def test_avf(self):
max_order = 5
a = AVF
b = modified_equation(a)
result1 = convergence_order(a)
self.assertEqual(2, result1)
result2 = symplectic_up_to_order(a)
self.assertEqual(2, result2)
result3 = conjugate_to_symplectic(a)
self.assertEqual(4, result3)
result4 = symmetric_up_to_order(a, max_order)
self.assertEqual(max_order, result4)
result5 = energy_preserving_upto_order(b, max_order)
self.assertEqual(max_order, result5) # = energy preserving
def test_RKcashKarp(self):
a = RKcashKarp.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(5, result) # = order
def test_rk38(self):
a = RK38rule.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(4, result) # = order
def test_RKlobattoIIIB4(self):
a = RKlobattoIIIB4.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(4, result) # = order
def test_runge2(self):
a = RKrunge2.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(2, result) # = order
def test_implicit_trapezoidal(self):
a = RKimplicitTrapezoidal.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(2, result) # = order
def test_implicit_midpoint(self):
a = RKimplicitMidpoint.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(2, result) # = order
def test_implicit_euler(self):
a = RKimplicitEuler.phi()
b = modified_equation(a)
result = energy_preserving_upto_order(b)
self.assertEqual(1, result) # = order
def test_exact(self):
max_order = 5
a = exponential
b = modified_equation(a)
result = energy_preserving_upto_order(b, max_order)
self.assertEqual(max_order, result)