def testGetDatum_firstOrderTerm(self):
tf = DiscreteTransferFunction([1, 1], [1])
tf.append(1)
self.assertAlmostEqual(tf.get_datum(),
2,
msg="Fails to add a first order term "
"in the numerator")
def testGetDatum_underFilledBuffer(self):
tf = DiscreteTransferFunction(list(reversed(range(10))), [1])
tf.append(1)
tf.append(2)
self.assertAlmostEqual(tf.get_datum(),
4,
msg="Fails to return data using only "
"the lowest order coefficients")
def testGetDatum_nominal(self):
tf = DiscreteTransferFunction([1], [1])
tf.append(0)
self.assertAlmostEqual(tf.get_datum(),
1,
msg="Fails to give the quotient of the "
"constant terms when the "
"numerator and denominator are "
"both length 1")
def testStr_leadingCoefficientsAreConstantTermsAndOne(self):
tf = DiscreteTransferFunction([1], [1])
self.assertEqual(
str(tf), "1\n"
"-\n"
"1", "Fails to properly format a transfer function "
"where the leading term is both constant "
"and the coefficient is equal to 1")
def testStr_leadingCoefficientOtherThanOne(self):
tf = DiscreteTransferFunction([2, -2], [1, -0.8])
self.assertEqual(
str(tf), "2 z - 2\n"
"--------\n"
" z - 0.8", "Fails to properly format a transfer function "
"that has a leading coefficient other than "
"one")
def testStr_nominal(self):
tf = DiscreteTransferFunction([1, -1], [1, -1.85, 0.9])
self.assertEqual(
str(tf), " z - 1\n"
"-------------------\n"
" z^2 - 1.85 z + 0.9",
"Fails to represent a transfer function as a "
"pretty string.")
def testAppend_manyData(self):
tf = DiscreteTransferFunction([1, 1, 1, 1, 1], [1])
tf.append(0)
tf.append(1)
tf.append(2)
tf.append(3)
tf.append(4)
self.assertTrue(
tf.is_full, "Fails to append many data to the transfer "
"function")
def testGetDatum_fibonacci(self):
tf = DiscreteTransferFunction([1, 1, 0], [1])
fibonacciNumbers = [1, 1]
tf.append(1)
tf.append(1)
for _ in range(4):
fibonacciNumbers.append(tf.get_datum())
tf.append(tf.get_datum())
desiredList = [1, 1, 2, 3, 5, 8]
self.assertTrue(
all(
math.isclose(actual, desired)
for (actual, desired) in zip(fibonacciNumbers, desiredList)),
"Fails to generate a sequence of numbers "
"with the numerator having non-constant "
"terms\n"
" " + str(desiredList) + "\n"
"!= " + str(fibonacciNumbers))
def testGetDatum_regularAndInverseFibonacci(self):
tf = DiscreteTransferFunction([1, 1, 0], [1, 1, 0])
regularAndInverseFibonacciNumbers = [1, 1]
tf.append(1)
tf.append(1)
for _ in range(4):
regularAndInverseFibonacciNumbers.append(tf.get_datum())
tf.append(tf.get_datum())
desiredList = [1, 1, 1, 1, 1, 1]
self.assertTrue(
all(
math.isclose(actual, desired)
for (actual, desired
) in zip(regularAndInverseFibonacciNumbers, desiredList)),
"Fails to generate a sequence of numbers with "
"the numerator and denominator having "
"non-constant terms\n"
" " + str(desiredList) + "\n"
"!= " + str(regularAndInverseFibonacciNumbers))
def testGetDatum_inverseFibonacci(self):
"""invereFibonacci(n) =
1 / (inverseFibonacci(n-1) + inverseFibonacci(n-2))
"""
tf = DiscreteTransferFunction([1], [1, 1, 0])
inverseFibonacciNumbers = [1, 1]
tf.append(1)
tf.append(1)
for _ in range(4):
inverseFibonacciNumbers.append(tf.get_datum())
tf.append(tf.get_datum())
desiredList = [1, 1, 1 / 2, 2 / 3, 6 / 7, 21 / 32]
self.assertTrue(
all(
math.isclose(actual, desired)
for (actual,
desired) in zip(inverseFibonacciNumbers, desiredList)),
"Fails to generate a sequence of numbers with "
"the denominator having non-constant terms\n"
" " + str(desiredList) + "\n"
"!= " + str(inverseFibonacciNumbers))
def testInit_nominal(self):
tf = DiscreteTransferFunction([1], [1])
self.assertIsNotNone(
tf, "Fails to initialize a discrete "
"transfer function")
def testAppend_nominal(self):
tf = DiscreteTransferFunction([1, 1], [1])
tf.append(0)
self.assertTrue(
tf.is_full, "Fails to append a datum to the transfer "
"function's buffer")
def testInit_divideByZeroMany(self):
with self.assertRaises(ZeroDivisionError,
msg="Fails to raise an exception when the "
"denominator equals zero."):
DiscreteTransferFunction([1], [0] * 50)