write

Write values in WPTREE fields

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    Syntax

    T = write(T,"cfs",node,coefs)

    Description

    T = write(T,"cfs",node,coefs) writes coefficients coefs for the terminal node node.

    You can specify one or more pairs of nodes and coefficients in any order. For example, T = write(T,"cfs",node1,coefs1,"cfs",node2,coefs2,"cfs",node3,coefs3).

    example

    Examples

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    Open Live Script

    Load a signal. Create a wavelet packet tree.

    load wecg
x = wecg;
t = wpdec(x,3,"db3");
t = wpjoin(t,[4;5]);

    Plot the tree.

    plot(t)

    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.

    The terminal nodes at (2,1), (2,2), and (3,0) have indices 4, 5, and 7, respectively. The terminal node (3,0) corresponds to filtering the signal at the lowest frequency subband. Set the coefficients at the three nodes to 0.

    sNod = read(t,"sizes",[4,5,7]);  
cfs4 = zeros(sNod(1,:));
cfs5 = zeros(sNod(2,:));
cfs7 = zeros(sNod(3,:));
t = write(t,"cfs",4,cfs4,"cfs",5,cfs5,"cfs",7,cfs7);

    Plot the tree again, and view the data at the root node. The plot shows the reconstruction of the signal after setting the coefficients at the three terminal nodes to 0.

    plot(t)

    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.

    Input Arguments

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    Wavelet packet tree, specified as a wptree object.

    Terminal node index, specified as an integer.

    Coefficients to write for the terminal node, specified as a vector.

    The vector must have the correct size for the specified terminal node. You can use s = read(T,"sizes",node) to obtain the correct size. To obtain the sizes of multiple terminal nodes, use s = read(T,"sizes",[node1;node2;…]), where node1, node2, …, are the node indices.

    Version History

    Introduced before R2006a

    See Also

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