C(7.385), C(3.19)), Eq(C(0.862),
                                       0)).round(5) == Float(0.35469, 5)
    assert P(Gt(C(98.715), C(19.807)), Eq(C(11.314),
                                          2)).round(5) == Float(0.32452, 5)
    assert P(Le(C(5.9), C(10.112)), Eq(C(4), 1)).round(6) == Float(0.675214, 6)
    assert Float(P(Eq(C(7.32), C(2.91)), Eq(C(2.63), 1)),
                 14) == Float(1 - P(Ne(C(7.32), C(2.91)), Eq(C(2.63), 1)), 14)
    assert Float(P(Gt(C(3.36), C(1.101)), Eq(C(0.8), 2)),
                 14) == Float(1 - P(Le(C(3.36), C(1.101)), Eq(C(0.8), 2)), 14)
    assert Float(P(Lt(C(4.9), C(2.79)), Eq(C(1.61), 0)),
                 14) == Float(1 - P(Ge(C(4.9), C(2.79)), Eq(C(1.61), 0)), 14)
    assert P(Eq(C(5.243), C(10.912)), Eq(C(2.174),
                                         1)) == P(Eq(C(10.912), C(5.243)),
                                                  Eq(C(2.174), 1))
    assert P(Gt(C(2.344), C(9.9)), Eq(C(1.102),
                                      1)) == P(Lt(C(9.9), C(2.344)),
                                               Eq(C(1.102), 1))
    assert P(Ge(C(7.87), C(1.008)), Eq(C(0.153),
                                       1)) == P(Le(C(1.008), C(7.87)),
                                                Eq(C(0.153), 1))

    #test symbolic queries
    a, b, c, d = symbols('a b c d')
    query = P(Eq(C(a), b), Eq(C(c), d))
    assert query.subs({
        a: 3.65,
        b: 2,
        c: 1.78,
        d: 1
    }).evalf().round(10) == P(Eq(C(3.65), 2), Eq(C(1.78), 1)).round(10)
    query_gt = P(Gt(C(a), b), Eq(C(c), d))
    query_le = P(Le(C(a), b), Eq(C(c), d))
    assert query_gt.subs({
        a: 13.2,
        b: 0,
        c: 3.29,
        d: 2
    }).evalf() + query_le.subs({
        a: 13.2,
        b: 0,
        c: 3.29,
        d: 2
    }).evalf() == 1
    query_ge = P(Ge(C(a), b), Eq(C(c), d))
    query_lt = P(Lt(C(a), b), Eq(C(c), d))
    assert query_ge.subs({
        a: 7.43,
        b: 1,
        c: 1.45,
        d: 0
    }).evalf() + query_lt.subs({
        a: 7.43,
        b: 1,
        c: 1.45,
        d: 0
    }).evalf() == 1

    #test issue 20078
    assert (2 * C(1) + 3 * C(1)).simplify() == 5 * C(1)
    assert (2 * C(1) - 3 * C(1)).simplify() == -C(1)
    assert (2 * (0.25 * C(1))).simplify() == 0.5 * C(1)
    assert (2 * C(1) * 0.25 * C(1)).simplify() == 0.5 * C(1)**2
    assert (C(1)**2 + C(1)**3).simplify() == (C(1) + 1) * C(1)**2
Exemple #29
0
def test_new_relational():
    x = Symbol('x')

    assert Eq(x, 0) == Relational(x, 0)  # None ==> Equality
    assert Eq(x, 0) == Relational(x, 0, '==')
    assert Eq(x, 0) == Relational(x, 0, 'eq')
    assert Eq(x, 0) == Equality(x, 0)

    assert Eq(x, 0) != Relational(x, 1)  # None ==> Equality
    assert Eq(x, 0) != Relational(x, 1, '==')
    assert Eq(x, 0) != Relational(x, 1, 'eq')
    assert Eq(x, 0) != Equality(x, 1)

    assert Eq(x, -1) == Relational(x, -1)  # None ==> Equality
    assert Eq(x, -1) == Relational(x, -1, '==')
    assert Eq(x, -1) == Relational(x, -1, 'eq')
    assert Eq(x, -1) == Equality(x, -1)
    assert Eq(x, -1) != Relational(x, 1)  # None ==> Equality
    assert Eq(x, -1) != Relational(x, 1, '==')
    assert Eq(x, -1) != Relational(x, 1, 'eq')
    assert Eq(x, -1) != Equality(x, 1)

    assert Ne(x, 0) == Relational(x, 0, '!=')
    assert Ne(x, 0) == Relational(x, 0, '<>')
    assert Ne(x, 0) == Relational(x, 0, 'ne')
    assert Ne(x, 0) == Unequality(x, 0)
    assert Ne(x, 0) != Relational(x, 1, '!=')
    assert Ne(x, 0) != Relational(x, 1, '<>')
    assert Ne(x, 0) != Relational(x, 1, 'ne')
    assert Ne(x, 0) != Unequality(x, 1)

