isfir

Determine whether filter System object is FIR

Syntax

isfir(sysobj)


Description

isfir(sysobj) determines whether the filter System object™ sysobj is an FIR filter. If the filter is FIR, isfir returns 1.

To determine whether sysobj is an FIR filter, isfir(sysobj) inspects if the filter in the transfer function form has a scalar denominator. If it does, it is an FIR filter.

Examples

Determine Whether an FIR Filter

Design a Lowpass FIR Filter.

d = fdesign.lowpass;
h = design(d,'Systemobject',true)

h = 
  dsp.FIRFilter with properties:

            Structure: 'Direct form'
      NumeratorSource: 'Property'
            Numerator: [1x43 double]
    InitialConditions: 0

  Show all properties

Determine if the filter is an FIR filter using isfir.

isfir(h)

ans = logical
   1

isfir returns 1 to indicate that the filter is an FIR filter.