Digital Filter Analysis

Magnitude, phase, impulse, and step responses, phase and group delays, pole-zero analysis

Analyze frequency- and time-domain responses of filters. Visualize filter poles and zeros in the complex plane.


abs Absolute value (magnitude)
angle Phase angle
freqz Frequency response of digital filter
grpdelay Average filter delay (group delay)
phasedelay Phase delay of digital filter
phasez Phase response of digital filter
unwrap Correct phase angles to produce smoother phase plots
zerophase Zero-phase response of digital filter
zplane Zero-pole plot
impz Impulse response of digital filter
impzlength Impulse response length
stepz Step response of digital filter
fdatool Open Filter Design and Analysis Tool
fvtool Open Filter Visualization Tool
sptool Open interactive digital signal processing tool
filtord Filter order
filternorm 2-norm or infinity-norm of digital filter
firtype Type of linear phase FIR filter
isallpass Determine whether filter is allpass
isfir Determine if digital filter has finite impulse response
islinphase Determine whether filter has linear phase
ismaxphase Determine whether filter is maximum phase
isminphase Determine whether filter is minimum phase
isstable Determine whether filter is stable

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