Coverage for pySDC/tutorial/step_4/B_multilevel_hierarchy.py: 100%

1from pathlib import Path 

2 

3from pySDC.core.Step import step 

4 

5from pySDC.implementations.problem_classes.HeatEquation_ND_FD import heatNd_unforced 

6from pySDC.implementations.sweeper_classes.generic_implicit import generic_implicit 

7from pySDC.implementations.transfer_classes.TransferMesh import mesh_to_mesh 

8 

9 

10def main(): 

11 """ 

12 A simple test program to set up a full step hierarchy 

13 """ 

14 

15 # initialize level parameters 

16 level_params = dict() 

17 level_params['restol'] = 1e-10 

18 level_params['dt'] = 0.1 

19 

20 # initialize sweeper parameters 

21 sweeper_params = dict() 

22 sweeper_params['quad_type'] = 'RADAU-RIGHT' 

23 sweeper_params['num_nodes'] = [5, 3] 

24 sweeper_params['QI'] = 'LU' 

25 

26 # initialize problem parameters 

27 problem_params = dict() 

28 problem_params['nu'] = 0.1 # diffusion coefficient 

29 problem_params['freq'] = 4 # frequency for the test value 

30 problem_params['nvars'] = [31, 15, 7] # number of degrees of freedom for each level 

31 problem_params['bc'] = 'dirichlet-zero' # boundary conditions 

32 

33 # initialize step parameters 

34 step_params = dict() 

35 step_params['maxiter'] = 20 

36 

37 # initialize space transfer parameters 

38 space_transfer_params = dict() 

39 space_transfer_params['rorder'] = 2 

40 space_transfer_params['iorder'] = 2 

41 

42 # fill description dictionary for easy step instantiation 

43 description = dict() 

44 description['problem_class'] = heatNd_unforced 

45 description['problem_params'] = problem_params 

46 description['sweeper_class'] = generic_implicit 

47 description['sweeper_params'] = sweeper_params 

48 description['level_params'] = level_params 

49 description['step_params'] = step_params 

50 description['space_transfer_class'] = mesh_to_mesh 

51 description['space_transfer_params'] = space_transfer_params 

52 

53 # now the description contains more or less everything we need to create a step with multiple levels 

54 S = step(description=description) 

55 

56 # print out and check 

57 Path("data").mkdir(parents=True, exist_ok=True) 

58 f = open('data/step_4_B_out.txt', 'w') 

59 for l in range(len(S.levels)): 

60 L = S.levels[l] 

61 out = 'Level %2i: nvars = %4i -- nnodes = %2i' % (l, L.prob.nvars[0], L.sweep.coll.num_nodes) 

62 f.write(out + '\n') 

63 print(out) 

64 assert L.prob.nvars[0] == problem_params['nvars'][min(l, len(problem_params['nvars']) - 1)], ( 

65 "ERROR: number of DOFs is not correct on this level, got %s" % L.prob.nvars 

66 ) 

67 assert L.sweep.coll.num_nodes == sweeper_params['num_nodes'][min(l, len(sweeper_params['num_nodes']) - 1)], ( 

68 "ERROR: number of nodes is not correct on this level, got %s" % L.sweep.coll.num_nodes 

69 ) 

70 f.close() 

71 

72 

73if __name__ == "__main__": 

74 main()