# dsp.DyadicAnalysisFilterBank

Dyadic analysis filter bank

## Description

The `dsp.DyadicAnalysisFilterBank`

System object™ decomposes a broadband signal into a collection of subbands with smaller
bandwidths and slower sample rates. The System object uses a series of highpass and lowpass FIR filters to provide approximate octave
band frequency decompositions of the input. Each filter output is downsampled by a factor of
two. With the appropriate analysis filters and tree structure, the dyadic analysis filter bank
is a discrete wavelet transform (DWT) or discrete wavelet packet transform (DWPT).

To obtain approximate octave band frequency decompositions of the input:

Create the

`dsp.DyadicAnalysisFilterBank`

object and set its properties.Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

## Creation

### Description

constructs a dyadic analysis filter bank object, `dydan`

= dsp.DyadicAnalysisFilterBank`dydan`

, that computes
the level-two discrete wavelet transform (DWT) of a column vector input. For a 2-D matrix
input, the object transforms the columns using the Daubechies third-order extremal phase
wavelet. The length of the input along the first dimension must be a multiple of 4.

`dydan = dsp.DyadicAnalysisFilterBank(`

returns a dyadic analysis filter bank object, with each property set to the specified
value.`Name,Value`

)

## Properties

## Usage

### Syntax

### Description

### Input Arguments

### Output Arguments

## Object Functions

To use an object function, specify the
System object as the first input argument. For
example, to release system resources of a System object named `obj`

, use
this syntax:

release(obj)

## Examples

## Algorithms

This object implements the algorithm, inputs, and outputs described on the Dyadic Analysis Filter Bank block reference page. The object properties correspond to the block parameters, except:

The dyadic analysis filter bank object always concatenates the subbands into a
single column vector for a column vector input, or into the columns of a matrix for a
matrix input. This behavior corresponds to the block's behavior when you set the
Output parameter to ```
Single
port
``` . |

## Version History

**Introduced in R2012a**