Coverage for src/gncpy/dynamics/basic/dynamics_base.py: 80%

1from abc import abstractmethod, ABC 

2 

3 

4class DynamicsBase(ABC): 

5 r"""Defines common attributes for all dynamics models. 

6 

7 Attributes 

8 ---------- 

9 control_model : callable or list of callables, optional 

10 For objects of :class:`gncpy.dynamics.LinearDynamicsBase` it is a 

11 callable with the signature `t, *ctrl_args` and returns the 

12 input matrix :math:`G_k` from :math:`x_{k+1} = F_k x_k + G_k u_k`. 

13 For objects of :class:`gncpy.dynamics.NonlinearDynamicsBase` it is a 

14 list of callables where each callable returns the modification to the 

15 corresponding state, :math:`g(t, x_i, u_i)`, in the differential equation 

16 :math:`\dot{x}_i = f(t, x_i) + g(t, x_i, u_i)` and has the signature 

17 `t, x, u, *ctrl_args`. 

18 state_constraint : callable 

19 Has the signature `t, x` where `t` is the current timestep and `x` 

20 is the propagated state. It returns the propagated state with 

21 any constraints applied to it. 

22 """ 

23 

24 state_names = () 

25 """Tuple of strings for the name of each state. The order should match 

26 that of the state vector. 

27 """ 

28 

29 def __init__(self, control_model=None, state_constraint=None): 

30 super().__init__() 

31 self._control_model = control_model 

32 self.state_constraint = state_constraint 

33 

34 @property 

35 def allow_cpp(self): 

36 return False 

37 

38 @property 

39 def control_model(self): 

40 return self._control_model 

41 

42 @control_model.setter 

43 def control_model(self, model): 

44 self._control_model = model 

45 

46 @abstractmethod 

47 def propagate_state(self, timestep, state, u=None, state_args=None, ctrl_args=None): 

48 """Abstract method for propagating the state forward in time. 

49 

50 Must be overridden in child classes. 

51 

52 Parameters 

53 ---------- 

54 timestep : float 

55 timestep. 

56 state : N x 1 numpy array 

57 state vector. 

58 u : Nu x 1 numpy array, optional 

59 Control effort vector. The default is None. 

60 state_args : tuple, optional 

61 Additional arguments needed by the `get_state_mat` function. The 

62 default is (). 

63 ctrl_args : tuple, optional 

64 Additional arguments needed by the get input mat function. The 

65 default is (). Only used if a control effort is supplied. 

66 

67 Raises 

68 ------ 

69 NotImplementedError 

70 If child class does not implement this function. 

71 

72 Returns 

73 ------- 

74 next_state : N x 1 numpy array 

75 The propagated state. 

76 """ 

77 raise NotImplementedError() 

78 

79 @abstractmethod 

80 def get_state_mat(self, timestep, *args, **kwargs): 

81 """Abstract method for getting the discrete time state matrix. 

82 

83 Must be overridden in child classes. 

84 

85 Parameters 

86 ---------- 

87 timestep : float 

88 timestep. 

89 args : tuple, optional 

90 any additional arguments needed. 

91 

92 Returns 

93 ------- 

94 N x N numpy array 

95 state matrix. 

96 """ 

97 raise NotImplementedError() 

98 

99 @abstractmethod 

100 def get_input_mat(self, timestep, *args, **kwargs): 

101 """Should return the input matrix. 

102 

103 Must be overridden by the child class. 

104 

105 Parameters 

106 ---------- 

107 timestep : float 

108 Current timestep. 

109 *args : tuple 

110 Placeholder for additional arguments. 

111 **kwargs : dict 

112 Placeholder for additional arguments. 

113 

114 Raises 

115 ------ 

116 NotImplementedError 

117 Child class must implement this. 

118 

119 Returns 

120 ------- 

121 N x Nu numpy array 

122 input matrix for the system 

123 """ 

124 raise NotImplementedError() 

125