plot.ahull {alphahull}R Documentation

Plot the alpha-convex hull

Description

This function returns a plot of the α-convex hull. If desired, it also adds the Delaunay triangulation, Voronoi diagram and α-shape of the sample.

Usage

## S3 method for class 'ahull':
plot(x, add = FALSE, do.shape = FALSE, 
        wlines = c("none", "both", "del", "vor"), wpoints = TRUE, 
        number = FALSE, col = NULL, xlim = NULL, 
        ylim = NULL, lwd = NULL, ...)

Arguments

x Object of class "ahull".
add Logical, if TRUE add to a current plot.
do.shape Logical, indicates if the α-shape should also be plotted.
wlines "Which lines?". I.e. should the Delaunay triangulation be plotted (wlines='del'), should the Voronoi diagram be plotted (wlines='vor'), should both be plotted (wlines='both'), or none (wlines='none', the default)?
wpoints Logical, indicates if sample points should be plotted.
number Logical, defaulting to FALSE; if TRUE then the points plotted will be labelled with their index numbers.
col The colour numbers for plotting the α-convex hull, α-shape, data points, Delaunay triangulation, Voronoi diagram, and the point numbers, in that order; defaults to c(1,1,1,1,1,1). If fewer than six numbers are given, they are recycled. (If more than six numbers are given, the redundant ones are ignored.)
xlim The limits on the x-axis.
ylim The limits on the y-axis.
lwd The line widths for plotting the tesselations, the α-shape, and the α-convex hull, in that order; defaults to c(1,1,2).
... Arguments to be passed to methods, such as graphical parameters (see par).

See Also

ahull, ashape.

Examples

# Random sample in the unit square
x<-matrix(runif(100),nc=2)
# Value of alpha
alpha<-0.2
# alpha-convex hull
ahull.obj<-ahull(x,alpha=alpha)
# Plot including the alpha-convex hull in black, alpha-shape, 
# voronoi diagram and Delaunay triangulation 
plot(ahull.obj)
  

[Package alphahull version 0.1 Index]