# rshift.splitppp

##### Randomly Shift a List of Point Patterns

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

##### Usage

```
## S3 method for class 'splitppp':
rshift(X, \dots, 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"`

.

##### See Also

##### 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")
```

*Documentation reproduced from package spatstat, version 1.41-1, License: GPL (>= 2)*