R: Apply Vector Translation To Point Pattern

shift.ppp {spatstat} | R Documentation

## Apply Vector Translation To Point Pattern

### Description

Applies a vector shift to a point pattern.

### Usage

     ## S3 method for class 'ppp'
    shift(X, vec=c(0,0), ..., origin=NULL)

### Arguments

`X` | Point pattern (object of class `"ppp"`).
`vec` | Vector of length 2 representing a translation.
`...` | Ignored
`origin` | Character string determining a location that will be shifted to the origin. Options are `"centroid"`, `"midpoint"` and `"bottomleft"`. Partially matched.

### Details

The point pattern, and its window, are translated by the vector `vec`.

This is a method for the generic function `shift`.

If `origin` is given, then it should be one of the character strings `"centroid"`, `"midpoint"` or `"bottomleft"`. The argument `vec` will be ignored; instead the shift will be performed so that the specified geometric location is shifted to the origin. If `origin="centroid"` then the centroid of the window will be shifted to the origin. If `origin="midpoint"` then the centre of the bounding rectangle of the window will be shifted to the origin. If `origin="bottomleft"` then the bottom left corner of the bounding rectangle of the window will be shifted to the origin.

### Value

Another point pattern (of class `"ppp"`) representing the result of applying the vector shift.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

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

### See Also

`shift`, `shift.owin`, `periodify`, `rotate`, `affine`

### Examples

      data(cells)
      X <- shift(cells, c(2,3))
      ## Not run:
      plot(X)
      # no discernible difference except coordinates are different

    ## End(Not run)
      plot(cells, pch=16)
      plot(shift(cells, c(0.03,0.03)), add=TRUE)

      shift(cells, origin="mid")

[Package spatstat version 1.54-0 Index]