grow.rectangle {spatstat.geom}

Add margins to rectangle

Description

Adds a margin to a rectangle.

Usage

 grow.rectangle(W, xmargin=0, ymargin=xmargin, fraction=NULL)

Arguments

W

A window (object of class "owin"). Must be of type "rectangle".

xmargin

Width of horizontal margin to be added. A single nonnegative number, or a vector of length 2 indicating margins of unequal width at left and right.

ymargin

Height of vertical margin to be added. A single nonnegative number, or a vector of length 2 indicating margins of unequal width at bottom and top.

fraction

Fraction of width and height to be added. A number greater than zero, or a numeric vector of length 2 indicating different fractions of width and of height, respectively. Incompatible with specifying xmargin and ymargin.

Details

This is a simple convenience function to add a margin of specified width and height on each side of a rectangular window. Unequal margins can also be added.

Value

Another object of class "owin" representing the window after margins are added.

Author(s)

Adrian Baddeley [e-mail], Rolf Turner [e-mail] and Ege Rubak [e-mail].

See Also

trim.rectangle, dilation, erosion, owin.object

Examples

  w <- square(10)
  # add a margin of width 1 on all four sides
  square12 <- grow.rectangle(w, 1)

  # add margin of width 3 on the right side
  # and margin of height 4 on top.
  v <- grow.rectangle(w, c(0,3), c(0,4))

  # grow by 5 percent on all sides
  grow.rectangle(w, fraction=0.05)