dwpt
Syntax
Description
returns the
terminal (final-level) nodes of the discrete wavelet packet transform (DWPT) of
wpt
= dwpt(X
)X
. The input X
is a real-valued vector, matrix,
or timetable. By default, the fk18
wavelet is used, and the decomposition
level is floor(log2(Ns))
, where
Ns is the number of data samples. The wavelet packet transform
wpt
is a 1-by-N cell array, where
N =
2^floor(log2(Ns))
.
[
also returns the transform levels of the nodes of wpt
,l
,packetlevels
] = dwpt(___)wpt
using any of the
previous syntaxes.
[
also returns the center frequencies of the approximate passbands in cycles per sample using
any of the previous syntaxes.wpt
,l
,packetlevels
,f
] = dwpt(___)
[
also returns the relative energy for the wavelet packets in wpt
,l
,packetlevels
,f
,re
] = dwpt(___)wpt
using
any of the previous syntaxes. The relative energy is the proportion of energy contained in
each wavelet packet by level.
[___] = dwpt(___,
specifies options using name-value pair arguments in addition to the input arguments in the
previous syntaxes. For example, Name,Value
)'Level',4
specifies the decomposition
level.
Examples
Input Arguments
Output Arguments
More About
Algorithms
The dwpt
function performs a discrete wavelet packet transform and
produces a sequency-ordered wavelet packet tree. Compare the sequency-ordered and normal
(Paley)-ordered trees. is the scaling (lowpass) analysis filter, and represents the wavelet (highpass) analysis filter. The labels at the bottom
show the partition of the frequency axis [0, ½].
References
[1] Wickerhauser, Mladen Victor. Adapted Wavelet Analysis from Theory to Software. Wellesley, MA: A.K. Peters, 1994.
[2] Percival, D. B., and A. T. Walden. Wavelet Methods for Time Series Analysis. Cambridge, UK: Cambridge University Press, 2000.
[3] Mesa, Hector. “Adapted Wavelets for Pattern Detection.” In Progress in Pattern Recognition, Image Analysis and Applications, edited by Alberto Sanfeliu and Manuel Lazo Cortés, 3773:933–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. https://doi.org/10.1007/11578079_96.
Extended Capabilities
Version History
Introduced in R2020a