def test_comp_c(self):
GR = Grid(n=[5, 7], l=[
[-4., 3.],
[-1., 2.],
], k='c')
X = GR.comp([0, 0])
np.testing.assert_almost_equal(
X, np.array([[3.], [2.]])
)
X = GR.comp([4, 6])
np.testing.assert_almost_equal(
X, np.array([[-4.], [-1.]])
)
X = GR.comp([
[0, 4],
[0, 6],
])
np.testing.assert_almost_equal(
X, np.array([
[3., -4.],
[2., -1.],
])
)
def test_1ord_elements(self):
N = 5
SG = Grid(d=1, n=N + 1, l=[-1., 1.])
X = SG.comp()[0, :]
D = dif1(SG)
e = D[0, 0] - (2. * N**2 + 1.) / 6.
self.assertTrue(np.max(np.abs(e)) < 1.E-14)
e = D[0, 2] - 2. / (1. - X[2])
self.assertTrue(np.max(np.abs(e)) < 1.E-14)
e = D[0, 3] + 2. / (1. - X[3])
self.assertTrue(np.max(np.abs(e)) < 1.E-14)
e = D[4, 4] + X[4] / (1. - X[4]**2) / 2.
self.assertTrue(np.max(np.abs(e)) < 1.E-14)