Coverage for pySDC/projects/parallelSDC_reloaded/scripts/fig01_conv.py: 100%

1#!/usr/bin/env python3 

2# -*- coding: utf-8 -*- 

3""" 

4Created on Tue Jan 9 16:00:41 2024 

5 

6Convergence plots (on Dahlquist) for the article 

7""" 

8import os 

9import numpy as np 

10 

11from pySDC.projects.parallelSDC_reloaded.utils import getParamsSDC, solutionSDC, plt 

12from pySDC.helpers.testing import DataChecker 

13 

14data = DataChecker(__file__) 

15 

16PATH = '/' + os.path.join(*__file__.split('/')[:-1]) 

17SCRIPT = __file__.split('/')[-1].split('.')[0] 

18 

19# Script parameters 

20lam = 1j 

21tEnd = 2 * np.pi 

22nStepsList = np.array([2, 5, 10, 20, 50, 100, 200, 500, 1000]) 

23dtVals = tEnd / nStepsList 

24 

25# Collocation parameters 

26nodeType = "LEGENDRE" 

27 

28 

29def getError(uNum, uRef): 

30 if uNum is None: # pragma: no cover 

31 return np.inf 

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

33 

34 

35# Configuration 

36# (nNodes, quadType, sweepType) 

37config = [ 

38 (4, "RADAU-RIGHT", "MIN-SR-NS"), 

39 (5, "LOBATTO", "MIN-SR-NS"), 

40 (4, "RADAU-RIGHT", "MIN-SR-S"), 

41 (5, "LOBATTO", "MIN-SR-S"), 

42 (4, "RADAU-RIGHT", "MIN-SR-FLEX"), 

43 (5, "LOBATTO", "MIN-SR-FLEX"), 

44] 

45 

46# ----------------------------------------------------------------------------- 

47# Script execution 

48# ----------------------------------------------------------------------------- 

49for nNodes, quadType, sweepType in config: 

50 # Schemes parameters 

51 schemes = [ 

52 # ("RK4", None), ("ESDIRK53", None), 

53 *[(sweepType, i) for i in range(1, nNodes + 1)] 

54 ] 

55 

56 # Plot styles 

57 styles = [ 

58 # dict(ls="--", c="gray"), dict(ls="-.", c="gray"), 

59 dict(ls="-", marker='o'), 

60 dict(ls="-", marker='>'), 

61 dict(ls="-", marker='s'), 

62 dict(ls="-", marker='^'), 

63 dict(ls="-", marker='*'), 

64 ] 

65 

66 # Figure generation 

67 figName = f"{sweepType}_{quadType}" 

68 plt.figure(f"{sweepType}_{quadType}") 

69 for (qDelta, nSweeps), style in zip(schemes, styles): 

70 params = getParamsSDC(quadType, nNodes, qDelta, nSweeps, nodeType) 

71 label = f"$K={nSweeps}$" 

72 errors = [] 

73 

74 for nSteps in nStepsList: 

75 uNum, counters, parallel = solutionSDC(tEnd, nSteps, params, 'DAHLQUIST', lambdas=np.array([lam])) 

76 

77 tVals = np.linspace(0, tEnd, nSteps + 1) 

78 uExact = np.exp(lam * tVals) 

79 

80 err = getError(uNum, uExact) 

81 errors.append(err) 

82 

83 plt.loglog(dtVals, errors, **style, label=label) 

84 

85 data.storeAndCheck(f"{SCRIPT}_{figName}_{label}", errors) 

86 

87 if nSweeps is not None: 

88 plt.loglog(dtVals, (0.1 * dtVals) ** nSweeps, '--', c='gray', lw=1.5) 

89 

90 plt.legend() 

91 plt.xlabel(r"$\Delta{t}$") 

92 plt.ylabel(r"$L_\infty$ error") 

93 plt.grid(True) 

94 plt.tight_layout() 

95 plt.savefig(f"{PATH}/{SCRIPT}_{figName}.pdf") 

96 

97data.writeToJSON()