Lets some objects make complex spiral moving in 3D and we have get their trajectories projected on a plane.
How to find a median trajectory of such movements and estimate the amplitudes of spirals?
I assume that this requires averaging the coordinates of the trajectories, then somehow finding the distances from the extreme points of the trajectories to the midline. But I don't know a concrete algorithm for this. Can someone suggest this algorithm?
By median trajectory I mean a line that ges between path waves, something like linew on a picture below.
This is a case for a Kalman filter, but this method is a little complicated.
A simpler one is a moving average, with a number of samples that covers as closes as possible to a full period (which you can estimate visually).
Regarding the distances, you can compute the shortest Euclidean distance of every point to the midline (using a line-to-segment function). This will yield an alternating plot, which you can smoothen with a moving maximum (rather than average) over a period.