trans2d: 2D Spatial Transformation

In kuwisdelu/matter: Out-of-core statistical computing and signal processing

2D Spatial Transformation

Description

Perform linear spatial transformations on a matrix, including rigid, similarity, and affine transformations.

Usage

trans2d(x, y, z, pmat,
	rotate = 0, translate = c(0, 0), scale = c(1, 1),
	interp = "linear", dimout = dim(z), ...)

Arguments

x, y, z	The data to be interpolated. Alternatively, x can be a matrix, in which case the matrix elements are used for z and x and y are generated from the matrix's dimensions.
pmat	A 3 x 2 transformation matrix for performing an affine transformation. Automatically generated from rotate, translate, and scale if not provided.
rotate	Rotation in degrees.
translate	Translation vector, in the same units as x and y, if given.
scale	Scaling factors.
interp	Interpolation method. See approx2.
dimout	The dimensions of the returned matrix.
...	Additional arguments passed to approx2.

Value

If x is a matrix or z is provided, returns a transformed matrix with the dimensions of dimout.

Otherwise, only the transformed coordinates are returned in a data.frame.

Author(s)

Kylie A. Bemis

See Also

approx2

Examples

set.seed(1)
x <- matrix(0, nrow=32, ncol=32)
x[9:24,9:24] <- 10
x <- x + runif(length(x))
xt <- trans2d(x, rotate=15, translate=c(-5, 5))

par(mfcol=c(1,2))
image(x, col=hcl.colors(256), main="original")
image(xt, col=hcl.colors(256), main="transformed")

kuwisdelu/matter documentation built on Oct. 19, 2024, 10:31 a.m.