def test_error_tracker():
delta_x = 0.01 * np.ones(100)
exact = lambda t: np.linspace(0, 1, 100) + t
params = Data()
params.error_norm = 1
params.plotter = Data()
params.plotter.never_plot = True
e1 = ErrorTracker(Mesh(delta_x), exact, params)
params.error_norm = 2
e2 = ErrorTracker(Mesh(delta_x), exact, params)
for i in range(1, 10):
# the exact result is x + i
e1.update(e1.mesh.x + 0.9 * i, float(i), 1.0)
# in any norm the error should be 0.i
assert(abs(e1.error[i] - i * 0.1) <= 1e-9)
new_val = exact(i)
new_val[0] = 0
# the difference
e2.update(new_val, float(i), 1.0)
# L2 norm of the error should be 0.(i + 1)
assert(abs(e2.error[i] - (i * 0.01)) <= 1e-9)
