def test_logistic_scalar(self):
var = Variable(2, 7)
result = var.logistic()
expected_derivative = (var.derivative * np.exp(-2)) / (1 +
np.exp(-2))**2
self.assertAlmostEqual(1 / (1 + np.exp(-2)), result.value)
self.assertAlmostEqual(expected_derivative, result.derivative)
def test_logistic_vector(self):
var = Variable(2, np.array([2, 6, 8]))
x = Variable(5, np.array([0.5, 0.7]))
y = Variable(3, np.array([0.5, 0.9]))
result = var.logistic()
expected_derivative = (var.derivative * np.exp(-2)) / (1 +
np.exp(-2))**2
equation = x + y**5
equation_result = equation.logistic()
equation_expected_derivative = (equation.derivative *
np.exp(-equation.value)) / (
1 + np.exp(-equation.value))**2
self.assertAlmostEqual(1 / (1 + np.exp(-2)), result.value)
np.testing.assert_array_almost_equal(expected_derivative,
result.derivative)
self.assertAlmostEqual(1 / (1 + np.exp(-equation.value)),
equation_result.value)
np.testing.assert_array_almost_equal(equation_expected_derivative,
equation_result.derivative)
