## Description

example

value = read(T,propname,propparam) returns the value of the wavelet packet tree T property specified by propname. propparam is an optional parameter depending on the value of propname.

You can specify one or more properties in any order. propname-propparam arguments must appear after other arguments. For example, [value1,value2,value3,value4] = read(T,propname1,propname2,propname3,propparam3,propname4,propparam4).

## Examples

collapse all

Create a wavelet packet tree.

x = rand(1,512);
t = wpdec(x,3,"db3");
t = wpjoin(t,[4;5]);

Display the tree.

plot(t)

Obtain the size of the data at every node in ascending node index order.

sAll = 11×2

1   512
1   258
1   258
1   131
1   131
1   131
1   131
1    68
1    68
1    68
⋮

Obtain the size of the data at nodes of indices 0, 4 and 5.

sNod = 3×2

1   512
1   131
1   131

Obtain the entropy of all the nodes.

eAll = 11×1

116.3597
45.9147
39.1646
-30.2074
17.6607
20.8560
18.8364
-114.8913
11.4664
9.2578
⋮

Obtain the entropy at nodes of indices 0, 4 and 5.

eNod = 3×1

116.3597
17.6607
20.8560

Obtain the wavelet filters and wavelet coefficients.

[max(abs(loD-loD1)) max(abs(hiD-hiD1)) ...
max(abs(loR-loR1)) max(abs(hiR-hiR1))]
ans = 1×4

0     0     0     0

Obtain the wavelet coefficients at all nodes.

Obtain the wavelet coefficients at nodes of indices 4 and 5.

[max(abs(dNod{1}-cfs4)) max(abs(dNod{2}-cfs5))]
ans = 1×2

0     0

Plot the coefficients at node index 4.

plot(cfs4)
title("Node 4 Wavelet Coefficients")

## Input Arguments

collapse all

Wavelet packet tree, specified as a WPTREE object.

Wavelet packet tree property name, specified as one of the following:

Property Name (propname)

Property Parameter (propparam)

"ent", "ento" or "sizes" (see wptree)

Without propparam or with propparam = Vector of node indices, value contains the entropy (or optimal entropy, or size) of the tree nodes in ascending node index order.

"cfs"

With propparam = One terminal node index. value = read(T,"cfs",NODE) is equivalent to value = read(T,"data",NODE) and returns the coefficients of the terminal node NODE.

"entName", "entPar", "wavName" (see wptree) or "allcfs"

Without propparam. value = read(T,"allcfs") is equivalent to value = read(T,"data"). value contains the desired information in ascending node index order of the tree nodes.

"wfilters" (see wfilters)

Without propparam or with propparam = "d","r","l","h".

"data"

Without propparam or with propparam = One terminal node index or propparam = Column vector of terminal node indices. In this last case, value is a cell array. Without propparam, value contains the coefficients of the tree nodes in ascending node index order.