PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Time Domain Representation of Continuous and Discrete Signals 63

subplot(2,2,1);

stem (n, real(fn)); hold on; plot(n,yzero);

title (‘real part of [f(n)] vs. n’)

ylabel(‘real part of [f(n)]’);

axis([0 15 -2 3])

subplot(2,2,2);

stem(n, imag(fn));

hold on;plot(n,yzero);

ylabel(‘imaginary part of [f(n)]’)

title(‘imaginary part of [f(n)] vs. n’)

ylabel(‘imaginary part of [f(n)]’);

axis([0 15 -2 2])

subplot(2,2,3);

stem(n, abs(fn));

title(‘magnitude of [f(n)] vs. n’)

xlabel(‘time index n’)

ylabel(‘magnitude of [f(n)]’)

subplot(2,2,4);

stem(n,(180/pi) * angle(fn));

hold on; plot(n,yzero);

title(‘phase of [f(n)] vs n’)

xlabel(‘time index n’)

ylabel(‘degrees’)

The script fi le disc_plots is executed and the results are shown in Figure 1.54.

real part of [f(n)] versus n imaginary part of [f(n)] versus n

real part of [f(n)]

imaginary part of [f(n)]

3

2

1

− 1

− 2

0 51015

0

2

0

− 1

− 2

0 51015

1

magnitude of [f(n)] versus n

3

2

1

0

0 5 10 15

magnitude of [f(n)]

time index n time index n

degrees

200

100

− 100

− 200

0

0 5 10 15

phase of [f(n)] versus n

FIGURE 1.54

Plots of Example 1.6.