"""Tests for the subfield problem and allied problems. """ from sympy.core.numbers import (AlgebraicNumber, I, pi, Rational) from sympy.core.singleton import S from sympy.functions.elementary.exponential import exp from sympy.functions.elementary.miscellaneous import sqrt from sympy.polys.numberfields.subfield import ( is_isomorphism_possible, field_isomorphism_pslq, field_isomorphism, primitive_element, to_number_field, ) from sympy.polys.polyerrors import IsomorphismFailed from sympy.polys.polytools import Poly from sympy.polys.rootoftools import CRootOf from sympy.testing.pytest import raises from sympy.abc import x Q = Rational 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] 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 a = AlgebraicNumber(sqrt(2)) b = AlgebraicNumber(2 ** (S(1) / 3)) assert is_isomorphism_possible(a, b) is False assert field_isomorphism(a, b) is None def test_primitive_element(): assert primitive_element([sqrt(2)], x) == (x**2 - 2, [1]) assert primitive_element( [sqrt(2), sqrt(3)], x) == (x**4 - 10*x**2 + 1, [1, 1]) assert primitive_element([sqrt(2)], x, polys=True) == (Poly(x**2 - 2, domain='QQ'), [1]) assert primitive_element([sqrt( 2), sqrt(3)], x, polys=True) == (Poly(x**4 - 10*x**2 + 1, domain='QQ'), [1, 1]) assert primitive_element( [sqrt(2)], x, ex=True) == (x**2 - 2, [1], [[1, 0]]) assert primitive_element([sqrt(2), sqrt(3)], x, ex=True) == \ (x**4 - 10*x**2 + 1, [1, 1], [[Q(1, 2), 0, -Q(9, 2), 0], [- Q(1, 2), 0, Q(11, 2), 0]]) assert primitive_element( [sqrt(2)], x, ex=True, polys=True) == (Poly(x**2 - 2, domain='QQ'), [1], [[1, 0]]) assert primitive_element([sqrt(2), sqrt(3)], x, ex=True, polys=True) == \ (Poly(x**4 - 10*x**2 + 1, domain='QQ'), [1, 1], [[Q(1, 2), 0, -Q(9, 2), 0], [-Q(1, 2), 0, Q(11, 2), 0]]) assert primitive_element([sqrt(2)], polys=True) == (Poly(x**2 - 2), [1]) raises(ValueError, lambda: primitive_element([], x, ex=False)) raises(ValueError, lambda: primitive_element([], x, ex=True)) # Issue 14117 a, b = I*sqrt(2*sqrt(2) + 3), I*sqrt(-2*sqrt(2) + 3) assert primitive_element([a, b, I], x) == (x**4 + 6*x**2 + 1, [1, 0, 0]) 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))) def test_issue_22561(): a = to_number_field(sqrt(2), sqrt(2) + sqrt(3)) b = to_number_field(sqrt(2), sqrt(2) + sqrt(5)) assert field_isomorphism(a, b) == [1, 0] def test_issue_22736(): a = CRootOf(x**4 + x**3 + x**2 + x + 1, -1) a._reset() b = exp(2*I*pi/5) assert field_isomorphism(a, b) == [1, 0]