Converting the Filter Structure :: FDATool: A Filter Design and Analysis GUI (Signal Processing Toolbox)

Signal Processing Toolbox

Converting the Filter Structure

Converting to a New Structure

You can use Edit->Convert Structure to convert the current filter to a new structure. All filters can be converted to the following representations:

Direct-form I
Direct-form II
Direct-form I transposed
Direct-form II transposed
Lattice ARMA

Note If you have installed the Filter Design Toolbox you will see additional structures in the Convert structure dialog box.

In addition, the following conversions are available for particular classes of filters:

Minimum phase FIR filters can be converted to Lattice minimum phase
Maximum phase FIR filters can be converted to Lattice maximum phase
Allpass filters can be converted to Lattice allpass
IIR filters can be converted to Lattice ARMA

Note Converting from one filter structure to another may produce a result with different characteristics than the original. This is due to the computer's finite-precision arithmetic and the variations in the conversion's round-off computations.

For example:

Select Convert Structure from the Edit menu to open the Convert structure dialog box.
Select Direct-form I in the list of filter structures.

Editing the Filter Using the Pole/Zero Editor Converting to Second-Order Sections