isfir

Determine if digital filter has finite impulse response

Syntax

Description

example

flag = isfir(d) returns true if a digital filter, d, has a finite impulse response.

Examples

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FIR and IIR Digital Filters

Use designfilt to design FIR and IIR versions of a highpass filter. Specify a normalized stopband frequency of 0.3 and a normalized passband frequency of 0.6. Verify that each filter is of the correct class. Display the frequency responses of the filters.

fir = designfilt('highpassfir','StopbandFrequency',0.3,'PassbandFrequency',0.6);
iir = designfilt('highpassiir','StopbandFrequency',0.3,'PassbandFrequency',0.6);
isfirFIR = isfir(fir)
isiirFIR = isfir(iir)
fvt = fvtool(fir,iir);
legend(fvt,'FIR','IIR')
isfirFIR =

     1


isiirFIR =

     0

Input Arguments

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d — Digital filterdigitalFilter object

Digital filter, specified as a digitalFilter object. Use designfilt to generate a digital filter based on frequency-response specifications.

Example: d = designfilt('lowpassiir','FilterOrder',3,'HalfPowerFrequency',0.5) specifies a third-order Butterworth filter with normalized 3-dB frequency 0.5π rad/sample.

Output Arguments

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flag — Filter class identificationlogical scalar

Filter class identification, returned as a logical scalar.

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