def test_non_monic_polynomial(self):
# Testing case where the given polynomial is
# 4x^3 + 2x^2 + x + 1
from CompanionMatrix import create_companion_matrix
coeffs = np.array((4, 2, 1, 1))
test_mat = create_companion_matrix(coeffs)
true_mat = np.array([[0, 0, -0.25], [1, 0, -0.25], [0, 1, -0.5]])
np.testing.assert_array_almost_equal(test_mat, true_mat)
def test_odd_leading_coefficient(self):
# Testing case where the given polynomial is
# x^3 + 3x^2 + 4x + 5
from CompanionMatrix import create_companion_matrix
coeffs = np.array((1, 3, 4, 5))
test_mat = create_companion_matrix(coeffs)
true_mat = np.array([[0, 0, -5], [1, 0, -4], [0, 1, -3]])
np.testing.assert_array_equal(test_mat, true_mat)
def test_zero_constant_term(self):
# Testing case where the given polynomial is
# x^2 + x + 0
from CompanionMatrix import create_companion_matrix
coeffs = np.array((1, 1, 0))
test_mat = create_companion_matrix(coeffs)
true_mat = np.array([[0, 0], [1, -1]])
np.testing.assert_array_equal(test_mat, true_mat)
def test_leading_coefficient_zero(self):
# Testing case where the given polynomial is
# 0x^2 + x + 1
from CompanionMatrix import create_companion_matrix
coeffs = np.array((0, 1, 1))
test_mat = create_companion_matrix(coeffs)
true_mat = np.array([[-1]])
np.testing.assert_array_equal(test_mat, true_mat)
def test_one_zero_coefficient(self):
# Testing case where the given polynomial is
# x^2 + 0x + 1
from CompanionMatrix import create_companion_matrix
coeffs = np.array((1, 0, 1))
test_mat = create_companion_matrix(coeffs)
true_mat = np.array([[0, -1], [1, 0]])
np.testing.assert_array_equal(test_mat, true_mat)
def test_even_leading_coefficient(self):
# Testing case where the given polynomial is
# x^4 + 5x^3 + 4x^2 + 2x + 1
from CompanionMatrix import create_companion_matrix
coeffs = np.array((1, 5, 4, 2, 1))
test_mat = create_companion_matrix(coeffs)
true_mat = np.array([[0, 0, 0, -1], [1, 0, 0, -2], [0, 1, 0, -4],
[0, 0, 1, -5]])
np.testing.assert_array_equal(test_mat, true_mat)