Exemple #1
0
def test_to_algebraic_integer():
    a = AlgebraicNumber(sqrt(3), gen=x).to_algebraic_integer()

    assert a.minpoly == x**2 - 3
    assert a.root == sqrt(3)
    assert a.rep == DMP([QQ(1), QQ(0)], QQ)

    a = AlgebraicNumber(2 * sqrt(3), gen=x).to_algebraic_integer()

    assert a.minpoly == x**2 - 12
    assert a.root == 2 * sqrt(3)
    assert a.rep == DMP([QQ(1), QQ(0)], QQ)

    a = AlgebraicNumber(sqrt(3) / 2, gen=x).to_algebraic_integer()

    assert a.minpoly == x**2 - 12
    assert a.root == 2 * sqrt(3)
    assert a.rep == DMP([QQ(1), QQ(0)], QQ)

    a = AlgebraicNumber(sqrt(3) / 2, [S(7) / 19, 3],
                        gen=x).to_algebraic_integer()

    assert a.minpoly == x**2 - 12
    assert a.root == 2 * sqrt(3)
    assert a.rep == DMP([QQ(7, 19), QQ(3)], QQ)
def test_to_number_field():
    assert to_number_field(sqrt(2)) == AlgebraicNumber(sqrt(2))
    assert to_number_field([sqrt(2), sqrt(3)]) == AlgebraicNumber(sqrt(2)+sqrt(3))

    a = AlgebraicNumber(sqrt(2)+sqrt(3), [S(1)/2, S(0), -S(9)/2, S(0)])

    assert to_number_field(sqrt(2), sqrt(2)+sqrt(3)) == a
    assert to_number_field(sqrt(2), AlgebraicNumber(sqrt(2)+sqrt(3))) == a

    raises(IsomorphismFailed, "to_number_field(sqrt(2), sqrt(3))")
def test_to_number_field():
    assert to_number_field(sqrt(2)) == AlgebraicNumber(sqrt(2))
    assert to_number_field(
        [sqrt(2), sqrt(3)]) == AlgebraicNumber(sqrt(2) + sqrt(3))

    a = AlgebraicNumber(sqrt(2) + sqrt(3), [S.Half, S.Zero, Rational(-9, 2), S.Zero])

    assert to_number_field(sqrt(2), sqrt(2) + sqrt(3)) == a
    assert to_number_field(sqrt(2), AlgebraicNumber(sqrt(2) + sqrt(3))) == a

    raises(IsomorphismFailed, lambda: to_number_field(sqrt(2), sqrt(3)))
Exemple #4
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def test_field_isomorphism_pslq():
    a = AlgebraicNumber(I)
    b = AlgebraicNumber(I * sqrt(3))

    raises(NotImplementedError, lambda: field_isomorphism_pslq(a, b))

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(3))
    c = AlgebraicNumber(sqrt(7))
    d = AlgebraicNumber(sqrt(2) + sqrt(3))
    e = AlgebraicNumber(sqrt(2) + sqrt(3) + sqrt(7))

    assert field_isomorphism_pslq(a, a) == [1, 0]
    assert field_isomorphism_pslq(a, b) is None
    assert field_isomorphism_pslq(a, c) is None
    assert field_isomorphism_pslq(a, d) == [Q(1, 2), 0, -Q(9, 2), 0]
    assert field_isomorphism_pslq(
        a, e) == [Q(1, 80), 0, -Q(1, 2), 0,
                  Q(59, 20), 0]

    assert field_isomorphism_pslq(b, a) is None
    assert field_isomorphism_pslq(b, b) == [1, 0]
    assert field_isomorphism_pslq(b, c) is None
    assert field_isomorphism_pslq(b, d) == [-Q(1, 2), 0, Q(11, 2), 0]
    assert field_isomorphism_pslq(b, e) == [
        -Q(3, 640), 0,
        Q(67, 320), 0, -Q(297, 160), 0,
        Q(313, 80), 0
    ]

    assert field_isomorphism_pslq(c, a) is None
    assert field_isomorphism_pslq(c, b) is None
    assert field_isomorphism_pslq(c, c) == [1, 0]
    assert field_isomorphism_pslq(c, d) is None
    assert field_isomorphism_pslq(c, e) == [
        Q(3, 640), 0, -Q(71, 320), 0,
        Q(377, 160), 0, -Q(469, 80), 0
    ]

    assert field_isomorphism_pslq(d, a) is None
    assert field_isomorphism_pslq(d, b) is None
    assert field_isomorphism_pslq(d, c) is None
    assert field_isomorphism_pslq(d, d) == [1, 0]
    assert field_isomorphism_pslq(d, e) == [
        -Q(3, 640), 0,
        Q(71, 320), 0, -Q(377, 160), 0,
        Q(549, 80), 0
    ]

    assert field_isomorphism_pslq(e, a) is None
    assert field_isomorphism_pslq(e, b) is None
    assert field_isomorphism_pslq(e, c) is None
    assert field_isomorphism_pslq(e, d) is None
    assert field_isomorphism_pslq(e, e) == [1, 0]

    f = AlgebraicNumber(3 * sqrt(2) + 8 * sqrt(7) - 5)

    assert field_isomorphism_pslq(
        f, e) == [Q(3, 80), 0, -Q(139, 80), 0,
                  Q(347, 20), 0, -Q(761, 20), -5]
Exemple #5
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def test_AlgebraicNumber():
    minpoly, root = x**2 - 2, sqrt(2)

    a = AlgebraicNumber(root, gen=x)

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased is False

    assert a.coeffs() == [S(1), S(0)]
    assert a.native_coeffs() == [QQ(1), QQ(0)]

    a = AlgebraicNumber(root, gen=x, alias='y')

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias == Symbol('y')
    assert a.minpoly == minpoly

    assert a.is_aliased is True

    a = AlgebraicNumber(root, gen=x, alias=Symbol('y'))

