# Trajectory¶

class acoular.trajectory.Trajectory

Bases: traits.has_traits.HasPrivateTraits

Describes a trajectory from sampled points.

Based on a discrete number of points in space and time, a continuous trajectory is calculated using spline interpolation of positions between samples.

points = Dict(key_trait = Float, value_trait = Tuple(Float, Float, Float), desc = "sampled positions along the trajectory")

Dictionary that assigns discrete time instants (keys) to sampled (x, y, z) positions along the trajectory (values).

interval = Property()

Tuple of the start and end time, is set automatically (depending on points).

tck = Property()

Spline data, internal use.

location(t, der=0)

Returns the positions for one or more instants in time.

Parameters: t : array of floats Instances in time to calculate the positions at. der : integer The order of derivative of the spline to compute, defaults to 0. (x, y, z) : tuple with arrays of floats Positions at the given times; x, y and z have the same shape as t.
traj(t_start, t_end=None, delta_t=None, der=0)

Python generator that yields locations along the trajectory.

Parameters: t_start : float Starting time of the trajectory, defaults to the earliest time in points. t_end : float Ending time of the trajectory, defaults to the latest time in points. delta_t : float Time interval between yielded trajectory points, defaults to earliest time in points. (x, y, z) : tuples of floats Positions at the desired times are yielded.

Examples

x.traj(0.1)
Yields the position every 0.1 s within the given interval.
x.traj(2.5, 4.5, 0.1)
Yields the position every 0.1 s between 2.5 s and 4.5 s.
x.traj(0.1, der=1)
Yields the 1st derivative of the spline (= velocity vector) every 0.1 s within the given interval.