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Re: Decision whether point lies within closed contour

• To: mathgroup at smc.vnet.net
• Subject: [mg131819] Re: Decision whether point lies within closed contour
• From: Fred Simons <f.h.simons at tue.nl>
• Date: Wed, 9 Oct 2013 22:11:47 -0400 (EDT)
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• References: <20131009061059.333A869F1@smc.vnet.net>

Yes, such an algorithm exists. Let P be the point for which you want to 
decide whether it is inside of outside the polygon given by the points 
A0, A1,..., An .  For each i compute the angle Ai P Ai+1. Then P is 
outside the polygon if and only if  these angles sum up to 0.

Regards,

Fred Simons
Eindhoven University of Technology


Op 09-10-13 8:10, Dr. Robert Kragler schreef:
> Does an algorithm or even a Mathematica procedure exist to decide whether a
> points is located inside or outside a closed contour resp. closed polygonal line?
>
> Thanks for any reply
>
> Robert Kragler
>
>
>
>
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• References:
  • Decision whether point lies within closed contour
    • From: "Dr. Robert Kragler" <kragler@hs-weingarten.de>