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias == Symbol('y')
    assert a.minpoly == minpoly

    assert a.is_aliased is True

    assert AlgebraicNumber(sqrt(2), []).rep == DMP([], QQ)

    assert AlgebraicNumber(sqrt(2), [8]).rep == DMP([QQ(8)], QQ)
    assert AlgebraicNumber(sqrt(2), [S(8) / 3]).rep == DMP([QQ(8, 3)], QQ)

    assert AlgebraicNumber(sqrt(2), [7, 3]).rep == DMP([QQ(7), QQ(3)], QQ)
    assert AlgebraicNumber(sqrt(2), [S(7) / 9, S(3) / 2]).rep == DMP(
        [QQ(7, 9), QQ(3, 2)], QQ)

    assert AlgebraicNumber(sqrt(2), [1, 2, 3]).rep == DMP([QQ(2), QQ(5)], QQ)

    a = AlgebraicNumber(AlgebraicNumber(root, gen=x), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased is False

    assert a.coeffs() == [S(1), S(2)]
    assert a.native_coeffs() == [QQ(1), QQ(2)]

    a = AlgebraicNumber((minpoly, root), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased is False

    a = AlgebraicNumber((Poly(minpoly), root), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased is False

    assert AlgebraicNumber(sqrt(3)).rep == DMP([QQ(1), QQ(0)], QQ)
    assert AlgebraicNumber(-sqrt(3)).rep == DMP([-QQ(1), QQ(0)], QQ)

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(2))

    assert a == b

    c = AlgebraicNumber(sqrt(2), gen=x)
    d = AlgebraicNumber(sqrt(2), gen=x)

    assert a == b
    assert a == c

    a = AlgebraicNumber(sqrt(2), [1, 2])
    b = AlgebraicNumber(sqrt(2), [1, 3])

    assert a != b and a != sqrt(2) + 3

    assert (a == x) is False and (a != x) is True

    a = AlgebraicNumber(sqrt(2), [1, 0])
    b = AlgebraicNumber(sqrt(2), [1, 0], alias=y)

    assert a.as_poly(x) == Poly(x)
    assert b.as_poly() == Poly(y)

    assert a.as_expr() == sqrt(2)
    assert a.as_expr(x) == x
    assert b.as_expr() == sqrt(2)
    assert b.as_expr(x) == x

    a = AlgebraicNumber(sqrt(2), [2, 3])
    b = AlgebraicNumber(sqrt(2), [2, 3], alias=y)

    p = a.as_poly()

    assert p == Poly(2 * p.gen + 3)

    assert a.as_poly(x) == Poly(2 * x + 3)
    assert b.as_poly() == Poly(2 * y + 3)

    assert a.as_expr() == 2 * sqrt(2) + 3
    assert a.as_expr(x) == 2 * x + 3
    assert b.as_expr() == 2 * sqrt(2) + 3
    assert b.as_expr(x) == 2 * x + 3

    a = AlgebraicNumber(sqrt(2))
    b = to_number_field(sqrt(2))
    assert a.args == b.args == (sqrt(2), Tuple())
    b = AlgebraicNumber(sqrt(2), alias='alpha')
    assert b.args == (sqrt(2), Tuple(), Symbol('alpha'))

    a = AlgebraicNumber(sqrt(2), [1, 2, 3])
    assert a.args == (sqrt(2), Tuple(1, 2, 3))
Exemple #6
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def test_minimal_polynomial():
    assert minimal_polynomial(-7, x) == x + 7
    assert minimal_polynomial(-1, x) == x + 1
    assert minimal_polynomial(0, x) == x
    assert minimal_polynomial(1, x) == x - 1
    assert minimal_polynomial(7, x) == x - 7

    assert minimal_polynomial(sqrt(2), x) == x**2 - 2
    assert minimal_polynomial(sqrt(5), x) == x**2 - 5
    assert minimal_polynomial(sqrt(6), x) == x**2 - 6

    assert minimal_polynomial(2 * sqrt(2), x) == x**2 - 8
    assert minimal_polynomial(3 * sqrt(5), x) == x**2 - 45
    assert minimal_polynomial(4 * sqrt(6), x) == x**2 - 96

    assert minimal_polynomial(2 * sqrt(2) + 3, x) == x**2 - 6 * x + 1
    assert minimal_polynomial(3 * sqrt(5) + 6, x) == x**2 - 12 * x - 9
    assert minimal_polynomial(4 * sqrt(6) + 7, x) == x**2 - 14 * x - 47

    assert minimal_polynomial(2 * sqrt(2) - 3, x) == x**2 + 6 * x + 1
    assert minimal_polynomial(3 * sqrt(5) - 6, x) == x**2 + 12 * x - 9
    assert minimal_polynomial(4 * sqrt(6) - 7, x) == x**2 + 14 * x - 47

    assert minimal_polynomial(sqrt(1 + sqrt(6)), x) == x**4 - 2 * x**2 - 5
    assert minimal_polynomial(sqrt(I + sqrt(6)), x) == x**8 - 10 * x**4 + 49

    assert minimal_polynomial(2 * I + sqrt(2 + I),
                              x) == x**4 + 4 * x**2 + 8 * x + 37

    assert minimal_polynomial(sqrt(2) + sqrt(3), x) == x**4 - 10 * x**2 + 1
    assert minimal_polynomial(sqrt(2) + sqrt(3) + sqrt(6),
                              x) == x**4 - 22 * x**2 - 48 * x - 23

    a = 1 - 9 * sqrt(2) + 7 * sqrt(3)

    assert minimal_polynomial(
        1 / a, x) == 392 * x**4 - 1232 * x**3 + 612 * x**2 + 4 * x - 1
    assert minimal_polynomial(
        1 / sqrt(a), x) == 392 * x**8 - 1232 * x**6 + 612 * x**4 + 4 * x**2 - 1

    raises(NotAlgebraic, lambda: minimal_polynomial(oo, x))
    raises(NotAlgebraic, lambda: minimal_polynomial(2**y, x))
    raises(NotAlgebraic, lambda: minimal_polynomial(sin(1), x))

    assert minimal_polynomial(sqrt(2)).dummy_eq(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x) == x**2 - 2

    assert minimal_polynomial(sqrt(2), polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x, polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x, polys=True,
                              compose=False) == Poly(x**2 - 2)

