Time Domain Representation of Continuous and Discrete Signals 65
figure(2);
ut35 = stepfun(t, 2) - stepfun(t, 3);
f5 = f2.*ut35;
t _ 1 = t+1;
f8 = f4 + ut35;
subplot(2,2,1);
plot(t, f5);
axis([1 4 -.1 .2]);
title(‘f5(t) vs t,(Example 1.7)’);
ylabel(‘f5(t)’); grid
subplot(2,2,2);
plot(t, f1+f3); axis([-6 6 -.5 1.5]);
title(‘f6(t) vs t,(Example 1.7)’);
ylabel(‘f5(t)’);grid
subplot(2,2,3);
plot(t _ 1, f5); axis([2 4 -.1 .25]);
title(‘f7(t) vs t,(Example 1.7)’);
ylabel(‘f5(t)’); xlabel(‘t’);;grid
subplot(2,2,4);
plot(t, f8); axis([-6 6 -1.2 1]);
title(‘f8(t) vs t,(Example 1.7)’);
ylabel(‘f5(t)’);xlabel(‘t’); grid
The resulting plots are shown in Figures 1.55 and 1.56.
FIGURE 1.55
Plots of f 1 (t), f 2 (t), f 3 (t), and f 4 (t) of Example 1.7.
f1(t) versus t, (Example 1.7)
f3(t) versus t, (Example 1.7)
f2(t) versus t, (Example 1.7)
f4(t) versus t, (Example 1.7)
1
1
200
150
100
50
0
0.5
0.5
0.5
−0.5
−0.5
−0.5
0
0
0
f1(t)
f3(t)
f2(t)
f4(t)
− 5
− 5
0 − 5
0
5 0
5
5
5
− 1
− 5 0
t t