def test_real(self):
"""Test that the procedure works for real numbers."""
for _ in range(self.num_test_repetitions):
v = numpy.random.randn(2)
G_left = givens_matrix_elements(v[0], v[1], which='left')
G_right = givens_matrix_elements(v[0], v[1], which='right')
self.assertAlmostEqual(G_left.dot(v)[0], 0.)
self.assertAlmostEqual(G_right.dot(v)[1], 0.)
def test_already_zero(self):
"""Test when some entries are already zero."""
# Test when left entry is zero
v = numpy.array([0., numpy.random.randn()])
G = givens_matrix_elements(v[0], v[1])
self.assertAlmostEqual(G.dot(v)[0], 0.)
# Test when right entry is zero
v = numpy.array([numpy.random.randn(), 0.])
G = givens_matrix_elements(v[0], v[1])
self.assertAlmostEqual(G.dot(v)[0], 0.)
def test_bad_input(self):
"""Test bad input."""
A = numpy.random.randn(3, 3)
v = numpy.random.randn(2)
G = givens_matrix_elements(v[0], v[1])
with self.assertRaises(ValueError):
double_givens_rotate(A, G, 0, 1, which='a')
def test_odd_dimension(self):
"""Test that it raises an error for odd-dimensional input."""
A = numpy.random.randn(3, 3)
v = numpy.random.randn(2)
G = givens_matrix_elements(v[0], v[1])
with self.assertRaises(ValueError):
double_givens_rotate(A, G, 0, 1, which='row')
with self.assertRaises(ValueError):
double_givens_rotate(A, G, 0, 1, which='col')
def test_bad_input(self):
"""Test bad input."""
with self.assertRaises(ValueError):
v = numpy.random.randn(2)
G = givens_matrix_elements(v[0], v[1], which='a')