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accessD.wpst
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
accessD.wpst(wpstobj, level, index)
REQUIRED ARGUMENTS
- wpstobj
- 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
nlevels-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^(nlevels - level) - 1, i.e. the maximum is dependent on
the resolution level.
OPTIONAL ARGUMENTS
None.
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.
Nason, G.P., Sapatinas, T. and Sawczenko, A.
Statistical modelling using
undecimated wavelet transforms.
SEE ALSO
wpst,
wpstobj,
accessD,
getpacket.wpst,
EXAMPLES
#
# Get the 4th level of coefficients from a decomposition
#
> accessD(wpst(data), level=4)