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Impulse Response

The impulse response of a digital filter is the output arising from the unit impulse sequence defined as

δ(n)={1,n=0,0,n0.

You can generate an impulse sequence a number of ways; one straightforward way is

imp = [1; zeros(50,1)];

The impulse response of the simple filter with b=1 and a=[1-0.9] is h(n)=0.9n, which decays exponentially.

b = 1;
a = [1 -0.9];

h = filter(b,a,imp);

stem(0:50,h)

A simple way to display the impulse response is with the impz function.

impz(b,a,51)

See Also

Functions