R: Randomly Shift a List of Point Patterns

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, ..., which=seq_along(X))

### Arguments

`X` | An object of class `"splitppp"`. Basically a list of point patterns.
`...` | Parameters controlling the generation of the random shift vector and the handling of edge effects. See `rshift.ppp`.
`which` | Optional. Identifies which patterns will be shifted, while other patterns are not shifted. Any valid subset index for `X`.

### 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.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### 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 1.54-0 Index]