def test_macaulay_example_two():
"""Tests the Macaulay formulation for example from [Stiller96]_."""
x, y, z = symbols('x, y, z')
a_0, a_1, a_2 = symbols('a_0, a_1, a_2')
b_0, b_1, b_2 = symbols('b_0, b_1, b_2')
c_0, c_1, c_2, c_3, c_4 = symbols('c_0, c_1, c_2, c_3, c_4')
f = a_0 * y - a_1 * x + a_2 * z
g = b_1 * x ** 2 + b_0 * y ** 2 - b_2 * z ** 2
h = c_0 * y - c_1 * x ** 3 + c_2 * x ** 2 * z - c_3 * x * z ** 2 + \
c_4 * z ** 3
mac = MacaulayResultant([f, g, h], [x, y, z])
assert mac.degrees == [1, 2, 3]
assert mac.degree_m == 4
assert mac.monomials_size == 15
assert len(mac.get_row_coefficients()) == mac.n
matrix = mac.get_matrix()
assert matrix.shape == (mac.monomials_size, mac.monomials_size)
assert mac.get_submatrix(matrix) == Matrix([[-a_1, a_0, a_2, 0],
[0, -a_1, 0, 0],
[0, 0, -a_1, 0],
[0, 0, 0, -a_1]])
def test_macaulay_example_one():
"""Tests the Macaulay for example from [Bruce97]_"""
x, y, z = symbols('x, y, z')
a_1_1, a_1_2, a_1_3 = symbols('a_1_1, a_1_2, a_1_3')
a_2_2, a_2_3, a_3_3 = symbols('a_2_2, a_2_3, a_3_3')
b_1_1, b_1_2, b_1_3 = symbols('b_1_1, b_1_2, b_1_3')
b_2_2, b_2_3, b_3_3 = symbols('b_2_2, b_2_3, b_3_3')
c_1, c_2, c_3 = symbols('c_1, c_2, c_3')
f_1 = a_1_1 * x ** 2 + a_1_2 * x * y + a_1_3 * x * z + \
a_2_2 * y ** 2 + a_2_3 * y * z + a_3_3 * z ** 2
f_2 = b_1_1 * x ** 2 + b_1_2 * x * y + b_1_3 * x * z + \
b_2_2 * y ** 2 + b_2_3 * y * z + b_3_3 * z ** 2
f_3 = c_1 * x + c_2 * y + c_3 * z
mac = MacaulayResultant([f_1, f_2, f_3], [x, y, z])
assert mac.degrees == [2, 2, 1]
assert mac.degree_m == 3
assert mac.monomial_set == [x ** 3, x ** 2 * y, x ** 2 * z,
x * y ** 2,
x * y * z, x * z ** 2, y ** 3,
y ** 2 *z, y * z ** 2, z ** 3]
assert mac.monomials_size == 10
assert mac.get_row_coefficients() == [[x, y, z], [x, y, z],
[x * y, x * z, y * z, z ** 2]]
matrix = mac.get_matrix()
assert matrix.shape == (mac.monomials_size, mac.monomials_size)
assert mac.get_submatrix(matrix) == Matrix([[a_1_1, a_2_2],
[b_1_1, b_2_2]])
def test_macaulay_example_one():
"""Tests the Macaulay for example from [Bruce97]_"""
x, y, z = symbols('x, y, z')
a_1_1, a_1_2, a_1_3 = symbols('a_1_1, a_1_2, a_1_3')
a_2_2, a_2_3, a_3_3 = symbols('a_2_2, a_2_3, a_3_3')
b_1_1, b_1_2, b_1_3 = symbols('b_1_1, b_1_2, b_1_3')
b_2_2, b_2_3, b_3_3 = symbols('b_2_2, b_2_3, b_3_3')
c_1, c_2, c_3 = symbols('c_1, c_2, c_3')
f_1 = a_1_1 * x ** 2 + a_1_2 * x * y + a_1_3 * x * z + \
a_2_2 * y ** 2 + a_2_3 * y * z + a_3_3 * z ** 2
f_2 = b_1_1 * x ** 2 + b_1_2 * x * y + b_1_3 * x * z + \
b_2_2 * y ** 2 + b_2_3 * y * z + b_3_3 * z ** 2
f_3 = c_1 * x + c_2 * y + c_3 * z
mac = MacaulayResultant([f_1, f_2, f_3], [x, y, z])
assert mac.degrees == [2, 2, 1]
assert mac.degree_m == 3
assert mac.monomial_set == [x ** 3, x ** 2 * y, x ** 2 * z,
x * y ** 2,
x * y * z, x * z ** 2, y ** 3,
y ** 2 *z, y * z ** 2, z ** 3]
assert mac.monomials_size == 10
assert mac.get_row_coefficients() == [[x, y, z], [x, y, z],
[x * y, x * z, y * z, z ** 2]]
matrix = mac.get_matrix()
assert matrix.shape == (mac.monomials_size, mac.monomials_size)
assert mac.get_submatrix(matrix) == Matrix([[a_1_1, a_2_2],
[b_1_1, b_2_2]])
def test_macaulay_example_two():
"""Tests the Macaulay formulation for example from [Stiller96]_."""
x, y, z = symbols('x, y, z')
a_0, a_1, a_2 = symbols('a_0, a_1, a_2')
b_0, b_1, b_2 = symbols('b_0, b_1, b_2')
c_0, c_1, c_2, c_3, c_4 = symbols('c_0, c_1, c_2, c_3, c_4')
f = a_0 * y - a_1 * x + a_2 * z
g = b_1 * x ** 2 + b_0 * y ** 2 - b_2 * z ** 2
h = c_0 * y - c_1 * x ** 3 + c_2 * x ** 2 * z - c_3 * x * z ** 2 + \
c_4 * z ** 3
mac = MacaulayResultant([f, g, h], [x, y, z])
assert mac.degrees == [1, 2, 3]
assert mac.degree_m == 4
assert mac.monomials_size == 15
assert len(mac.get_row_coefficients()) == mac.n
matrix = mac.get_matrix()
assert matrix.shape == (mac.monomials_size, mac.monomials_size)
assert mac.get_submatrix(matrix) == Matrix([[-a_1, a_0, a_2, 0],
[0, -a_1, 0, 0],
[0, 0, -a_1, 0],
[0, 0, 0, -a_1]])
from sympy import Matrix
from sympy.core import symbols
from sympy.tensor.indexed import IndexedBase
from sympy.polys.multivariate_resultants import (DixonResultant,
MacaulayResultant)
c, d = symbols("a, b")
x, y = symbols("x, y")
p = c * x + y
q = x + d * y
dixon = DixonResultant(polynomials=[p, q], variables=[x, y])
macaulay = MacaulayResultant(polynomials=[p, q], variables=[x, y])
def test_dixon_resultant_init():
"""Test init method of DixonResultant."""
a = IndexedBase("alpha")
assert dixon.polynomials == [p, q]
assert dixon.variables == [x, y]
assert dixon.n == 2
assert dixon.m == 2
assert dixon.dummy_variables == [a[0], a[1]]
def test_get_dixon_polynomial_numerical():
"""Test Dixon's polynomial for a numerical example."""
a = IndexedBase("alpha")