    assert Ge(x, 0) == Relational(x, 0, '>=')
    assert Ge(x, 0) == Relational(x, 0, 'ge')
    assert Ge(x, 0) == GreaterThan(x, 0)
    assert Ge(x, 1) != Relational(x, 0, '>=')
    assert Ge(x, 1) != Relational(x, 0, 'ge')
    assert Ge(x, 1) != GreaterThan(x, 0)
    assert (x >= 1) == Relational(x, 1, '>=')
    assert (x >= 1) == Relational(x, 1, 'ge')
    assert (x >= 1) == GreaterThan(x, 1)
    assert (x >= 0) != Relational(x, 1, '>=')
    assert (x >= 0) != Relational(x, 1, 'ge')
    assert (x >= 0) != GreaterThan(x, 1)

    assert Le(x, 0) == Relational(x, 0, '<=')
    assert Le(x, 0) == Relational(x, 0, 'le')
    assert Le(x, 0) == LessThan(x, 0)
    assert Le(x, 1) != Relational(x, 0, '<=')
    assert Le(x, 1) != Relational(x, 0, 'le')
    assert Le(x, 1) != LessThan(x, 0)
    assert (x <= 1) == Relational(x, 1, '<=')
    assert (x <= 1) == Relational(x, 1, 'le')
    assert (x <= 1) == LessThan(x, 1)
    assert (x <= 0) != Relational(x, 1, '<=')
    assert (x <= 0) != Relational(x, 1, 'le')
    assert (x <= 0) != LessThan(x, 1)

    assert Gt(x, 0) == Relational(x, 0, '>')
    assert Gt(x, 0) == Relational(x, 0, 'gt')
    assert Gt(x, 0) == StrictGreaterThan(x, 0)
    assert Gt(x, 1) != Relational(x, 0, '>')
    assert Gt(x, 1) != Relational(x, 0, 'gt')
    assert Gt(x, 1) != StrictGreaterThan(x, 0)
    assert (x > 1) == Relational(x, 1, '>')
    assert (x > 1) == Relational(x, 1, 'gt')
    assert (x > 1) == StrictGreaterThan(x, 1)
    assert (x > 0) != Relational(x, 1, '>')
    assert (x > 0) != Relational(x, 1, 'gt')
    assert (x > 0) != StrictGreaterThan(x, 1)

    assert Lt(x, 0) == Relational(x, 0, '<')
    assert Lt(x, 0) == Relational(x, 0, 'lt')
    assert Lt(x, 0) == StrictLessThan(x, 0)
    assert Lt(x, 1) != Relational(x, 0, '<')
    assert Lt(x, 1) != Relational(x, 0, 'lt')
    assert Lt(x, 1) != StrictLessThan(x, 0)
    assert (x < 1) == Relational(x, 1, '<')
    assert (x < 1) == Relational(x, 1, 'lt')
    assert (x < 1) == StrictLessThan(x, 1)
    assert (x < 0) != Relational(x, 1, '<')
    assert (x < 0) != Relational(x, 1, 'lt')
    assert (x < 0) != StrictLessThan(x, 1)

    # finally, some fuzz testing
    from sympy.core.random import randint
    for i in range(100):
        while 1:
            strtype, length = (chr, 65535) if randint(0, 1) else (chr, 255)
            relation_type = strtype(randint(0, length))
            if randint(0, 1):
                relation_type += strtype(randint(0, length))
            if relation_type not in ('==', 'eq', '!=', '<>', 'ne', '>=', 'ge',
                                     '<=', 'le', '>', 'gt', '<', 'lt', ':=',
                                     '+=', '-=', '*=', '/=', '%='):
                break

        raises(ValueError, lambda: Relational(x, 1, relation_type))
    assert all(Relational(x, 0, op).rel_op == '==' for op in ('eq', '=='))
    assert all(
        Relational(x, 0, op).rel_op == '!=' for op in ('ne', '<>', '!='))
    assert all(Relational(x, 0, op).rel_op == '>' for op in ('gt', '>'))
    assert all(Relational(x, 0, op).rel_op == '<' for op in ('lt', '<'))
    assert all(Relational(x, 0, op).rel_op == '>=' for op in ('ge', '>='))
    assert all(Relational(x, 0, op).rel_op == '<=' for op in ('le', '<='))
Exemple #30
0
def test_rich_cmp():
    assert (x < y) == Lt(x, y)
    assert (x <= y) == Le(x, y)
    assert (x > y) == Gt(x, y)
    assert (x >= y) == Ge(x, y)