spatstat (version 1.42-2)

affine.owin: Apply Affine Transformation To Window

Description

Applies any affine transformation of the plane (linear transformation plus vector shift) to a window.

Usage

## S3 method for class 'owin':
affine(X, mat=diag(c(1,1)), vec=c(0,0), ..., rescue=TRUE)

Arguments

X
Window (object of class "owin").
mat
Matrix representing a linear transformation.
vec
Vector of length 2 representing a translation.
rescue
Logical. If TRUE, the transformed window will be processed by rescue.rectangle.
...
Optional arguments passed to as.mask controlling the pixel resolution of the transformed window, if X is a binary pixel mask.

Value

  • Another window (of class "owin") representing the result of applying the affine transformation.

Details

The window is subjected first to the linear transformation represented by mat (multiplying on the left by mat), and then the result is translated by the vector vec. The argument mat must be a nonsingular $2 \times 2$ matrix.

This is a method for the generic function affine.

See Also

affine, affine.ppp, affine.psp, affine.im, rotate, shift

Examples

Run this code
# shear transformation
  shear <- matrix(c(1,0,0.6,1),ncol=2)
  X <- affine(owin(), shear)
  plot(X)
  data(letterR)
  affine(letterR, shear, c(0, 0.5))
  affine(as.mask(letterR), shear, c(0, 0.5))

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