Coverage for pySDC/projects/parallelSDC_reloaded/chemicalReaction_accuracy.py: 100%

1#!/usr/bin/env python3 

2# -*- coding: utf-8 -*- 

3""" 

4Created on Tue Dec 5 11:02:39 2023 

5 

6Script to investigate diagonal SDC on the ProtheroRobinson 

7(linear and non-linear) problem : 

8 

9- error VS time-step 

10- error VS computation cost 

11 

12Note : implementation in progress ... 

13""" 

14import numpy as np 

15import matplotlib.pyplot as plt 

16 

17from pySDC.projects.parallelSDC_reloaded.utils import getParamsSDC, getParamsRK, solutionSDC, solutionExact 

18 

19# Problem parameters 

20tEnd = 300 

21pName = "CHEMREC" 

22 

23 

24def getError(uNum, uRef): 

25 if uNum is None: # pragma: no cover 

26 return np.inf 

27 return max(np.linalg.norm(uRef[:, 0] - uNum[:, 0], np.inf), np.linalg.norm(uRef[:, 1] - uNum[:, 1], np.inf)) 

28 

29 

30def getCost(counters): 

31 nNewton, nRHS, tComp = counters 

32 return nNewton + nRHS 

33 

34 

35# Base variable parameters 

36nNodes = 4 

37quadType = 'RADAU-RIGHT' 

38nodeType = 'LEGENDRE' 

39parEfficiency = 1 / nNodes 

40 

41qDeltaList = [ 

42 'RK4', 

43 'ESDIRK53', 

44 'ESDIRK43', 

45 # 'IE', 'LU', 'IEpar', 'PIC', 

46 'MIN-SR-NS', 

47 'MIN-SR-S', 

48 'MIN-SR-FLEX', 

49 # "MIN3", 

50] 

51nStepsList = np.array([2, 5, 10, 20]) 

52nSweepList = [1, 2, 3, 4, 5, 6] 

53 

54qDeltaList = ['ESDIRK43', 'MIN-SR-S', 'MIN-SR-FLEX'] 

55nSweepList = [4] 

56 

57 

58symList = ['o', '^', 's', '>', '*', '<', 'p', '>'] * 10 

59fig, axs = plt.subplots(1, 2) 

60 

61dtVals = tEnd / nStepsList 

62 

63i = 0 

64for qDelta in qDeltaList: 

65 for nSweeps in nSweepList: 

66 sym = symList[i] 

67 i += 1 

68 

69 name = f"{qDelta}({nSweeps})" 

70 try: 

71 params = getParamsRK(qDelta) 

72 name = name[:-3] 

73 except KeyError: 

74 params = getParamsSDC( 

75 quadType=quadType, numNodes=nNodes, nodeType=nodeType, qDeltaI=qDelta, nSweeps=nSweeps 

76 ) 

77 print(f'computing for {name} ...') 

78 

79 errors = [] 

80 costs = [] 

81 

82 for nSteps in nStepsList: 

83 print(f' -- nSteps={nSteps} ...') 

84 

85 uRef = solutionExact(tEnd, nSteps, pName) 

86 

87 uSDC, counters, parallel = solutionSDC(tEnd, nSteps, params, pName) 

88 

89 err = getError(uSDC, uRef) 

90 errors.append(err) 

91 

92 cost = getCost(counters) 

93 if parallel: 

94 cost /= nNodes * parEfficiency 

95 costs.append(cost) 

96 

97 # error VS dt 

98 axs[0].loglog(dtVals, errors, sym + '-', label=name) 

99 # error VS cost 

100 axs[1].loglog(costs, errors, sym + '-', label=name) 

101 

102for i in range(2): 

103 axs[i].set( 

104 xlabel=r"$\Delta{t}$" if i == 0 else "cost", 

105 ylabel=r"$L_\infty$ error", 

106 ylim=(1e-9, 1e0), 

107 ) 

108 axs[i].legend(loc="lower right" if i == 0 else "lower left") 

109 axs[i].grid() 

110 

111fig.set_size_inches(12, 5) 

112fig.tight_layout()