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javascriptopenlayers

How to find the angle between three points with openlayers?

I use openlayers version 6.5.

I want to find the angle between two lines or three points.

Is there a library to reference or how to get it?

enter image description here

No related library was found. Should I solve it mathematically?

Solution

  • You can use dot product:

    The dot product of two normalized vectors is equal to angle between them. In general case when the vectors are not normalized the equation is the following:

    cos(a^b) = dot(a,b) / length(a) / length(b)

    Thus:

    a^b = arccos(dot(a,b) / length(a) / length(b))

    Or:

    a^b = arccos( (a.x*b.x + a.y*b.y + a.z*b.z) / sqrt(a.x^2+a.y^2+a.z^2) / sqrt(b.x^2+b.y^2+b.z^2) )