Applies any affine transformation of the plane (linear transformation
plus vector shift) to a plane geometrical object,
such as a point pattern or a window.
Usage
affine(X, mat=diag(c(1,1)), vec=c(0,0))
Arguments
X
Any suitable dataset representing a two-dimensional
object, such as a point pattern (object of class "ppp"),
or a window (object of class "owin").
mat
Matrix representing a linear transformation.
vec
Vector of length 2 representing a translation.
Value
Another object of the same type, representing the
result of applying the affine transformation.
synopsis
affine(X, ...)
Details
This is generic. Methods are provided for
point patterns (affine.ppp)
and windows (affine.owin).
First the linear transformation represented by
mat is applied (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.