def is_pell_transformation_ok(eq):
"""
Test whether X*Y, X, or Y terms are present in the equation
after transforming the equation using the transformation returned
by transformation_to_pell(). If they are not present we are good.
Moreover, coefficient of X**2 should be a divisor of coefficient of
Y**2 and the constant term.
"""
A, B = transformation_to_DN(eq)
u = (A * Matrix([X, Y]) + B)[0]
v = (A * Matrix([X, Y]) + B)[1]
simplified = diop_simplify(eq.subs({x: u, y: v}))
coeff = {
val: key
for key, val in (t.as_independent(X, Y) for t in simplified.args)
}
for term in [X * Y, X, Y]:
if term in coeff:
return False
for term in [X**2, Y**2, Integer(1)]:
if term not in coeff:
coeff[term] = Integer(0)
if coeff[X**2] != 0:
return isinstance(coeff[Y**2] / coeff[X**2], Integer) and isinstance(
coeff[Integer(1)] / coeff[X**2], Integer)
return True
def is_pell_transformation_ok(eq):
"""
Test whether X*Y, X, or Y terms are present in the equation
after transforming the equation using the transformation returned
by transformation_to_pell(). If they are not present we are good.
Moreover, coefficient of X**2 should be a divisor of coefficient of
Y**2 and the constant term.
"""
A, B = transformation_to_DN(eq)
u = (A*Matrix([X, Y]) + B)[0]
v = (A*Matrix([X, Y]) + B)[1]
simplified = _mexpand(Subs(eq, (x, y), (u, v)).doit())
coeff = dict(reversed(t.as_independent(*[X, Y])) for t in simplified.args)
for term in [X*Y, X, Y]:
if term in coeff.keys():
return False
for term in [X**2, Y**2, Integer(1)]:
if term not in coeff.keys():
coeff[term] = Integer(0)
if coeff[X**2] != 0:
return isinstance(coeff[Y**2]/coeff[X**2], Integer) and isinstance(coeff[Integer(1)]/coeff[X**2], Integer)
return True
def is_pell_transformation_ok(eq):
"""
Test whether X*Y, X, or Y terms are present in the equation
after transforming the equation using the transformation returned
by transformation_to_pell(). If they are not present we are good.
Moreover, coefficient of X**2 should be a divisor of coefficient of
Y**2 and the constant term.
"""
A, B = transformation_to_DN(eq)
u = (A*Matrix([X, Y]) + B)[0]
v = (A*Matrix([X, Y]) + B)[1]
simplified = diop_simplify(eq.subs({x: u, y: v}))
coeff = {val: key for key, val in (t.as_independent(X, Y)
for t in simplified.args)}
for term in [X*Y, X, Y]:
if term in coeff:
return False
for term in [X**2, Y**2, Integer(1)]:
if term not in coeff:
coeff[term] = Integer(0)
if coeff[X**2] != 0:
return isinstance(coeff[Y**2]/coeff[X**2], Integer) and isinstance(coeff[Integer(1)]/coeff[X**2], Integer)
return True
def test_diopcoverage():
eq = (2*x + y + 1)**2
assert diop_solve(eq) == {(t_0, -2*t_0 - 1)}
eq = 2*x**2 + 6*x*y + 12*x + 4*y**2 + 18*y + 18
assert diop_solve(eq) == {(t_0, -t_0 - 3), (2*t_0 - 3, -t_0)}
assert diop_quadratic(x + y**2 - 3) == {(-t**2 + 3, -t)}
assert diop_quadratic(x + y) is None # wrong type
assert diop_linear(x + y - 3) == (t_0, 3 - t_0)
assert diop_linear(x**2 - 1) is None # wrong type
assert base_solution_linear(0, 1, 2, t=None) == (0, 0)
ans = (3*t - 1, -2*t + 1)
assert base_solution_linear(4, 8, 12, t) == ans
assert base_solution_linear(4, 8, 12, t=None) == tuple(_.subs({t: 0}) for _ in ans)
assert cornacchia(1, 1, 20) is None
assert cornacchia(1, 1, 5) == {(1, 2)}
assert cornacchia(1, 2, 17) == {(3, 2)}
assert cornacchia(2, 3, 31) == set()
pytest.raises(ValueError, lambda: reconstruct(4, 20, 1))
assert gaussian_reduce(4, 1, 3) == (1, 1)
eq = -w**2 - x**2 - y**2 + z**2
assert (diop_general_pythagorean(eq) == diop_general_pythagorean(-eq) ==
(m1**2 + m2**2 - m3**2, 2*m1*m3, 2*m2*m3, m1**2 + m2**2 + m3**2))
assert check_param(Integer(3) + x/3, Integer(4) + x/2,
Integer(2), x) == (None, None)
assert check_param(Rational(3, 2), Integer(4) + x,
