Velocity vector orientation

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ptjeong ptjeong
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Velocity vector orientation

I would like to study collective migration behaviour of cells using PIV.
How can I extract velocity vector orientation using PIVlab?

Many thanks,
Peter
ptjeong ptjeong
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Re: Velocity vector orientation

In the end I would like to generate data plots like these:

William William
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Re: Velocity vector orientation

In reply to this post by ptjeong
You can extract the velocity data from PIVlab to Matlab or Excel or whatever, and then calculate the angle of each vector, and then do this circular histogram plot.

Please consider donating for the PIVlab project:
http://paypal.me/pools/c/81Y8wBVi4y

The developer needs to update to a recent Matlab release in order to keep the project running.

ptjeong ptjeong
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Re: Velocity vector orientation

Hi William,

thank you for your reply!
Upon reading up a little bit and realised that this is a very primitive question.
To be honest, so is my mathematical understanding of the subject matter.

As far as I could understand, the u and v components are in the meteorological convention,
i.e. u component is positive for a west to east flow and the v component is positive for south to north flow?

To convert these I would use the formula:
Speed = SQRT( u^2 + v^2)
Direction = arctan(v / u)

Is this correct?
William William
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Re: Velocity vector orientation

That sounds good!

Please consider donating for the PIVlab project:
http://paypal.me/pools/c/81Y8wBVi4y

The developer needs to update to a recent Matlab release in order to keep the project running.