def test_pterm_equalityfalse(self):
"""Test that pterm equality checking fails when it should."""
p1 = func.PolynomialTerm((3, 7))
p2 = func.PolynomialTerm((3, 8))
p3 = func.PolynomialTerm((4, 7))
p4 = func.PolynomialTerm((4, 8))
self.assertNotEqual(p1, p2)
self.assertNotEqual(p1, p3)
self.assertNotEqual(p1, p4)
def d_dx(f):
"""Diferentiate a Pterm, f with respect to it's input variable, x."""
assert isinstance(f,
func.PolynomialTerm), "Input must be of type func.Pterm."
# Grab current terms.
c_old, p_old = f.c, f.p
# Calculate new terms.
p_new = p_old - 1 if p_old != 0 else 0
c_new = c_old * p_old
# Construct a new func.Pterm object.
return func.PolynomialTerm((p_new, c_new))
def test_pterm_zero(self):
"""Test the construction of a zero-th order polynomial term."""
pt_zero = func.PolynomialTerm((0, 3))
self.assertEqual(pt_zero(0), 3)
self.assertEqual(pt_zero(1), 3)
self.assertEqual(pt_zero(-1), 3)
def test_pterm_equalitytrue(self):
"""Test that pterm equality checking succeeds when it should."""
p1 = func.PolynomialTerm((2, -5))
p2 = func.PolynomialTerm((2, -5))
self.assertEqual(p1, p2)
def test_pterm_first(self):
"""Test the construction of a first-order polynomial term."""
pt_first = func.PolynomialTerm((1, 7.5))
self.assertEqual(pt_first(0), 0)
self.assertEqual(pt_first(1), 7.5)
self.assertEqual(pt_first(-1), -7.5)
def test_ddx_basic(self):
"""Test the proper behavior of differentiation for a basic case."""
f_x = func.PolynomialTerm((4, 5))
df_dx = func.PolynomialTerm((3, 20))
self.assertEqual(d_dx(f_x), df_dx)
def test_ddx_const(self):
"""Test that the d_dx function returns a Pterm that is equal to 0*x^0 when
operating on a Pterm equal to c*x^0."""
f_const = func.PolynomialTerm((0, 11))
df_const_dx = func.PolynomialTerm((0, 0))
self.assertEqual(d_dx(f_const), df_const_dx)