spatstat (version 1.11-4)

plot.owin: Plot a Spatial Window

Description

Plot a two-dimensional window of observation for a spatial point pattern

Usage

## S3 method for class 'owin':
plot(x, main, add=FALSE, \dots, box, edge=0.04)

Arguments

x

The window to be plotted. An object of class owin, or data which can be converted into this format by as.owin().

main

text to be displayed as a title above the plot.

add

logical flag: if TRUE, draw the window in the current plot; if FALSE, generate a new plot.

...

extra arguments passed to the generic plot function.

box

logical flag; if TRUE, plot the enclosing rectangular box

edge

nonnegative number; the plotting region will have coordinate limits that are 1 + edge times as large as the limits of the rectangular box that encloses the pattern.

Value

• none.

Details

This is the plot method for the class owin. The action is to plot the boundary of the window on the current plot device, using equal scales on the x and y axes.

If the window x is of type "rectangle" or "polygonal", the boundary of the window is plotted as a polygon or series of polygons. If x is of type "mask" the discrete raster approximation of the window is displayed as a binary image (white inside the window, black outside).

Graphical parameters controlling the display (e.g. setting the colours) may be passed directly via the ... arguments, or indirectly reset using spatstat.options.

When x is of type "rectangle" or "polygonal", it is plotted by the Rfunction polygon. To control the appearance (colour, fill density, line density etc) of the polygon plot, determine the required argument of polygon and pass it through ... For example, to draw the polygon border in green, use the argument border="green".

When x is of type "mask", it is plotted by image.default. The appearance of the image plot can be controlled by passing arguments to image.default through .... The default appearance can also be changed by setting the parameter par.binary of spatstat.options.

See Also

owin.object, plot.ppp, polygon, image.default, spatstat.options

Examples

# rectangular window
   data(nztrees)
   plot(nztrees$window)
   abline(v=148, lty=2)

  # polygonal window
  plot(c(0,1),c(0,1),type="n")
  bdry <- locator()
  # click the vertices of a polygon (anticlockwise)
  w <- owin(c(0,1), c(0,1), poly=bdry)
  plot(w)

  # binary mask
  we <- erode.owin(w, 0.05, FALSE)
  plot(we)
  spatstat.options(par.binary=list(col=grey(c(0.5,1))))
  plot(we)