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(3))

    assert minimal_polynomial(a, x) == x**2 - 2
    assert minimal_polynomial(b, x) == x**2 - 3

    assert minimal_polynomial(a, x, polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(b, x, polys=True) == Poly(x**2 - 3)

    assert minimal_polynomial(sqrt(a / 2 + 17),
                              x) == 2 * x**4 - 68 * x**2 + 577
    assert minimal_polynomial(sqrt(b / 2 + 17),
                              x) == 4 * x**4 - 136 * x**2 + 1153

    a, b = sqrt(2) / 3 + 7, AlgebraicNumber(sqrt(2) / 3 + 7)

    f = 81*x**8 - 2268*x**6 - 4536*x**5 + 22644*x**4 + 63216*x**3 - \
        31608*x**2 - 189648*x + 141358

    assert minimal_polynomial(sqrt(a) + sqrt(sqrt(a)), x) == f
    assert minimal_polynomial(sqrt(b) + sqrt(sqrt(b)), x) == f

    assert minimal_polynomial(a**Q(3, 2),
                              x) == 729 * x**4 - 506898 * x**2 + 84604519

    # issue 2895
    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)))''')
    assert minimal_polynomial(eq, x) == 8000 * x**2 - 1

    ex = 1 + sqrt(2) + sqrt(3)
    mp = minimal_polynomial(ex, x)
    assert mp == x**4 - 4 * x**3 - 4 * x**2 + 16 * x - 8

    ex = 1 / (1 + sqrt(2) + sqrt(3))
    mp = minimal_polynomial(ex, x)
    assert mp == 8 * x**4 - 16 * x**3 + 4 * x**2 + 4 * x - 1

    p = (expand((1 + sqrt(2) - 2 * sqrt(3) + sqrt(7))**3))**Rational(1, 3)
    mp = minimal_polynomial(p, x)
    assert mp == x**8 - 8 * x**7 - 56 * x**6 + 448 * x**5 + 480 * x**4 - 5056 * x**3 + 1984 * x**2 + 7424 * x - 3008
    p = expand((1 + sqrt(2) - 2 * sqrt(3) + sqrt(7))**3)
    mp = minimal_polynomial(p, x)
    assert mp == x**8 - 512 * x**7 - 118208 * x**6 + 31131136 * x**5 + 647362560 * x**4 - 56026611712 * x**3 + 116994310144 * x**2 + 404854931456 * x - 27216576512

    assert minimal_polynomial(S("-sqrt(5)/2 - 1/2 + (-sqrt(5)/2 - 1/2)**2"),
                              x) == x - 1
    a = 1 + sqrt(2)
    assert minimal_polynomial((a * sqrt(2) + a)**3, x) == x**2 - 198 * x + 1

    p = 1 / (1 + sqrt(2) + sqrt(3))
    assert minimal_polynomial(
        p, x, compose=False) == 8 * x**4 - 16 * x**3 + 4 * x**2 + 4 * x - 1

    p = 2 / (1 + sqrt(2) + sqrt(3))
    assert minimal_polynomial(
        p, x, compose=False) == x**4 - 4 * x**3 + 2 * x**2 + 4 * x - 2

    assert minimal_polynomial(1 + sqrt(2) * I, x,
                              compose=False) == x**2 - 2 * x + 3
    assert minimal_polynomial(1 / (1 + sqrt(2)) + 1, x,
                              compose=False) == x**2 - 2
    assert minimal_polynomial(sqrt(2) * I + I * (1 + sqrt(2)),
                              x,
                              compose=False) == x**4 + 18 * x**2 + 49
Exemple #7
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def test_field_isomorphism():
    assert field_isomorphism(3, sqrt(2)) == [3]

    assert field_isomorphism(I * sqrt(3), I * sqrt(3) / 2) == [2, 0]
    assert field_isomorphism(-I * sqrt(3), I * sqrt(3) / 2) == [-2, 0]

    assert field_isomorphism(I * sqrt(3), -I * sqrt(3) / 2) == [-2, 0]
    assert field_isomorphism(-I * sqrt(3), -I * sqrt(3) / 2) == [2, 0]

    assert field_isomorphism(2 * I * sqrt(3) / 7,
                             5 * I * sqrt(3) / 3) == [S(6) / 35, 0]
    assert field_isomorphism(-2 * I * sqrt(3) / 7,
                             5 * I * sqrt(3) / 3) == [-S(6) / 35, 0]

    assert field_isomorphism(2 * I * sqrt(3) / 7,
                             -5 * I * sqrt(3) / 3) == [-S(6) / 35, 0]
    assert field_isomorphism(-2 * I * sqrt(3) / 7,
                             -5 * I * sqrt(3) / 3) == [S(6) / 35, 0]

    assert field_isomorphism(2 * I * sqrt(3) / 7 + 27,
                             5 * I * sqrt(3) / 3) == [S(6) / 35, 27]
    assert field_isomorphism(-2 * I * sqrt(3) / 7 + 27,
                             5 * I * sqrt(3) / 3) == [-S(6) / 35, 27]

    assert field_isomorphism(2 * I * sqrt(3) / 7 + 27,
                             -5 * I * sqrt(3) / 3) == [-S(6) / 35, 27]
    assert field_isomorphism(-2 * I * sqrt(3) / 7 + 27,
                             -5 * I * sqrt(3) / 3) == [S(6) / 35, 27]

    p = AlgebraicNumber(sqrt(2) + sqrt(3))
    q = AlgebraicNumber(-sqrt(2) + sqrt(3))
    r = AlgebraicNumber(sqrt(2) - sqrt(3))
    s = AlgebraicNumber(-sqrt(2) - sqrt(3))

    pos_coeffs = [S(1) / 2, S(0), -S(9) / 2, S(0)]
    neg_coeffs = [-S(1) / 2, S(0), S(9) / 2, S(0)]

    a = AlgebraicNumber(sqrt(2))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == pos_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_coeffs
    assert field_isomorphism(a, s, fast=True) == neg_coeffs

    assert field_isomorphism(a, p, fast=False) == pos_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_coeffs
    assert field_isomorphism(a, s, fast=False) == neg_coeffs

    a = AlgebraicNumber(-sqrt(2))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == neg_coeffs
    assert field_isomorphism(a, q, fast=True) == pos_coeffs
    assert field_isomorphism(a, r, fast=True) == neg_coeffs
    assert field_isomorphism(a, s, fast=True) == pos_coeffs

