I'm trying to find out whether a point in lat, lon lie inside a polygon formed by four random points on earth.
Can someone help me out with a algorithm with sudo code in java.
Thanks in advance.
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1Pl share what you have tried? – Rajen Raiyarela Nov 19 '15 at 10:54
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Do you have any preferred technology to use? – Wernfried Domscheit Nov 21 '15 at 12:19
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As long as the polygon does not intersect the poles or the datum limit (the meridian at the border of longitude -180 / 180),
you can use a simple point in polygon algorithm, written for cartesian space.
In this special case there is no need to convert to cartesian coordinates.
Just use x = longitude and y = latitude.
The point in polygon algorithm should be based on on the "ray intersection" method. (A ray parallel to x-axis through the point of question, that is outside always intersects the polygon an even number of times, while an point inside always an odd number of times.
Such a code is only a few lines long.
AlexWien
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