def test_standard_array(self):
xn = -1 * np.ones(500)
yn = np.zeros(500)
ynp1 = iters.euler_step(1, xn, yn)
for i in ynp1:
if i != -1:
incorrect = 1
else:
incorrect = 0
self.assertFalse(
incorrect,
'output array is predetermined to all be -1, and they are not')
def test_mult_steps(self):
xn = -9.81
yn = 0
tn = 0
tf = 10
tStep = .005
while tn < 10:
ynp1 = iters.euler_step(tStep, xn, yn)
tn += tStep
yn = ynp1
self.assertTrue((
abs(yn - (-98.1)) < 10**-3
), 'error should be relatively low for many iterations with a small tStep'
)
def test_neg_tStep(self):
self.assertEqual(iters.euler_step(-1, -9.81, 0), 'tStep is < 0',
'tStep must be larger than 0')
def test_heck(self):
self.assertEqual(
iters.euler_step([1, 2, 5j], [51j + 12, 124324.12, 12j + 12j],
[None]), 'tStep is not a scalar')
def test_tStep_list(self):
self.assertEqual(iters.euler_step([1, 2, 5], 1, 1),
'tStep is not a scalar')
def test_tStep_imaginary(self):
self.assertEqual(iters.euler_step(5j, 0, 0), 'tStep is not real')
def test_yn_imaginary(self):
self.assertEqual(iters.euler_step(.001, 0, [5j]),
'yn cannot have any imaginary numbers')
def test_xn_imaginary(self):
self.assertEqual(iters.euler_step(.001, [5j], 0),
'xn cannot have any imaginary numbers')
def test_yn_none(self):
self.assertEqual(iters.euler_step(.001, 0, [None]),
'yn cannot have any None')
def test_xn_none(self):
self.assertEqual(iters.euler_step(.001, [None], 0),
'xn cannot have any None')
def test_yn_empty(self):
self.assertEqual(iters.euler_step(.001, 0, []), 'yn cannot be empty')
def test_xn_empty(self):
self.assertEqual(iters.euler_step(.001, [], 0), 'xn cannot be empty')
def test_rand_large_array(self):
xn = 100000 * np.random.rand(1, 10)
yn = 100000 * np.random.rand(1, 10)
self.assertTrue(
len(iters.euler_step(1, xn, yn)) == len(xn),
'output array should match input array length')