Coverage for src/flexfrac1d/lib/att.py: 100%

1"""Attenuation parameterisations.""" 

2 

3import enum 

4import typing 

5 

6import attrs 

7import numpy as np 

8 

9 

10def no_attenuation(): 

11 """No attenuation. 

12 

13 Waves propagate indifinitely, as if the ice cover is perfectly elastic and 

14 the fluid perfectly inviscid. 

15 

16 Returns 

17 ------- 

18 typing.Literal[0] 

19 Amplitude attenuation, in m^-1 

20 

21 Notes 

22 ----- 

23 The attenuation is defined as: 

24 

25 .. math:: 

26 

27 \alpha_j = 0 \forall j. 

28 

29 """ 

30 return 0 

31 

32 

33def parameterisation_01(thickness: float, wavenumbers: np.ndarray) -> np.ndarray: 

34 """Parameterised attenuation for individual wave modes. 

35 

36 Parameters 

37 ---------- 

38 thickness : float 

39 Ice thickness, in m 

40 wavenumbers : np.ndarray 

41 Propagating wavenumbers, in rad m^-1 

42 

43 Returns 

44 ------- 

45 np.ndarray 

46 Amplitude attenuation, in m^-1 

47 

48 Notes 

49 ----- 

50 The attenuation is defined as: 

51 

52 .. math:: 

53 

54 \alpha_j = \frac{1}{4} {k_j}^2 h. 

55 

56 """ 

57 return wavenumbers**2 * thickness / 4 

58 

59 

60class AttenuationParameterisation(enum.Enum): 

61 NO = 0 

62 PARAM_01 = 1 

63 

64 

65@attrs.frozen 

66class AttenuationSpecification: 

67 function: typing.Callable 

68 args: str | None = None 

69 kwargs: dict[str, typing.Any] = attrs.field(factory=dict) 

70 

71 

72Attenuation: typing.TypeAlias = AttenuationParameterisation | AttenuationSpecification