    assert field_isomorphism(a, p, fast=False) == neg_coeffs
    assert field_isomorphism(a, q, fast=False) == pos_coeffs
    assert field_isomorphism(a, r, fast=False) == neg_coeffs
    assert field_isomorphism(a, s, fast=False) == pos_coeffs

    pos_coeffs = [S(1) / 2, S(0), -S(11) / 2, S(0)]
    neg_coeffs = [-S(1) / 2, S(0), S(11) / 2, S(0)]

    a = AlgebraicNumber(sqrt(3))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == neg_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_coeffs
    assert field_isomorphism(a, s, fast=True) == pos_coeffs

    assert field_isomorphism(a, p, fast=False) == neg_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_coeffs
    assert field_isomorphism(a, s, fast=False) == pos_coeffs

    a = AlgebraicNumber(-sqrt(3))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == pos_coeffs
    assert field_isomorphism(a, q, fast=True) == pos_coeffs
    assert field_isomorphism(a, r, fast=True) == neg_coeffs
    assert field_isomorphism(a, s, fast=True) == neg_coeffs

    assert field_isomorphism(a, p, fast=False) == pos_coeffs
    assert field_isomorphism(a, q, fast=False) == pos_coeffs
    assert field_isomorphism(a, r, fast=False) == neg_coeffs
    assert field_isomorphism(a, s, fast=False) == neg_coeffs

    pos_coeffs = [S(3) / 2, S(0), -S(33) / 2, -S(8)]
    neg_coeffs = [-S(3) / 2, S(0), S(33) / 2, -S(8)]

    a = AlgebraicNumber(3 * sqrt(3) - 8)

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == neg_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_coeffs
    assert field_isomorphism(a, s, fast=True) == pos_coeffs

    assert field_isomorphism(a, p, fast=False) == neg_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_coeffs
    assert field_isomorphism(a, s, fast=False) == pos_coeffs

    a = AlgebraicNumber(3 * sqrt(2) + 2 * sqrt(3) + 1)

    pos_1_coeffs = [S(1) / 2, S(0), -S(5) / 2, S(1)]
    neg_5_coeffs = [-S(5) / 2, S(0), S(49) / 2, S(1)]
    pos_5_coeffs = [S(5) / 2, S(0), -S(49) / 2, S(1)]
    neg_1_coeffs = [-S(1) / 2, S(0), S(5) / 2, S(1)]

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == pos_1_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_5_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_5_coeffs
    assert field_isomorphism(a, s, fast=True) == neg_1_coeffs

    assert field_isomorphism(a, p, fast=False) == pos_1_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_5_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_5_coeffs
    assert field_isomorphism(a, s, fast=False) == neg_1_coeffs

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(3))
    c = AlgebraicNumber(sqrt(7))

    assert is_isomorphism_possible(a, b) is True
    assert is_isomorphism_possible(b, a) is True

    assert is_isomorphism_possible(c, p) is False

    assert field_isomorphism(sqrt(2), sqrt(3), fast=True) is None
    assert field_isomorphism(sqrt(3), sqrt(2), fast=True) is None

    assert field_isomorphism(sqrt(2), sqrt(3), fast=False) is None
    assert field_isomorphism(sqrt(3), sqrt(2), fast=False) is None
Exemple #8
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 def to_sympy(self, a):
     """Convert `a` to a SymPy object. """
     from sympy.polys.numberfields import AlgebraicNumber
     return AlgebraicNumber(self.ext, a).as_expr()
Exemple #9
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def test_pickling_polys_numberfields():
    from sympy.polys.numberfields import AlgebraicNumber

    for c in (AlgebraicNumber, AlgebraicNumber(sqrt(3))):
        check(c, check_attr=False)
Exemple #10
0
def test_sympy__polys__numberfields__AlgebraicNumber():
    from sympy.polys.numberfields import AlgebraicNumber
    assert _test_args(AlgebraicNumber(sqrt(2), [1, 2, 3]))
def test_AlgebraicNumber():
    minpoly, root = x**2 - 2, sqrt(2)

    a = AlgebraicNumber(root, gen=x)

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly
    assert a.is_number

    assert a.is_aliased is False

    assert a.coeffs() == [S(1), S(0)]
    assert a.native_coeffs() == [QQ(1), QQ(0)]

    a = AlgebraicNumber(root, gen=x, alias='y')

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias == Symbol('y')
    assert a.minpoly == minpoly
    assert a.is_number

    assert a.is_aliased is True

    a = AlgebraicNumber(root, gen=x, alias=Symbol('y'))

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias == Symbol('y')
    assert a.minpoly == minpoly
    assert a.is_number

    assert a.is_aliased is True

    assert AlgebraicNumber(sqrt(2), []).rep == DMP([], QQ)
    assert AlgebraicNumber(sqrt(2), ()).rep == DMP([], QQ)
    assert AlgebraicNumber(sqrt(2), (0, 0)).rep == DMP([], QQ)

    assert AlgebraicNumber(sqrt(2), [8]).rep == DMP([QQ(8)], QQ)
    assert AlgebraicNumber(sqrt(2), [S(8)/3]).rep == DMP([QQ(8, 3)], QQ)

    assert AlgebraicNumber(sqrt(2), [7, 3]).rep == DMP([QQ(7), QQ(3)], QQ)
    assert AlgebraicNumber(
        sqrt(2), [S(7)/9, S(3)/2]).rep == DMP([QQ(7, 9), QQ(3, 2)], QQ)

    assert AlgebraicNumber(sqrt(2), [1, 2, 3]).rep == DMP([QQ(2), QQ(5)], QQ)

    a = AlgebraicNumber(AlgebraicNumber(root, gen=x), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly
    assert a.is_number

    assert a.is_aliased is False

    assert a.coeffs() == [S(1), S(2)]
    assert a.native_coeffs() == [QQ(1), QQ(2)]

    a = AlgebraicNumber((minpoly, root), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly
    assert a.is_number

    assert a.is_aliased is False

    a = AlgebraicNumber((Poly(minpoly), root), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly
    assert a.is_number

    assert a.is_aliased is False

    assert AlgebraicNumber( sqrt(3)).rep == DMP([ QQ(1), QQ(0)], QQ)
    assert AlgebraicNumber(-sqrt(3)).rep == DMP([-QQ(1), QQ(0)], QQ)

