def test_evaluate_gradient():
grid = StructuredGrid()
grid.update_property('Y', grid.nodes[:, 1])
vector = np.mean(grid.evaluate_gradient(grid.barycentre(), 'Y'), axis=0)
# vector/=np.linalg.norm(vector)
assert np.sum(vector - np.array([0, grid.step_vector[1], 0])) == 0
def test_get_element():
grid = StructuredGrid()
point = grid.barycentre()[[0], :]
idc, inside = grid.position_to_cell_corners(point)
bary = np.mean(grid.nodes[idc, :], axis=0)
assert np.sum(point - bary) == 0
def test_evaluate_value():
grid = StructuredGrid()
grid.update_property('X', grid.nodes[:, 0])
assert np.sum(grid.barycentre()[:, 0] -
grid.evaluate_value(grid.barycentre(), 'X')) == 0