PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

92 Practical MATLAB® Applications for Engineers

axis([-15 15 -1.2 1.2]);

subplot(3,1,2);

plot(t, Hanwin);

axis([-15 15 -1.2 1.2]);

ylabel(‘Amplitude’);title(‘ [f(t)*Hanning widow] vs. t’);

subplot(3,1,3);

plot(t, Blackwin);

axis([-15 15 -1.2 1.2]);xlabel(‘t’);title(‘[f(t)*Blackman widow] vs.t’)

ylabel(‘Amplitude’)

figure(2)

subplot(2,2,1)

plot(t, Kaiwin);ylabel(‘Amplitude’)

title(‘[f(t)*Kaiser window] vs. t’)

axis([-10 10 -1.2 1.2]);

subplot(2,2,2)

plot(t,Triwin );ylabel(‘Amplitude’);

title(‘[f(t)*Triang. window] vs. t’);axis([-11 11 -1.2 1.2]);

subplot(2,2,3)

plot(t,Boxwin );

ylabel(‘Amplitude’);title(‘[f(t)*Boxcar window] vs. t’);

axis([-11 11 -1.2 1.2]);xlabel(‘t’)

subplot(2,2,4)

plot(t,Barwin );

ylabel(‘Amplitude’)

title(‘[f(t)*Barlett window] vs. t’)

axis([-11 11 -1.2 1.2]);xlabel(‘t’)

Back in the command window, the script fi le explore_window is executed and the results

are shown in Figures 1.77 and 1.78.

1

0

− 1

− 15 − 10 − 5 0 5 10 15

t

1

0

− 1

− 15 − 10 − 5 0 5 10 15

t

1

0

− 1

− 15 − 10 − 5 0 5 10 15

t

[f(t)*Hamming window] versus t

[f(t)*Hanning window] versus t

[f(t)*Blackman window] versus t

Amplitude

Amplitude

Amplitude

FIGURE 1.77
Plots of the windowed function f(t) using the Hamming, Hanning, and Blackman windows of Example 1.20.