www.gusucode.com > signal 案例源码程序 matlab代码 > signal/StepResponseOfAButterworthFilterstepzExample.m

    %% Step Response of a Butterworth Filter
% Create a third-order Butterworth filter with normalized half-power
% frequency $0.4\pi$ rad/sample. Display its step response.

% Copyright 2015 The MathWorks, Inc.


%%

[b,a] = butter(3,0.4);
stepz(b,a)
grid

%%
% Create an identical filter using |designfilt| and display its step
% response using |fvtool|.

d = designfilt('lowpassiir','FilterOrder',3,'HalfPowerFrequency',0.4);
stepz(d)