isPointOnBoundary: Check if a point is on a polygon boundary

In henna: A Versatile Visualization Suite

Check if a point is on a polygon boundary

Description

This function checks if a point P is on a polygon boundary.

Usage

isPointOnBoundary(xPoint, yPoint, boundary)

Arguments

xPoint	x coordinate of point P.
yPoint	y coordinate of point P.
boundary	A data frame with four columns representing segments comprising the boundary.

Value

Logical; whether the point is on the boundary.

Examples

pointsDF <- data.frame(x = c(1, 2, 4, 7, 10,
12, 13, 15, 16),
y = c(1, 1, 2, 3, 3, 2,
1, 2, 1))

hullIndices <- grDevices::chull(pointsDF[, 1], pointsDF[, 2])
hull <- convexHull(pointsDF, hullIndices)
hullSegments <- pointsToSegments(hull)

isPointOnBoundary(2, 3, hullSegments)

henna documentation built on Feb. 17, 2026, 9:08 a.m.