%% IIR Filter Effective Impulse Response Length — Coefficients
% Create a lowpass allpole IIR filter with a pole at 0.9. Calculate the effective impulse response length. Obtain the impulse response. Plot the result.

b = 1;
a = [1 -0.9];
len = impzlength(b,a)
[h,t] = impz(b,a);
stem(t,h)
h(len)

% Copyright 2012 The MathWorks, Inc.