Find the shortest distance between a point and line segments (not line)

[mrjean1]

Find the shortest distance between a point and line segments (not line)

[mrJean1]

Use LatLon method nearestOn the find the closest point. Then, use the distanceTo method to find the distance.

In addition, there are separate functions called nearestOn in the ellipsoidal and spherical modules and there are quite a few distance functions in module formy, named after the method employed.

[sbonaime]

I find a python solution here
https://www.geeksforgeeks.org/minimum-distance-from-a-point-to-the-line-segment-using-vectors/

[mrJean1]

A few more comments. The mechanism to find the closest point on a line or line segment is different for ellipsoidal and spherical LatLon method nearestOn.

Method sphericalTrigonometry.LatLon.nearestOn indirectly calls function nearestOn5 which uses the equirectangular approximation to compare distances.

Ellipsoidal nearestOn methods iterate and convert back and forth between geodetic and cartesian coordinates and use vectorial function vector3d.nearestOn** to get the closest point based on the dot product (in an azimuthal equidistant projection). For more details, see the references in ellipsoidal method intersections2.

__
**) That function is not public, a mistake. All 4 ellipsoidal modules export a function called nearestOn and both spherical modules have one named nearestOn3.