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)