def setUp(self):
self.bias = Function('bias')
self.identity = Function('identity')
self.degree = 2 # polynomial degree
self.poly = Function('polynomial', degree=self.degree)
self.poly_derivative = self.poly.derivative()
self.mu = 3
self.std_dev = 4
self.standard_gaussian = Function('gaussian')
self.gaussian = Function('gaussian', mu=self.mu,
sigma=self.std_dev)
self.gaussian_derivative = self.gaussian.derivative()
self.logistic_sigmoid = Function('sigmoid', mu=self.mu,
sigma=self.std_dev,
sig_func='logistic')
self.logistic_sigmoid_derivative = self.logistic_sigmoid.derivative()
self.tanh_sigmoid = Function('sigmoid', mu=self.mu,
sigma=self.std_dev,
sig_func='tanh')
self.tanh_sigmoid_derivative = self.tanh_sigmoid.derivative()
self.test_points = range(10)
def test_custom_function(self):
""" Define a custom sin function, which is the unique solution to
f'' = -f, f(0) = 0, f'(0) = 1
"""
f = Function(func_type="sin", func=lambda j: math.sin(j))
f_prime = f.derivative()
f_prime_prime = f.derivative().derivative()
self.assertEqual(str(f), "Sin function")
self.assertEqual(f(0), 0)
self.assertAlmostEqual(f_prime(0), 1, places=4)
for x in self.test_points:
self.assertAlmostEqual(f(x), -f_prime_prime(x), places=4)
def test_prints(self):
""" Tests the __repr__ functions
"""
self.assertEqual(str(self.logistic_sigmoid), "Sigmoid function")
self.assertEqual(str(Function(func=lambda j: j)), "Custom function")
def test_undefined_sigmoid(self):
self.assertRaises(NotImplementedError,
lambda x: Function("sigmoid", sig_func=x),
"foo")
