def test_cost_stddev():
x = np.array([-100.0, 100.0])
assert af.cost_stddev(x) == 1.0
def test_cost_stddev_range():
image = np.random.randn(100).reshape(10, 10)
r = af.cost_stddev(image)
assert r >= 0.0 and r <= 1.0
def test_cost_stddev():
x = np.array([-100.0, 100.0])
assert af.cost_stddev(x) == 1.0
def test_cost_stddev_range():
image = np.random.randn(100).reshape(10, 10)
r = af.cost_stddev(image)
assert r >= 0.0 and r <= 1.0