convexHullAM {contoureR} | R Documentation |
This function is the R interface to the C++ implementation of Andrews Monotone, a well known algorithm for solving
the convex hull in O(nlogn)
time complexity.
convexHullAM_Indexes(x, y, includeColinear=FALSE,zeroBased = TRUE) convexHullAM_Points(x, y,includeColinear=FALSE)
x |
NumericVector of x values |
y |
NumericVector of y values |
includeColinear |
whether to inlude points that line ON the hull, by default this is set to FALSE, as this is the true definition of the convex hull. |
zeroBased |
Whether the return indexes should be zero based (true, for use in C++), or One-Based (false, for use in R). |
convexHullAM_Indexes
returns an integer vector of the indexes of the points,
whilst convexHullAM_Points
returns an n x 2
matrix of the points themselves.
library(contoureR) library(ggplot2) set.seed(1) x = runif(100) y = runif(100) ch = convexHullAM_Indexes(x,y,includeColinear=FALSE,zeroBased = FALSE) ggplot(data.frame(x,y),aes(x,y)) + geom_point() + geom_path(data=data.frame(x,y)[ch,],colour="red")