How to perform DTW or EDR with 3 vectors?
21 views (last 30 days)
Hello all! I haven't worked on these stuff before and my knowledge about them only comes from internet, so I'd be happy if you could help me with my problem.
I have trajectories (in 3D) of some markers obtained from a MOCAP system. During the experiment, each subject performed several movements, and for each, we captured it 3 times. So, I have 3 trials for one movement, and I would like to average them (or create one time-series in general terms). Moreover, I am thinking to fill the missing points that are occured during only in some of those trials. However, I need to perform a "temporal normalization" first, since the events of the movement occured at slightly different instances due to patients' velocities. I came across with DTW(Dynamic Time Warping) and EDR(Edit Distance on Real Signals), but they both are used with two signals at a time. I would to use them for all 3 signals in order to obtain a common time-warped or edited signal.
Since I can't use 3 of them at the same time, I tried with pairs of them, for example:
[d1,ix1,iy1] = dtw(trial1,trial2);
[d2,ix2,iy2] = dtw(trial1,trial3);
But the new trial1 vectors i.e. trial1(ix1) and trial1(ix2) are different from each other.
Is there any way that I can use all three of my signal in DTW and/or EDR? (Maybe utilizing in a way the pairs of signals or anchoring one signal etc.)
Thanks in advance
Also, I have another question regarding to DTW (How to set proper maxsamp value in Dynamic Time Warping) with only 2 signals.