R: Wavelet Packet decomposition objects.

wp.object {wavethresh}

R Documentation

Wavelet Packet decomposition objects.

Description

These are objects of classes wp They represent a decomposition of a function with respect to a set of wavelet packet functions.

Details

To retain your sanity we recommend that wavelet packets be extracted in one of two ways:

use getpacket.wp to obtain individual packets.
use accessD.wp to obtain all coefficients at a particular resolution level.

You can obtain the coefficients directly from the wp$wp component but you have to understand their organization described above.

Value

The following components must be included in a legitimate ‘wp’ object.

`wp`	a matrix containing the wavelet packet coefficients. Each row of the matrix contains coefficients with respect to a particular resolution level. There are `nlevelsWT(wp)+1` rows in the matrix. Row `nlevels(wp)+1` (the “bottom”) row contains the “original” data used to produce the wavelet packet coefficients. Rows `nlevels`(wp) to row 1 contain coefficients at resolution levels `nlevels(wp)-1` to 0 (so the first row contains coefficients at resolution level 0). The columns contain the coefficients with respect to packets. A different packet length exists at each resolution level. The packet length at resolution level `i` is given by `2^i`. However, the `getpacket.wp` function should be used to access individual packets from a `wp` object.
`nlevelsWT`	The number of levels in the wavelet packet decomposition. If you raise 2 to the power of nlevels you get the number of data points used in the decomposition.
`filter`	a list containing the details of the filter that did the decomposition (equivalent to the return value from the `filter.select` function).
`date`	The date that the transform was performed or the wp was modified.

GENERATION

This class of objects is returned from the wp function to represent a wavelet packet decomposition of a function. Many other functions return an object of class wp.

METHODS

The wp class of objects has methods for the following generic functions: InvBasis, MaNoVe, accessC, accessD, basisplot, draw. getpacket, nlevelsWT, plot, print, putC, putD, putpacket, summary, threshold.

RELEASE

Author(s)

G P Nason