accessD.wpst {wavethresh}

Get coefficients from a non-decimated wavelet packet object (wpst) in time order.

Description

The coefficients from a non-decimated wavelet packet object, wpst, are stored in a particular order in the wpst component of the wpstobj object. This function extracts all the coefficients corresponding to a particular wavelet packet in time order.

Usage

## S3 method for class 'wpst'
accessD(wpst, level, index, ...)

Arguments

wpst

Non-decimated wavelet packet object from which you wish to extract time-ordered coefficients.

level

The resolution level that you wish to extract. This can range from zero (the coarsest coefficients) to nlevelsWT-1(wstobj) which are the finest scale coefficients.

index

The wavelet packet index that you require (sequency ordering). This can range from 0 (father wavelet coeffcients) to 2^(nlevelsWT - level) - 1, i.e. the maximum is dependent on the resolution level.

...

any other arguments

Details

The wpst function performs a non-decimated wavelet packet transform. This function extracts the coefficients at a particular resolution level specified by level in time order.

It is possible to extract the individual packets (before interweaving, i.e. the direct result of multiple applications of the packet operators) by using the getpacket.wpst function.

Author(s)

G P Nason

References

Nason, G.P., Sapatinas, T. and Sawczenko, A. Statistical modelling using undecimated wavelet transforms.

See Also

wpst, wpst.object, accessD, getpacket.wpst

Examples

#
# Get the 4th level of coefficients from a decomposition
#
dat <- rnorm(128)
accessD(wpst(dat), level=4, index=3)