Accelerating the pace of engineering and science

# Documentation Center

• Trials
• Product Updates

# wpjoin

Recompose wavelet packet

## Syntax

T = wpjoin(T,N)
[T,X] = wpjoin(T,N)
T = wpjoin(T)
T = wpjoin(T,0)
[T,X] = wpjoin(T)
[T,X] = wpjoin(T,0)

## Description

wpjoin is a one- or two-dimensional wavelet packet analysis function.

wpjoin updates the wavelet packet tree after the recomposition of a node.

The nodes are numbered from left to right and from top to bottom. The root index is 0.

T = wpjoin(T,N) returns the modified wavelet packet tree T corresponding to a recomposition of the node N.

[T,X] = wpjoin(T,N) also returns the coefficients of the node.

T = wpjoin(T) is equivalent to T = wpjoin(T,0).

[T,X] = wpjoin(T) is equivalent to [T,X] = wpjoin(T,0).

## Examples

```% The current extension mode is zero-padding (see dwtmode).

% Load signal.
load noisdopp; x = noisdopp;

% Decompose x at depth 3 with db1 wavelet packets.
wpt = wpdec(x,3,'db1');

% Plot wavelet packet tree wpt.
plot(wpt)
```

```% Recompose packet (1,1) or 2
wpt = wpjoin(wpt,[1 1]);

% Plot wavelet packet tree wpt.
plot(wpt)
```

## See Also

Was this topic helpful?