Integer(2), x) == (None, None)
assert check_param(Integer(4) + x, Rational(3, 2),
Integer(2), x) == (None, None)
assert _nint_or_floor(16, 10) == 2
assert _odd(1) == (not _even(1)) is True
assert _odd(0) == (not _even(0)) is False
assert _remove_gcd(2, 4, 6) == (1, 2, 3)
pytest.raises(TypeError, lambda: _remove_gcd((2, 4, 6)))
assert sqf_normal(2 * 3**2 * 5, 2 * 5 * 11, 2 * 7**2 * 11) == (11, 1, 5)
# it's ok if these pass some day when the solvers are implemented
pytest.raises(NotImplementedError, lambda: diophantine(x**2 + y**2 + x*y + 2*y*z - 12))
pytest.raises(NotImplementedError, lambda: diophantine(x**3 + y**2))
# issue sympy/sympy#11026
pytest.raises(NotImplementedError, lambda: diophantine(x**3 + y**3 - 2))
assert transformation_to_DN(x + y) is None # wrong type
assert find_DN(x + y) is None # wrong type
assert diop_ternary_quadratic(x + y) is None # wrong type
assert transformation_to_normal(x + y) is None # wrong type
assert parametrize_ternary_quadratic(x + y) is None # wrong type
assert diop_general_pythagorean(x + y) is None # wrong type
assert diop_general_sum_of_squares(x + y) is None # wrong type
assert diop_general_sum_of_even_powers(x + y) is None # wrong type
def test_diopcoverage():
eq = (2 * x + y + 1)**2
assert diop_solve(eq) == {(t_0, -2 * t_0 - 1)}
eq = 2 * x**2 + 6 * x * y + 12 * x + 4 * y**2 + 18 * y + 18
assert diop_solve(eq) == {(t_0, -t_0 - 3), (2 * t_0 - 3, -t_0)}
assert diop_quadratic(x + y**2 - 3) == {(-t**2 + 3, -t)}
assert diop_quadratic(x + y) is None # wrong type
assert diop_linear(x + y - 3) == (t_0, 3 - t_0)
assert diop_linear(x**2 - 1) is None # wrong type
assert base_solution_linear(0, 1, 2, t=None) == (0, 0)
ans = (3 * t - 1, -2 * t + 1)
assert base_solution_linear(4, 8, 12, t) == ans
assert base_solution_linear(4, 8, 12,
t=None) == tuple(_.subs({t: 0}) for _ in ans)
assert cornacchia(1, 1, 20) is None
assert cornacchia(1, 1, 5) == {(2, 1)}
assert cornacchia(1, 2, 17) == {(3, 2)}
assert cornacchia(2, 3, 31) == set()
assert cornacchia(1, 4, 52) == {(4, 3)}
pytest.raises(ValueError, lambda: reconstruct(4, 20, 1))
assert gaussian_reduce(4, 1, 3) == (1, 1)
eq = -w**2 - x**2 - y**2 + z**2
assert (diop_general_pythagorean(eq) == diop_general_pythagorean(-eq) ==
(m1**2 + m2**2 - m3**2, 2 * m1 * m3, 2 * m2 * m3,
m1**2 + m2**2 + m3**2))
assert check_param(Integer(3) + x / 3,
Integer(4) + x / 2, Integer(2), x) == (None, None)
assert check_param(Rational(3, 2),
Integer(4) + x, Integer(2), x) == (None, None)
assert check_param(Integer(4) + x, Rational(3, 2), Integer(2),
x) == (None, None)
assert _nint_or_floor(16, 10) == 2
assert _odd(1) == (not _even(1)) is True
assert _odd(0) == (not _even(0)) is False
assert _remove_gcd(2, 4, 6) == (1, 2, 3)
assert sqf_normal(2 * 3**2 * 5, 2 * 5 * 11, 2 * 7**2 * 11) == (11, 1, 5)
# it's ok if these pass some day when the solvers are implemented
pytest.raises(NotImplementedError,
lambda: diophantine(x**2 + y**2 + x * y + 2 * y * z - 12))
pytest.raises(NotImplementedError, lambda: diophantine(x**3 + y**2))
# issue sympy/sympy#11026
pytest.raises(NotImplementedError, lambda: diophantine(x**3 + y**3 - 2))
assert transformation_to_DN(x + y) is None # wrong type
assert find_DN(x + y) is None # wrong type
assert diop_ternary_quadratic(x + y) is None # wrong type
assert transformation_to_normal(x + y) is None # wrong type
assert parametrize_ternary_quadratic(x + y) is None # wrong type
assert diop_general_pythagorean(x + y) is None # wrong type
assert diop_general_sum_of_squares(x + y) is None # wrong type
assert diop_general_sum_of_even_powers(x + y) is None # wrong type
assert diop_quadratic(x**2 + y**2 - 1**2 - 3**4) == \
{(-9, -1), (-9, 1), (-1, -9), (-1, 9), (1, -9), (1, 9), (9, -1), (9, 1)}