Time-Domain Analysis and z Transform - Introduction to Digital Signal Processing and Filter Design - page 90

To find the unit impulse response using the function impz ,weuse

b=[1];
a=[1 -0.4 -0.05];
[y,T]=impz(b,a,20)

and get

y = 1 . 0000

0 . 4000
0 . 2100
0 . 1040
0 . 0521
0 . 0260
0 . 0130
0 . 0065
0 . 0033
0 . 0016
0 . 0008
0 . 0004
0 . 0002
0 . 0001
0 . 0001
0 . 0000
0 . 0000
0 . 0000
0 . 0000
0 . 0000

Example 2.29

To get the same result, using the function filter ,weuse x =[1 zeros(1,
19)] which creates a vector [10000000000000000000] :

b=[1 0 0];
a=[1 -0.4 -0.05];