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(2))

    assert a == b

    c = AlgebraicNumber(sqrt(2), gen=x)
    d = AlgebraicNumber(sqrt(2), gen=x)

    assert a == b
    assert a == c

    a = AlgebraicNumber(sqrt(2), [1, 2])
    b = AlgebraicNumber(sqrt(2), [1, 3])

    assert a != b and a != sqrt(2) + 3

    assert (a == x) is False and (a != x) is True

    a = AlgebraicNumber(sqrt(2), [1, 0])
    b = AlgebraicNumber(sqrt(2), [1, 0], alias=y)

    assert a.as_poly(x) == Poly(x)
    assert b.as_poly() == Poly(y)

    assert a.as_expr() == sqrt(2)
    assert a.as_expr(x) == x
    assert b.as_expr() == sqrt(2)
    assert b.as_expr(x) == x

    a = AlgebraicNumber(sqrt(2), [2, 3])
    b = AlgebraicNumber(sqrt(2), [2, 3], alias=y)

    p = a.as_poly()

    assert p == Poly(2*p.gen + 3)

    assert a.as_poly(x) == Poly(2*x + 3)
    assert b.as_poly() == Poly(2*y + 3)

    assert a.as_expr() == 2*sqrt(2) + 3
    assert a.as_expr(x) == 2*x + 3
    assert b.as_expr() == 2*sqrt(2) + 3
    assert b.as_expr(x) == 2*x + 3

    a = AlgebraicNumber(sqrt(2))
    b = to_number_field(sqrt(2))
    assert a.args == b.args == (sqrt(2), Tuple(1, 0))
    b = AlgebraicNumber(sqrt(2), alias='alpha')
    assert b.args == (sqrt(2), Tuple(1, 0), Symbol('alpha'))

    a = AlgebraicNumber(sqrt(2), [1, 2, 3])
    assert a.args == (sqrt(2), Tuple(1, 2, 3))
def test_minimal_polynomial():
    assert minimal_polynomial(-7, x) == x + 7
    assert minimal_polynomial(-1, x) == x + 1
    assert minimal_polynomial( 0, x) == x
    assert minimal_polynomial( 1, x) == x - 1
    assert minimal_polynomial( 7, x) == x - 7

    assert minimal_polynomial(sqrt(2), x) == x**2 - 2
    assert minimal_polynomial(sqrt(5), x) == x**2 - 5
    assert minimal_polynomial(sqrt(6), x) == x**2 - 6

    assert minimal_polynomial(2*sqrt(2), x) == x**2 - 8
    assert minimal_polynomial(3*sqrt(5), x) == x**2 - 45
    assert minimal_polynomial(4*sqrt(6), x) == x**2 - 96

    assert minimal_polynomial(2*sqrt(2) + 3, x) == x**2 -  6*x +  1
    assert minimal_polynomial(3*sqrt(5) + 6, x) == x**2 - 12*x -  9
    assert minimal_polynomial(4*sqrt(6) + 7, x) == x**2 - 14*x - 47

    assert minimal_polynomial(2*sqrt(2) - 3, x) == x**2 +  6*x +  1
    assert minimal_polynomial(3*sqrt(5) - 6, x) == x**2 + 12*x -  9
    assert minimal_polynomial(4*sqrt(6) - 7, x) == x**2 + 14*x - 47

    assert minimal_polynomial(sqrt(1 + sqrt(6)), x) == x**4 -  2*x**2 -  5
    assert minimal_polynomial(sqrt(I + sqrt(6)), x) == x**8 - 10*x**4 + 49

    assert minimal_polynomial(2*I + sqrt(2 + I), x) == x**4 + 4*x**2 + 8*x + 37

    assert minimal_polynomial(sqrt(2) + sqrt(3), x) == x**4 - 10*x**2 + 1
    assert minimal_polynomial(sqrt(2) + sqrt(3) + sqrt(6), x) == x**4 - 22*x**2 - 48*x - 23

    a = 1 - 9*sqrt(2) + 7*sqrt(3)

    assert minimal_polynomial(1/a, x) == 392*x**4 - 1232*x**3 + 612*x**2 + 4*x - 1
    assert minimal_polynomial(1/sqrt(a), x) == 392*x**8 - 1232*x**6 + 612*x**4 + 4*x**2 - 1

    raises(NotAlgebraic, "minimal_polynomial(y, x)")
    raises(NotAlgebraic, "minimal_polynomial(oo, x)")
    raises(NotAlgebraic, "minimal_polynomial(2**y, x)")
    raises(NotAlgebraic, "minimal_polynomial(sin(1), x)")

    assert minimal_polynomial(sqrt(2)).dummy_eq(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x) == x**2 - 2

    assert minimal_polynomial(sqrt(2), polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x, polys=True) == Poly(x**2 - 2)

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(3))

    assert minimal_polynomial(a, x) == x**2 - 2
    assert minimal_polynomial(b, x) == x**2 - 3

    assert minimal_polynomial(a, x, polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(b, x, polys=True) == Poly(x**2 - 3)

    assert minimal_polynomial(sqrt(a/2 + 17), x) == 2*x**4 -  68*x**2 +  577
    assert minimal_polynomial(sqrt(b/2 + 17), x) == 4*x**4 - 136*x**2 + 1153

    a, b = sqrt(2)/3 + 7, AlgebraicNumber(sqrt(2)/3 + 7)

    f = 81*x**8 - 2268*x**6 - 4536*x**5 + 22644*x**4 + 63216*x**3 - 31608*x**2 - 189648*x + 141358

    assert minimal_polynomial(sqrt(a) + sqrt(sqrt(a)), x) == f
    assert minimal_polynomial(sqrt(b) + sqrt(sqrt(b)), x) == f

    assert minimal_polynomial(a**Rational(3, 2), x) == 729*x**4 - 506898*x**2 + 84604519
Exemple #13
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def test_minimal_polynomial():
    assert minimal_polynomial(-7, x) == x + 7
    assert minimal_polynomial(-1, x) == x + 1
    assert minimal_polynomial(0, x) == x
    assert minimal_polynomial(1, x) == x - 1
    assert minimal_polynomial(7, x) == x - 7

