(b) a =-0.4; b = pi/6; c = a + b*i; K = -2.7; N =8; n = 1:N;
x = K*exp(c*n); stem(n,real(x));
xlabel('时间n');ylabel('振幅'); title('实数部分');
disp('PRESS RETURN for imaginary part'); pause
stem(n,imag(x));%Plot the imaginary part xlabel('Time index n');ylabel('Amplitude'); title('Imaginary part');
M2-4 (a)
L=input('desired length = ') A=input('Amplitude = ')
omega=input('angular frequency = ') phi = input('phase = ') n=0:L-1
x=A*cos(omega*n+phi) stem(n,x)
xlabel('time index' ) ylabel('amplitude')
title(['\\omega_{o} = ',num2str(omega/pi),'\\pi']) (b)
?o = 0.3?0.10.080.060.040.02amplitude0-0.02-0.04-0.06-0.08-0.1051015202530time index35404550
?o = 0.48?0.10.080.060.040.02amplitude0-0.02-0.04-0.06-0.08-0.1051015202530time index35404550
?o = 0.45?0.10.080.060.040.02amplitude0-0.02-0.04-0.06-0.08-0.1051015202530time index35404550
?o = 0.525?0.10.080.060.040.02amplitude0-0.02-0.04-0.06-0.08-0.1051015202530time index35404550
?o = 0.7?0.10.080.060.040.02amplitude0-0.02-0.04-0.06-0.08-0.1051015202530time index35404550
?o = 0.75?0.10.080.060.040.02amplitude0-0.02-0.04-0.06-0.08-0.1051015202530time index35404550
M2.6
Write a MATLAB program to plot a continuous-time sinusoidal signal and its sampled version, and verify Figure 2.28. You need to use the hold function to keep both plots. t=0:0.001:1;
fo=input('Frequency of sinusoid in Hz='); FT=input('Sampling frequency in Hz='); g1=cos(2*pi*fo*t); plot(t,g1,'-');
xlabel('time'); ylabel('Amplitude'); hold n=0:1:FT;
gs=cos(2*pi*fo*n/FT); plot(n/FT,gs,'o'); hold off
Frequency of sinusoid in Hz=5 Sampling frequency in Hz=5