wavethresh (version 2.2-11)

compress.imwd: Compression and Decompression for `imwd' Objects

Description

Compresses or decompresses a (thresholded) imwd object (imwd.object) by removing or padding with zero elements.

Usage

## S3 method for class 'imwd':
compress(x, verbose = getOption("verbose"), ...)
## S3 method for class 'imwdc':
uncompress(x, verbose = getOption("verbose"), ...)

Arguments

x

class imwd object to compress or class imwdc to decompress.

verbose

logical; if true then report on compression activity.

...

further arguments to be passed to or from methods.

Value

• An object of class "imwdc" representing the compressed imwd object, see imwdc.object.

RELEASE

Release 2.2 Copyright Guy Nason 1993

Details

Thresholded imwd objects are usually very large and contain many zero elements. This function compresses these objects into smaller "imwdc" objects by using the compress.default function and removing the zeroes.

compress.imwd is a method for the generic function compress for class imwd. The user shouldn't need to use this function directly.

uncompress.imwd uncompresses a imwdc object back into a imwd one. It is a method for the generic function uncompress() for class imwdc. It can be invoked by calling uncompress(x) for an object x of the appropriate class, or directly by calling uncompress.imwdc(x) regardless of the class of the object.

See Also

compress.default, uncompress.default, threshold, imwd.object,imwdc.object.

Examples

data(lennon)
imwdL <- imwd(lennon)

cwd <- compress(imwdL)
uwd <- uncompress(cwd)
stopifnot(identical(sort(names(uwd)), sort(N <- names(imwdL))),
          all.equal(uwd[N], imwdL[N], tol = 1e-15))