Converting models to digital filters

Transfer functions models can be converted to IIR/FIR filters using the bilinear transform. The result of the conversion is an miir/mfit object. To convert a model, you need simply to input your model into the miir/mfir constructor. In the current LTPDA version, only the following discretization from transfer function models are allowed:

Pole/zero model TF

From pzmodel

To get an IIR filter from a given pzmodel we need to write down
    >> filt = miir(pzmodel)

If no sample rate is specified, then the conversion is done for a sample rate equal to 8 times the highest pole or zero frequency. You can set the sample rate by specifying it in the parameter list:

    >> filt = miir(pzmodel,plist('fs', 1000))

For more information of IIR filters in LTPDA, see IIR Filters.

From partial fraction

Analogously, the same rules apply to a partial fraction model parfrac constructor
    >> filt = miir(parfrac)

©LTP Team