frispy.equations_of_motion

Module Contents

Classes

EOM	EOM is short for "equations of motion" is used to run the ODE solver

class frispy.equations_of_motion.EOM(environment: frispy.environment.Environment = Environment(), model: frispy.model.Model = Model(), trajectory: frispy.trajectory.Trajectory = Trajectory())

EOM is short for “equations of motion” is used to run the ODE solver from scipy. It takes in a model for the disc, the trajectory object, the environment, and implements the functions for calculating forces and torques.

compute_forces(self, phi: float, theta: float, velocity: numpy.ndarray, ang_velocity: numpy.ndarray) → Dict[str, Union[float, numpy.ndarray, Dict[str, numpy.ndarray]]]

Compute the lift, drag, and gravitational forces on the disc.

compute_torques(self, velocity: numpy.ndarray, ang_velocity: numpy.ndarray, res: Dict[str, Union[float, numpy.ndarray, Dict[str, numpy.ndarray]]]) → Dict[str, Union[float, numpy.ndarray, Dict[str, numpy.ndarray]]]

Compute the torque around each principle axis.

compute_derivatives(self, time: float, coordinates: numpy.ndarray) → numpy.ndarray

Right hand side of the ordinary differential equations. This is supplied to scipy.integrate.solve_ivp(). See this page for more information about its fun argument.

Parameters

• time (float) – instantanious time of the system

• coordinates (np.ndarray) – kinematic variables of the disc

Returns

derivatives of all coordinates