Project points onto line segments (Euclidean/planar geometry)

Vectorized computation of the distance from each point in P to each line segment defined by S (starts) and E (ends), and the distance along the segment to the projection of the point.

Usage

project_points_simple(s, e, p, m, n, v, vv, clamp = FALSE, tol = 0)

Arguments

s

An n x 2 matrix of segment start coordinates.

e

An n x 2 matrix of segment end coordinates.

p

An m x 2 matrix of point coordinates.

m

Number of points (nrow(p)).

n

Number of line segments (nrow(s)).

v

e - s, precomputed segment vectors.

vv

rowSums(v^2), precomputed squared segment lengths.

clamp

If TRUE constrain the projected fraction to [0, 1]. If FALSE (default) projections falling outside the segment are set to NA.

tol

Segments with squared length at or below this threshold are treated as having zero length (projected fraction set to 0).

Value

A list with dist_to_line and dist_along, each a vector of length m * n (point index varying fastest).