rshift.splitppp {spatstat}R Documentation

Randomly Shift a List of Point Patterns

Description

Randomly shifts each point pattern in a list of point patterns.

Usage

   ## S3 method for class 'splitppp':
   rshift(X, ..., radius, width, height, edge="torus", clip,
                        which)
                        

Arguments

X An object of class "splitppp". Basically a list of point patterns.
... Ignored.
radius,width,height Optional parameters controlling the generation of the random shift vector. See Details.
edge String indicating how to deal with edges of the patterns. Options are "torus", "erode" and "none". See Details.
which Optional. Identifies which patterns will be shifted, while other patterns are not shifted. Any valid subset index for X.
clip Optional. Window to which the final point patterns should be clipped.

Details

This operation applies a random shift to each of the point patterns in the list X.

The function rshift is generic. This function rshift.splitppp is the method for objects of class "splitppp", which are essentially lists of point patterns, created by the function split.ppp.

By default, every pattern in the list X will be shifted. The argument which indicates that only some of the patterns should be shifted, while other groups should be left unchanged. which can be any valid subset index for X.

Each point pattern in the list X (or each pattern in X[which]) is shifted by a random displacement vector. The shifting is performed by rshift.ppp.

See the help page for rshift.ppp for details of the other arguments.

Value

Another object of class "splitppp".

Author(s)

Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf

See Also

rshift, rshift.ppp

Examples

   data(amacrine)
   Y <- split(amacrine)

   # random toroidal shift
   # shift "on" and "off" points separately
   X <- rshift(Y)

   # shift "on" points and leave "off" points fixed
   X <- rshift(Y, which="on")

   # maximum displacement distance 0.1 units
   X <- rshift(Y, radius=0.1)

   # shift with erosion
   X <- rshift(Y, radius=0.1, edge="erode")

[Package spatstat version 1.9-6 Index]