def _zero_second_column(self):
if self._mat[1, 1] == 0 or self._mat[2, 1] % self._mat[1, 1] == 0:
self._second_exact_division()
if self._mat[2, 1] < 0:
self.flip_sign_row(2)
r, s, t = extended_gcd(self._mat[1, 1], self._mat[2, 1])
self._set_zero(1, 2, self._mat[1, 1], self._mat[2, 1], r, s, t)
def _test_extended_gcd_n_times(self, n):
for i in range(n):
aa, bb = numpy.random.randint(10, size=2) + 1
r, s, t = extended_gcd(aa, bb)
# print("%d = %d * (%d) + %d * (%d)" %
# (r, aa, s, bb, t))
wanted = aa * s + bb * t
self.assertEqual(r, wanted)
def test_set_zero(self):
mat = IntMat3x3([3, 4, 5, 0, 1, 2, 6, 7, 8])
ori_mat = copy.copy(mat)
r, s, t = extended_gcd(mat.mat[0, 0], mat.mat[2, 0])
mat._set_zero(0, 2, mat.mat[0, 0], mat.mat[2, 0], r, s, t)
wanted_mat = numpy.array([3, 4, 5, 0, 1, 2, 0, -1, -2]).reshape((3, 3))
wanted_op = numpy.array([1, 0, 0, 0, 1, 0, -2, 0, 1]).reshape((3, 3))
numpy.testing.assert_almost_equal(mat.mat, wanted_mat)
numpy.testing.assert_almost_equal(mat.opL, wanted_op)
# make sure operation is right, which can restore origin matrix
wanted = mat.mat
got = numpy.matmul(mat.opL, numpy.matmul(ori_mat.mat, mat.opR))
numpy.testing.assert_almost_equal(got, wanted)
def _zero_first_ele_in_row_i(self, i):
if self._mat[i, 0] < 0:
self.flip_sign_row(i)
r, s, t = extended_gcd(self._mat[0, 0], self._mat[i, 0])
self._set_zero(0, i, self._mat[0, 0], self._mat[i, 0], r, s, t)