LTPDA Toolbox™ contents FIR Filters   Applying digital filters to data

Filter banks

Description Constructor description.
Create Creating a filter bank in the LTPDA.
From plist Creating from a plist.
From filters Creating from filter objects.
Import Importing an existing filterbank.

Description

A filter bank is a container object for collections of MIIR and MFIR filters. The filter bank object can be used to filter a discrete data series in parallel or in series, in accordance to the schematic representations of figures 1 and 2.

Figure 1: Scheme for parallel filtering. Data is input to the different filters of the bank. Filters output are summed each other in order to obtain the complete output. The different filters of the bank must have the same input and output units.

Figure 2: Scheme for serial filtering. The output of each filter is input to the following filter till the end of the series.

Creating a filter bank in the LTPDA

The LTPDA Toolbox allows the implementation of filter banks by means of the filterbank class.

Creating from a plist

The following example creates a parallel filter bank of MIIR filters. 

    
    iirhp = miir(plist('type', 'highpass'));
    iirlp = miir(plist('type', 'lowpass'));
    pl = plist('filters', [iirhp iirlp], ...
      'type', 'parallel');
    f = filterbank(pl)

The following example creates a serial filter bank of MIIR filters. 

    
    iirhp = miir(plist('type', 'highpass'));
    iirlp = miir(plist('type', 'lowpass'));
    pl = plist('filters', [iirhp iirlp], ...
      'type', 'series');
    f = filterbank(pl)

Creating from filter objects

The following example creates a parallel filter bank of MIIR filters. 

    
    iirhp = miir(plist('type', 'highpass'));
    iirlp = miir(plist('type', 'lowpass'));
    pl = plist('type', 'parallel');
    f = filterbank(iirhp,iirlp,pl)

The following example creates a serial filter bank of MIIR filters. 

    
    iirhp = miir(plist('type', 'highpass'));
    iirlp = miir(plist('type', 'lowpass'));
    pl = plist('type', 'series');
    f = filterbank(iirhp,iirlp,pl)

Importing an existing model

The filterbank constructor also accepts as an input existing models in different formats:

  • XML files:

        f = filterbank('foo_filterbank.xml')

  • MAT files:

        f = filterbank('foo_filterbank.mat')

  • From repository:

        f = filterbank(plist('hostname', 'localhost', 'database', 'ltpda', 'ID', []))


    • FIR Filters  FIR Filters   Applying digital filters to data Applying digital filters to data

    ©LTP Team