PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

DTFT, DFT, ZT, and FFT 529

0 5 10 15

− 2

− 1

0

angle [DFT[fn(n)]]

1

2

frequency W in rad.

0 5 10 15

0

20

abs [DFT[f(n)]]

40

60

frequency W in rad.

DFT[f1(n)] + DFT[f2(n)] + DFT[f3(n)] versus W

FIGURE 5.42

Plots of magnitude and phase angle of the sums of DFT of f 1 (n), f 2 (n), and f 3 (n) of Example 5.9.

FIGURE 5.41

Plots of angleDFT of f 1 (n), f 2 (n), and f 3 (n) of Example 5.9.

0 5

0.5

0

− 1

−0.5

2

0

angle [DFT[f3(n)]]

angle [DFT[f2(n)]]

angle [DFT[f1(n)]]

− 2

0

1

(^1015)
015 015
015 0
frequency W in rad.
15
W
W
[Phases of the DFTs of f1(n), f2(n) & f3(n)] versus W