The resample function uses a kernel function to resample a target
array. This can be thought of as a generalisation of array indexing which
allows fractional indices. It is (S3) generic. The rescale function
is an alternative interface for the common case where the image is being
scaled to a new size.
resample(x, points, kernel, ...)
# S3 method for default
resample(x, points, kernel, pointType = c("auto", "general", "grid"), ...)
rescale(x, factor, kernel, ...)| x | Any object. For the default method, this must be coercible to an array. |
|---|---|
| points | Either a matrix giving the points to sample at, one per row, or a list giving the locations on each axis, which will be made into a grid. |
| kernel | A kernel function object, used to provide coefficients for each resampled value, or the name of one. |
| ... | Additional options, such as kernel parameters. |
| pointType | A string giving the type of the point specification being
used. Usually can be left as |
| factor | A vector of scale factors, which will be recycled to the
dimensionality of |
If a generalised sampling scheme is used (i.e. with points a
matrix), the result is a vector of sampled values. For a grid scheme (i.e.
with points a list, including for rescale), it is a
resampled array.
kernels for kernel-generating functions.
Jon Clayden <code@clayden.org>
resample(c(0,0,1,0,0), seq(0.75,5.25,0.5), triangleKernel())
#> [1] 0.00 0.00 0.00 0.25 0.75 0.75 0.25 0.00 0.00 0.00