    assert minimal_polynomial(sqrt(2), x) == x**2 - 2
    assert minimal_polynomial(sqrt(5), x) == x**2 - 5
    assert minimal_polynomial(sqrt(6), x) == x**2 - 6

    assert minimal_polynomial(2 * sqrt(2), x) == x**2 - 8
    assert minimal_polynomial(3 * sqrt(5), x) == x**2 - 45
    assert minimal_polynomial(4 * sqrt(6), x) == x**2 - 96

    assert minimal_polynomial(2 * sqrt(2) + 3, x) == x**2 - 6 * x + 1
    assert minimal_polynomial(3 * sqrt(5) + 6, x) == x**2 - 12 * x - 9
    assert minimal_polynomial(4 * sqrt(6) + 7, x) == x**2 - 14 * x - 47

    assert minimal_polynomial(2 * sqrt(2) - 3, x) == x**2 + 6 * x + 1
    assert minimal_polynomial(3 * sqrt(5) - 6, x) == x**2 + 12 * x - 9
    assert minimal_polynomial(4 * sqrt(6) - 7, x) == x**2 + 14 * x - 47

    assert minimal_polynomial(sqrt(1 + sqrt(6)), x) == x**4 - 2 * x**2 - 5
    assert minimal_polynomial(sqrt(I + sqrt(6)), x) == x**8 - 10 * x**4 + 49

    assert (minimal_polynomial(2 * I + sqrt(2 + I),
                               x) == x**4 + 4 * x**2 + 8 * x + 37)

    assert minimal_polynomial(sqrt(2) + sqrt(3), x) == x**4 - 10 * x**2 + 1
    assert (minimal_polynomial(sqrt(2) + sqrt(3) + sqrt(6),
                               x) == x**4 - 22 * x**2 - 48 * x - 23)

    a = 1 - 9 * sqrt(2) + 7 * sqrt(3)

    assert (minimal_polynomial(1 / a, x) == 392 * x**4 - 1232 * x**3 +
            612 * x**2 + 4 * x - 1)
    assert (minimal_polynomial(1 / sqrt(a), x) == 392 * x**8 - 1232 * x**6 +
            612 * x**4 + 4 * x**2 - 1)

    raises(NotAlgebraic, lambda: minimal_polynomial(oo, x))
    raises(NotAlgebraic, lambda: minimal_polynomial(2**y, x))
    raises(NotAlgebraic, lambda: minimal_polynomial(sin(1), x))

    assert minimal_polynomial(sqrt(2)).dummy_eq(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x) == x**2 - 2

    assert minimal_polynomial(sqrt(2), polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x, polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(sqrt(2), x, polys=True,
                              compose=False) == Poly(x**2 - 2)

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(3))

    assert minimal_polynomial(a, x) == x**2 - 2
    assert minimal_polynomial(b, x) == x**2 - 3

    assert minimal_polynomial(a, x, polys=True) == Poly(x**2 - 2)
    assert minimal_polynomial(b, x, polys=True) == Poly(x**2 - 3)

    assert minimal_polynomial(sqrt(a / 2 + 17),
                              x) == 2 * x**4 - 68 * x**2 + 577
    assert minimal_polynomial(sqrt(b / 2 + 17),
                              x) == 4 * x**4 - 136 * x**2 + 1153

    a, b = sqrt(2) / 3 + 7, AlgebraicNumber(sqrt(2) / 3 + 7)

    f = (81 * x**8 - 2268 * x**6 - 4536 * x**5 + 22644 * x**4 + 63216 * x**3 -
         31608 * x**2 - 189648 * x + 141358)

    assert minimal_polynomial(sqrt(a) + sqrt(sqrt(a)), x) == f
    assert minimal_polynomial(sqrt(b) + sqrt(sqrt(b)), x) == f

    assert (minimal_polynomial(a**Q(3, 2),
                               x) == 729 * x**4 - 506898 * x**2 + 84604519)

    # issue 5994
    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)))""")
    assert minimal_polynomial(eq, x) == 8000 * x**2 - 1

    ex = 1 + sqrt(2) + sqrt(3)
    mp = minimal_polynomial(ex, x)
    assert mp == x**4 - 4 * x**3 - 4 * x**2 + 16 * x - 8

    ex = 1 / (1 + sqrt(2) + sqrt(3))
    mp = minimal_polynomial(ex, x)
    assert mp == 8 * x**4 - 16 * x**3 + 4 * x**2 + 4 * x - 1

    p = (expand((1 + sqrt(2) - 2 * sqrt(3) + sqrt(7))**3))**Rational(1, 3)
    mp = minimal_polynomial(p, x)
    assert (mp == x**8 - 8 * x**7 - 56 * x**6 + 448 * x**5 + 480 * x**4 -
            5056 * x**3 + 1984 * x**2 + 7424 * x - 3008)
    p = expand((1 + sqrt(2) - 2 * sqrt(3) + sqrt(7))**3)
    mp = minimal_polynomial(p, x)
    assert (mp == x**8 - 512 * x**7 - 118208 * x**6 + 31131136 * x**5 +
            647362560 * x**4 - 56026611712 * x**3 + 116994310144 * x**2 +
            404854931456 * x - 27216576512)

    assert minimal_polynomial(S("-sqrt(5)/2 - 1/2 + (-sqrt(5)/2 - 1/2)**2"),
                              x) == x - 1
    a = 1 + sqrt(2)
    assert minimal_polynomial((a * sqrt(2) + a)**3, x) == x**2 - 198 * x + 1

    p = 1 / (1 + sqrt(2) + sqrt(3))
    assert (minimal_polynomial(p, x, compose=False) == 8 * x**4 - 16 * x**3 +
            4 * x**2 + 4 * x - 1)

    p = 2 / (1 + sqrt(2) + sqrt(3))
    assert (minimal_polynomial(p, x, compose=False) == x**4 - 4 * x**3 +
            2 * x**2 + 4 * x - 2)

    assert minimal_polynomial(1 + sqrt(2) * I, x,
                              compose=False) == x**2 - 2 * x + 3
    assert minimal_polynomial(1 / (1 + sqrt(2)) + 1, x,
                              compose=False) == x**2 - 2
    assert (minimal_polynomial(sqrt(2) * I + I * (1 + sqrt(2)),
                               x,
                               compose=False) == x**4 + 18 * x**2 + 49)

