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wptree

WPTREE constructor

    Description

    example

    T = wptree(order,depth,x,wname) returns a complete wavelet packet tree T of order order corresponding to a wavelet packet decomposition of x at level depth, using Shannon entropy and the wavelet specified by wname.

    T = wptree(order,depth,x,wname) is equivalent to T = wptree(order,depth,x,wname,'shannon').

    T = wptree(order,depth,x,wname,enttype,entpar) uses the entropy type specified by enttype. entpar is an optional parameter depending on the value of enttype.

    T = wptree(order,depth,x,wname,enttype,entpar,userdata) sets the userdata field of T.

    Examples

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    Create a 1-D signal.

    x = rand(1,512);

    Create the wavelet packet decomposition tree associated with the wavelet packet decomposition of the signal at level 3 using the db3 wavelet.

    t = wptree(2,3,x,"db3");

    Recompose the fourth and fifth nodes of the tree. Plot the result.

    t = wpjoin(t,[4;5]);
    plot(t)

    {"String":"Figure contains 2 axes objects and other objects of type uimenu. Axes object 1 with title Tree Decomposition contains 21 objects of type line, text. Axes object 2 with title data for node: 0 or (0,0). contains an object of type line.","Tex":["Tree Decomposition","data for node: 0 or (0,0)."],"LaTex":[]}

    Click the node (3,0) to get this figure:

    node30.png

    Input Arguments

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    Order of the tree, specified as 2 or 4. The order of the tree is the number of children of each nonterminal node. If x is a vector (1-D signal), specify an order of 2. If x is a matrix (image), specify an order of 4.

    Data Types: double

    Level of wavelet packet decomposition, specified as a positive integer.

    Data Types: double

    Input data, specified as a vector (signal) or matrix (image).

    Data Types: double

    Wavelet name, specified as a character vector or string scalar. For more information, see wfilters.

    Data Types: string | char

    Entropy type, specified as a character vector or string scalar. For more information, see wentropy, wpdec, or wpdec2

    Data Types: string | char

    Optional parameter used for entropy computation. For more information, see wentropy, wpdec, or wpdec2.

    Data Types: double | string | char

    User data to set in the userdata field of T, specified as an array, cell array, or structure array.

    Example: t = wptree(2,3,x,'db3','sure',0.5,{1,"aa",rand(3,3)})

    Output Arguments

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    Wavelet packet tree, returned as a WPTREE object.

    • If order = 2, T is a WPTREE object corresponding to a wavelet packet decomposition of the vector (signal) x, at level depth with a particular wavelet wname.

    • If order = 4, T is a WPTREE object corresponding to a wavelet packet decomposition of the matrix (image) x, at level depth with a particular wavelet wname.

    The WPTREE object has these fields:

    'dtree'DTREE parent object
    'wavInfo'Structure (wavelet information)
    'entInfo'Structure (entropy information)

    For more information on object fields, see the get function or type

    help wptree/get
    

    The wavelet information structure, 'wavInfo', contains

    'wavName'Wavelet name
    'Lo_D'Low Decomposition filter
    'Hi_D'High Decomposition filter
    'Lo_R'Low Reconstruction filter
    'Hi_R'High Reconstruction filter

    The entropy information structure, 'entInfo', contains

    'entName'Entropy name
    'entPar'Entropy parameter

    Fields from the DTREE parent object:

    'allNI'

    All nodes information

    'allNI' is an array of size nbnode by 5, which contains

    indIndex
    sizeSize of data
    entEntropy
    entoOptimal entropy

    Each line is built based on this scheme:

    Version History

    Introduced before R2006a

    See Also

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