| affine {spatstat} | R Documentation |
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.
affine(X, mat=diag(c(1,1)), vec=c(0,0))
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. |
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 * 2
matrix.
Another object of the same type, representing the result of applying the affine transformation.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
affine.ppp,
affine.owin,
rotate,
shift
data(cells) # shear transformation X <- affine(cells, matrix(c(1,0,0.6,1),ncol=2)) ## Not run: plot(X) # rescale y coordinates by factor 1.3 plot(affine(cells, diag(c(1,1.3)))) ## End(Not run)