    # minimal polynomial of I
    assert minimal_polynomial(I, x, domain=QQ.algebraic_field(I)) == x - I
    K = QQ.algebraic_field(I * (sqrt(2) + 1))
    assert minimal_polynomial(I, x, domain=K) == x - I
    assert minimal_polynomial(I, x, domain=QQ) == x**2 + 1
    assert minimal_polynomial(I, x, domain="QQ(y)") == x**2 + 1

    # issue 11553
    assert minimal_polynomial(GoldenRatio, x) == x**2 - x - 1
    assert (minimal_polynomial(TribonacciConstant + 3,
                               x) == x**3 - 10 * x**2 + 32 * x - 34)
    assert (minimal_polynomial(GoldenRatio,
                               x,
                               domain=QQ.algebraic_field(sqrt(5))) == 2 * x -
            sqrt(5) - 1)
    assert (minimal_polynomial(TribonacciConstant,
                               x,
                               domain=QQ.algebraic_field(
                                   cbrt(19 - 3 * sqrt(33)))) == 48 * x - 19 *
            (19 - 3 * sqrt(33))**Rational(2, 3) - 3 * sqrt(33) *
            (19 - 3 * sqrt(33))**Rational(2, 3) - 16 *
            (19 - 3 * sqrt(33))**Rational(1, 3) - 16)
Exemple #14
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def test_field_isomorphism():
    assert field_isomorphism(3, sqrt(2)) == [3]

    assert field_isomorphism(I * sqrt(3), I * sqrt(3) / 2) == [2, 0]
    assert field_isomorphism(-I * sqrt(3), I * sqrt(3) / 2) == [-2, 0]

    assert field_isomorphism(I * sqrt(3), -I * sqrt(3) / 2) == [-2, 0]
    assert field_isomorphism(-I * sqrt(3), -I * sqrt(3) / 2) == [2, 0]

    assert field_isomorphism(2 * I * sqrt(3) / 7, 5 * I * sqrt(3) / 3) == [
        Rational(6, 35),
        0,
    ]
    assert field_isomorphism(-2 * I * sqrt(3) / 7, 5 * I * sqrt(3) / 3) == [
        Rational(-6, 35),
        0,
    ]

    assert field_isomorphism(2 * I * sqrt(3) / 7, -5 * I * sqrt(3) / 3) == [
        Rational(-6, 35),
        0,
    ]
    assert field_isomorphism(-2 * I * sqrt(3) / 7, -5 * I * sqrt(3) / 3) == [
        Rational(6, 35),
        0,
    ]

    assert field_isomorphism(2 * I * sqrt(3) / 7 + 27,
                             5 * I * sqrt(3) / 3) == [
                                 Rational(6, 35),
                                 27,
                             ]
    assert field_isomorphism(-2 * I * sqrt(3) / 7 + 27,
                             5 * I * sqrt(3) / 3) == [
                                 Rational(-6, 35),
                                 27,
                             ]

    assert field_isomorphism(2 * I * sqrt(3) / 7 + 27,
                             -5 * I * sqrt(3) / 3) == [
                                 Rational(-6, 35),
                                 27,
                             ]
    assert field_isomorphism(-2 * I * sqrt(3) / 7 + 27,
                             -5 * I * sqrt(3) / 3) == [
                                 Rational(6, 35),
                                 27,
                             ]

    p = AlgebraicNumber(sqrt(2) + sqrt(3))
    q = AlgebraicNumber(-sqrt(2) + sqrt(3))
    r = AlgebraicNumber(sqrt(2) - sqrt(3))
    s = AlgebraicNumber(-sqrt(2) - sqrt(3))

    pos_coeffs = [S.Half, S.Zero, Rational(-9, 2), S.Zero]
    neg_coeffs = [Rational(-1, 2), S.Zero, Rational(9, 2), S.Zero]

    a = AlgebraicNumber(sqrt(2))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == pos_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_coeffs
    assert field_isomorphism(a, s, fast=True) == neg_coeffs

    assert field_isomorphism(a, p, fast=False) == pos_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_coeffs
    assert field_isomorphism(a, s, fast=False) == neg_coeffs

    a = AlgebraicNumber(-sqrt(2))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == neg_coeffs
    assert field_isomorphism(a, q, fast=True) == pos_coeffs
    assert field_isomorphism(a, r, fast=True) == neg_coeffs
    assert field_isomorphism(a, s, fast=True) == pos_coeffs

    assert field_isomorphism(a, p, fast=False) == neg_coeffs
    assert field_isomorphism(a, q, fast=False) == pos_coeffs
    assert field_isomorphism(a, r, fast=False) == neg_coeffs
    assert field_isomorphism(a, s, fast=False) == pos_coeffs

    pos_coeffs = [S.Half, S.Zero, Rational(-11, 2), S.Zero]
    neg_coeffs = [Rational(-1, 2), S.Zero, Rational(11, 2), S.Zero]

    a = AlgebraicNumber(sqrt(3))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == neg_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_coeffs
    assert field_isomorphism(a, s, fast=True) == pos_coeffs

    assert field_isomorphism(a, p, fast=False) == neg_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_coeffs
    assert field_isomorphism(a, s, fast=False) == pos_coeffs

    a = AlgebraicNumber(-sqrt(3))

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == pos_coeffs
    assert field_isomorphism(a, q, fast=True) == pos_coeffs
    assert field_isomorphism(a, r, fast=True) == neg_coeffs
    assert field_isomorphism(a, s, fast=True) == neg_coeffs

    assert field_isomorphism(a, p, fast=False) == pos_coeffs
    assert field_isomorphism(a, q, fast=False) == pos_coeffs
    assert field_isomorphism(a, r, fast=False) == neg_coeffs
    assert field_isomorphism(a, s, fast=False) == neg_coeffs

    pos_coeffs = [Rational(3, 2), S.Zero, Rational(-33, 2), -S(8)]
    neg_coeffs = [Rational(-3, 2), S.Zero, Rational(33, 2), -S(8)]

    a = AlgebraicNumber(3 * sqrt(3) - 8)

