resample: Resample an array

Description Usage Arguments Value Author(s) See Also Examples

Description

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.

Usage

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resample(x, points, kernel, ...)

## Default S3 method:
resample(x, points, kernel, pointType = c("auto", "general",
  "grid"), ...)

rescale(x, factor, kernel, ...)

Arguments

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 "auto".

factor

A vector of scale factors, which will be recycled to the dimensionality of x.

Value

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.

Author(s)

Jon Clayden <[email protected]>

See Also

kernels for kernel-generating functions.

Examples

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resample(c(0,0,1,0,0), seq(0.75,5.25,0.5), triangleKernel())

Example output

 [1] 0.00 0.00 0.00 0.25 0.75 0.75 0.25 0.00 0.00 0.00

mmand documentation built on May 2, 2019, 6:53 a.m.