def test_evaluateDerivativeOnVectors(self):
sigmoid = Sigmoid()
vector = num.array([1, 2, 3])
num.testing.assert_array_equal(sigmoid.derivative(vector),
num.array([0, -2, -6]))
def test_evaluateDerivativeOnNumbers(self):
sigmoid = Sigmoid()
self.assertEqual(sigmoid.derivative(2), 2 * (1 - 2))