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == neg_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_coeffs
    assert field_isomorphism(a, s, fast=True) == pos_coeffs

    assert field_isomorphism(a, p, fast=False) == neg_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_coeffs
    assert field_isomorphism(a, s, fast=False) == pos_coeffs

    a = AlgebraicNumber(3 * sqrt(2) + 2 * sqrt(3) + 1)

    pos_1_coeffs = [S.Half, S.Zero, Rational(-5, 2), S.One]
    neg_5_coeffs = [Rational(-5, 2), S.Zero, Rational(49, 2), S.One]
    pos_5_coeffs = [Rational(5, 2), S.Zero, Rational(-49, 2), S.One]
    neg_1_coeffs = [Rational(-1, 2), S.Zero, Rational(5, 2), S.One]

    assert is_isomorphism_possible(a, p) is True
    assert is_isomorphism_possible(a, q) is True
    assert is_isomorphism_possible(a, r) is True
    assert is_isomorphism_possible(a, s) is True

    assert field_isomorphism(a, p, fast=True) == pos_1_coeffs
    assert field_isomorphism(a, q, fast=True) == neg_5_coeffs
    assert field_isomorphism(a, r, fast=True) == pos_5_coeffs
    assert field_isomorphism(a, s, fast=True) == neg_1_coeffs

    assert field_isomorphism(a, p, fast=False) == pos_1_coeffs
    assert field_isomorphism(a, q, fast=False) == neg_5_coeffs
    assert field_isomorphism(a, r, fast=False) == pos_5_coeffs
    assert field_isomorphism(a, s, fast=False) == neg_1_coeffs

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(3))
    c = AlgebraicNumber(sqrt(7))

    assert is_isomorphism_possible(a, b) is True
    assert is_isomorphism_possible(b, a) is True

    assert is_isomorphism_possible(c, p) is False

    assert field_isomorphism(sqrt(2), sqrt(3), fast=True) is None
    assert field_isomorphism(sqrt(3), sqrt(2), fast=True) is None

    assert field_isomorphism(sqrt(2), sqrt(3), fast=False) is None
    assert field_isomorphism(sqrt(3), sqrt(2), fast=False) is None
Exemple #15
0
def test_AlgebraicNumber():
    minpoly, root = x ** 2 - 2, sqrt(2)

    a = AlgebraicNumber(root, gen=x)

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased == False

    assert a.coeffs() == [S(1), S(0)]
    assert a.native_coeffs() == [QQ(1), QQ(0)]

    a = AlgebraicNumber(root, gen=x, alias="y")

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias == Symbol("y")
    assert a.minpoly == minpoly

    assert a.is_aliased == True

    a = AlgebraicNumber(root, gen=x, alias=Symbol("y"))

    assert a.rep == DMP([QQ(1), QQ(0)], QQ)
    assert a.root == root
    assert a.alias == Symbol("y")
    assert a.minpoly == minpoly

    assert a.is_aliased == True

    assert AlgebraicNumber(sqrt(2), []).rep == DMP([], QQ)

    assert AlgebraicNumber(sqrt(2), [8]).rep == DMP([QQ(8)], QQ)
    assert AlgebraicNumber(sqrt(2), [S(8) / 3]).rep == DMP([QQ(8, 3)], QQ)

    assert AlgebraicNumber(sqrt(2), [7, 3]).rep == DMP([QQ(7), QQ(3)], QQ)
    assert AlgebraicNumber(sqrt(2), [S(7) / 9, S(3) / 2]).rep == DMP([QQ(7, 9), QQ(3, 2)], QQ)

    assert AlgebraicNumber(sqrt(2), [1, 2, 3]).rep == DMP([QQ(2), QQ(5)], QQ)

    a = AlgebraicNumber(AlgebraicNumber(root, gen=x), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased == False

    assert a.coeffs() == [S(1), S(2)]
    assert a.native_coeffs() == [QQ(1), QQ(2)]

    a = AlgebraicNumber((minpoly, root), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased == False

    a = AlgebraicNumber((Poly(minpoly), root), [1, 2])

    assert a.rep == DMP([QQ(1), QQ(2)], QQ)
    assert a.root == root
    assert a.alias is None
    assert a.minpoly == minpoly

    assert a.is_aliased == False

    assert AlgebraicNumber(sqrt(3)).rep == DMP([QQ(1), QQ(0)], QQ)
    assert AlgebraicNumber(-sqrt(3)).rep == DMP([-QQ(1), QQ(0)], QQ)

    a = AlgebraicNumber(sqrt(2))
    b = AlgebraicNumber(sqrt(2))

    assert a == b and a == sqrt(2)

    a = AlgebraicNumber(sqrt(2), gen=x)
    b = AlgebraicNumber(sqrt(2), gen=x)

    assert a == b and a == sqrt(2)

    a = AlgebraicNumber(sqrt(2), [1, 2])
    b = AlgebraicNumber(sqrt(2), [1, 3])

    assert a != b and a != sqrt(2) + 3

    assert (a == x) == False and (a != x) == True

    a = AlgebraicNumber(sqrt(2), [1, 0])
    b = AlgebraicNumber(sqrt(2), [1, 0], alias=y)

    assert a.as_poly(x) == Poly(x)
    assert b.as_poly() == Poly(y)

    assert a.as_expr() == sqrt(2)
    assert a.as_expr(x) == x
    assert b.as_expr() == sqrt(2)
    assert b.as_expr(x) == x

    a = AlgebraicNumber(sqrt(2), [2, 3])
    b = AlgebraicNumber(sqrt(2), [2, 3], alias=y)

    p = a.as_poly()

    assert p == Poly(2 * p.gen + 3)

    assert a.as_poly(x) == Poly(2 * x + 3)
    assert b.as_poly() == Poly(2 * y + 3)

    assert a.as_expr() == 2 * sqrt(2) + 3
    assert a.as_expr(x) == 2 * x + 3
    assert b.as_expr() == 2 * sqrt(2) + 3
    assert b.as_expr(x) == 2 * x + 3