Coverage for src/beamme/four_c/function_utility.py: 91%

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22"""This module implements utility functions to create 4C space time function.""" 

23 

24import numpy as _np 

25 

26from beamme.core.function import Function as _Function 

27 

28 

29def create_linear_interpolation_dict( 

30 times: list[float], values: list[float], *, variable_name="var", variable_index=0 

31): 

32 """Create a string that describes a variable that is linear interpolated over time. 

33 

34 Args 

35 times, values: 

36 Time and values that will be interpolated with piecewise linear functions 

37 variable_name: 

38 Name of the created variable 

39 variable_index: 

40 Index of this created variable 

41 """ 

42 if not len(times) == len(values): 

43 raise ValueError( 

44 f"The dimensions of time ({len(times)}) and values ({len(values)}) do not match" 

45 ) 

46 

47 times_appended = _np.array(times) 

48 values_appended = _np.array(values) 

49 t_max = _np.max(times_appended) 

50 times_appended = _np.insert(times_appended, 0, -1000.0, axis=0) 

51 times_appended = _np.append(times_appended, [t_max + 1000.0]) 

52 values_appended = _np.insert(values_appended, 0, values[0], axis=0) 

53 values_appended = _np.append(values_appended, values_appended[-1]) 

54 return { 

55 "VARIABLE": variable_index, 

56 "NAME": variable_name, 

57 "TYPE": "linearinterpolation", 

58 "NUMPOINTS": len(times_appended), 

59 "TIMES": times_appended.tolist(), 

60 "VALUES": values_appended.tolist(), 

61 } 

62 

63 

64def create_linear_interpolation_function( 

65 times: list[float], 

66 values: list[float], 

67 *, 

68 function_type="SYMBOLIC_FUNCTION_OF_SPACE_TIME", 

69): 

70 """Create a function that describes a linear interpolation between the given time 

71 points and values. Before and after it will be constant. 

72 

73 Args 

74 ---- 

75 times, values: 

76 Time and values that will be interpolated with piecewise linear functions 

77 """ 

78 function_dict = create_linear_interpolation_dict(times, values, variable_name="var") 

79 return _Function([{function_type: "var"}, function_dict]) 

80 

81 

82def ensure_length_of_function_array(function_array: list, length: int = 3): 

83 """Performs size check of a function array and appends the function array to the 

84 given length, if a list with only one item is provided. 

85 

86 Args: 

87 function_array: list with functions 

88 length: expected length of function array 

89 

90 Returns: 

91 function_array: list with functions with provided length 

92 """ 

93 # extend items of function automatically if it is only provided once 

94 if len(function_array) == 1: 

95 function_array = function_array * length 

96 

97 if len(function_array) != length: 

98 raise ValueError( 

99 f"The function array must have length {length} not {len(function_array)}." 

100 ) 

101 return function_array