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From: "smar " <smar234@yahoo.com>
Newsgroups: comp.soft-sys.matlab
Subject: How to synchronize two 3D Trajectories
Date: Thu, 11 Dec 2008 02:12:02 +0000 (UTC)
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Hello,
There are two 3D Trajectories in Matlab. 
A = [x y z]   rows = n   (about 20,000)
B = [x y z]   rows = m   (about 50,000)


Both trajectories A and B represent a same 3D path in space. Thus all 3D points on trajectory A should have their corresponding 3D points in trajectory B.

Both trajectories are generated from different sources. 
There are two constraints:

1.	There are small deviations (in ?m) in corresponding x y and z values of corresponding 3D points.

2.	There is a small shift (variable along the trajectory) in relative position of corresponding 3D points in trajectories. In other words separation between points (point&#8217;s density) is different over the trajectory.


The final task is to calculate these deviations. But first problem is to find the corresponding points in both trajectories (synchronizing the both trajectories or searching for the matching points). 


Finally the deviation would be calculated such as:
For example 

  Points in A   - corresponding points in B =   deviations
--
--
--

[34.00 56.05 67.06] - [34.01 56.04 67.07] = [-00.01 00.01 -00.07]
[34.50 56.55 67.50] - [34.52 56.57 67.48] = [-00.02 -00.02 00.02]
[34.70 56.75 67.76] - [34.71 56.74 67.77] = [-00.01 -00.01 -00.01]
--
--
--

Need guideline/Help needed 

&#8226;	How I can syschronize the trajectories or find the maching points for trajectory A in trajectory B (any Matlab functions or methods ?)
Thanks in advance for an expected help

Regards