issos

Verify if discrete-time System object filter is in second-order sections form

Syntax

flag = issos(sysobj)

Description

flag = issos(sysobj) determines whether the filter System object™ is in second-order sections (SOS) form, returning a logical 1 if true and a logical 0 if false.

Examples

Design Lowpass SOS Filter

By default, fdesign and design functions return SOS filters when possible. This example designs a lowpass SOS filter that uses fixed-point arithmetic.

d = fdesign.lowpass('n,fp,ap,ast',40,0.55,0.1,60);
hd = design(d,'ellip','SystemObject',true);

Using the issos function, verify whether the designed filter is in SOS form.

IsSOS = issos(hd)

IsSOS = logical
   1

The filter is in second-order section form.

Input Arguments

sysobj — Input filter

filter System object

Input filter, specified as one of the following filter System objects:

• dsp.AllpassFilter

• dsp.AllpoleFilter

• dsp.BiquadFilter

• dsp.CICCompensationDecimator

• dsp.CICCompensationInterpolator

• dsp.CICDecimator

• dsp.CICInterpolator

• dsp.CoupledAllpassFilter

• dsp.Differentiator

• dsp.FarrowRateConverter

• dsp.FilterCascade

• dsp.FIRDecimator

• dsp.FIRFilter

• dsp.FIRHalfbandDecimator

• dsp.FIRHalfbandInterpolator

• dsp.FIRInterpolator

• dsp.FIRRateConverter

• dsp.FourthOrderSectionFilter

• dsp.HighpassFilter

• dsp.IIRFilter

• dsp.IIRHalfbandDecimator

• dsp.IIRHalfbandInterpolator

• dsp.LowpassFilter

• dsp.NotchPeakFilter

• dsp.SOSFilter

• dsp.VariableBandwidthFIRFilter

• dsp.VariableBandwidthIIRFilter

Output Arguments

flag — Flag to determine if filter is in SOS form

1 | 0

Flag to determine whether the filter is in second-order sections (SOS) form, returned as a logical scalar. If the filter is in SOS form, issos returns a logical 1, else it returns a logical 0.

Data Types: logical

Version History

Introduced in R2011a