PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

DTFT, DFT, ZT, and FFT 507

0.5

1

1.5

2

2.5

DTFT [0.6n u(n)] using freqz

Magnitude

− 4 − 3 − 2 − 1 0 1 2 3 4

− 1

−0.5

0

0.5

1

frequency W in rad.

− 4 − 3 − 2 −1 0123 4

frequency W in rad.

Phase in rad.

FIGURE 5.19

DTFT of f(n) using freqz of Example 5.1.

FIGURE 5.20

Error evaluation (parts b and c) of Example 5.1.

0

5

10

Magnitude error

Amplitude

− 4 − 3 − 2 − 1 0 1 2 3 4

− 4 − 3 − 2 − 101234

− 2

− 1

− 5

0

1

2

× 10 −^16

× 10 −^16

frequency W in rad.

Phase error

Phase in rad.