deldir (version 0.0-19)

plot.tile.list: Plot Dirchlet (Voronoi) tiles

Description

A method for plot. Plots (sequentially) the tiles associated with each point in the set being tessellated.

Usage

## S3 method for class 'tile.list':
plot(x, verbose = FALSE, close=FALSE, pch=1,
                         polycol=NA, showpoints=TRUE, showrect=FALSE,
                         add=FALSE, asp=1, xlab = "x", ylab = "y",
                         main = "", ...)

Arguments

x

A list of the tiles in a tessellation, as produced the function tile.list().

verbose

Logical scalar; if TRUE the tiles are plotted one at a time (with a ``Go?'' prompt after each) so that the process can be watched.

close

Logical scalar; if TRUE the outer edges of of the tiles (i.e. the edges of the enclosing rectangle) are drawn. Otherwise tiles on the periphery of the tessellation are left ``open''.

pch

The plotting character for plotting the points of the pattern which was tessellated. Ignored if showpoints is FALSE.

polycol

Optional vector of integers (or NAs); the $i$-th entry indicates with which colour to fill the $i$-th tile. Note that an NA indicates the use of no colour at all.

showpoints

Logical scalar; if TRUE the points of the pattern which was tesselated are plotted.

showrect

Logical scalar; show the enclosing rectangle rw (see deldir()) be plotted?

add

Logical scalar; should the plot of the tiles be added to an existing plot?

asp

The aspect ratio of the plot; integer scalar or NA. Set this argument equal to NA to allow the data to determine the aspect ratio and hence to make the plot occupy the complete plotting region in both x and

xlab

Label for the x-axis (used only if add is FALSE).

ylab

Label for the y-axis (used only if add is FALSE).

main

A title for the plot (used only if add is FALSE).

...

Optional arguments; not used. There for consistency with the generic plot function.

Value

• NULL; side effect is a plot.

Warnings

The default value for verbose was formerly TRUE; it is now FALSE.

The user is strongly advised not to set the value of asp but rather to leave asp equal to its default value of 1. Any other value distorts the tesselation and destroys the perpendicular appearance of lines which are indeed perpendicular. (And conversely can cause lines which are not perpendicular to appear as if they are.)

The argument asp was added at the request of Zubin Dowlaty.

See Also

deldir(), tile.list() triang.list() plot.triang.list()

Examples

x <- runif(20)
  y <- runif(20)
  z <- deldir(x,y,rw=c(0,1,0,1))
  w <- tile.list(z)
  plot(w)
  ccc <- heat.colors(20) # Or topo.colors(20), or terrain.colors(20)
                         # or cm.colors(20), or rainbox(20).
  plot(w,polycol=ccc,close=TRUE)