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javascriptarraysalgorithmpolygonpoint-in-polygon

Javascript find furthest coordinate from a certain coordinate in an array of coordinates

I know the center coordinates and an array of all coordinates of a polygon. How can I find out which coordinate is the furthest coordinate for the center point with Javascript?

Center of bounds:

lat: -13.647141573542923lng: 109.75651876851946

Coordinates of the 4 polygon paths:

"lat:-9.10209673872643 , lng: 108.10546875"

"lat:-16.97274101999901 , lng: 91.58203125"

"lat:-17.644022027872722 , lng: 120.234375"

"lat:-8.407168163601074 , lng: 120.41015625"

centroid

Solution

  • The canonical way of doing things:

    • Figure out how to calculate distances with longitutdes/latitudes. A quick Google search, for example, brings up this.
    • Iterate over all points p_i and calculate the distance d_i to the center point.
    • The point p_k with d_k = max_j d_j will be the point you are looking for.

    For distance calculation keep in mind that you can save yourself any operation that won't change the information "further away than", i.e. in euclidic coordinates you could save yourself taking the square root. Also multiplications by any constant can be omitted for this (as long as you don't need to actually know the distance, but only the information which point is the furthest away).