spatstat.geom (version 3.2-8)

shift.psp: Apply Vector Translation To Line Segment Pattern

Description

Applies a vector shift to a line segment pattern.

Usage

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

Value

Another line segment pattern (of class "psp") representing the result of applying the vector shift.

Arguments

X

Line Segment pattern (object of class "psp").

vec

Vector of length 2 representing a translation.

...

Ignored

origin

Location that will be shifted to the origin. Either a numeric vector of length 2 giving the location, or a point pattern containing only one point, or a list with two entries named x and y, or one of the character strings "centroid", "midpoint", "left", "right", "top", "bottom", "topleft", "bottomleft", "topright" or "bottomright" (partially matched).

Author

Adrian Baddeley

and Rolf Turner

Details

The line segment pattern, and its window, are translated by the vector vec.

This is a method for the generic function shift.

If origin is given, the argument vec will be ignored; instead the shift will be performed so that the specified geometric location is shifted to the coordinate origin \((0,0)\). The argument origin should be either a numeric vector of length 2 giving the spatial coordinates of a location, or one of the character strings "centroid", "midpoint", "left", "right", "top", "bottom", "topleft", "bottomleft", "topright" or "bottomright" (partially matched). 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, and so on.

See Also

shift, shift.owin, shift.ppp, periodify, rotate, affine

Examples

  X <- psp(runif(10), runif(10), runif(10), runif(10), window=owin())
  plot(X, col="red")
  Y <- shift(X, c(0.05,0.05))
  plot(Y, add=TRUE, col="blue")

  shift(Y, origin="mid")