# plot.ahull {alphahull}

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

## Not run: # 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 pink, alpha-shape in blue, # sample points in black, voronoi diagram in green # and Delaunay triangulation in red plot(ahull.obj, do.shape = TRUE, wlines = "both", col = c(6, 4, 1, 2, 3)) # Random sample from a uniform distribution on a Koch snowflake # with initial side length 1 and 3 iterations x <- rkoch(2000, side = 1, niter = 3) # Value of alpha alpha <- 0.05 # Alpha-convex hull ahull.obj <- ahull(x, alpha = alpha) plot(ahull.obj) ## End(Not run)

Documentation reproduced from package alphahull, version 2.1. License: file LICENSE