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I need to smooth xy co-ordinates. see the image:

enter image description here

In this case, i need to remove 5,6,7,8 and 9th co-ordinates or need to make those co-ordinates as a straight line between 4th and 5th. is there any logic to do this?

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Are you asking how to identify the nodes to be removed or simply how to remove them once they have been identified? The latter is so trivial I would presume you mean the former, but that brings up the crucial question: on what basis have you determined that these nodes should be removed? After all, they constitute more than half the length of this path, so arguably those nodes should be kept and nodes 0..3 and 11..14 should be removed instead! –  whuber May 10 '13 at 13:50
    
@whuber I need to identify the nodes(5,6,7,8 and 9) to remove . Assume the average distance is 2m between the nodes from 0 to 4 and the average distance is 1m between the nodes from 10 to 14. but for 5 to 9 the average distance is too high (Ex: 10m).Like that i can determine that those nodes should be removed.But i'm not sure whether this logic is correct. –  venkat May 11 '13 at 6:12
    
Based on the information you have given it is not possible to tell whether that logic is correct, Venkat. For instance, if the coordinates were obtained by a GPS at regular time intervals, then your rule would eliminate all nodes where the unit was moving the fastest! More information is needed in order to resolve your question. –  whuber May 11 '13 at 14:08
    
Yes the coordinates were obtained by a GPS at regular time intervals –  venkat May 13 '13 at 6:43
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1 Answer 1

It doesen't seem to be smoothing but rather removing of outliers you are looking for. Maybe you will find some help in this discussion: What algorithm should I use to remove outliers in trace data?

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