why matlab can't plot signals ?

clc;

clear all;

close all;

Fc= input(' Carrier frequency = ');

Fm= input(' message frequency = ');

Am=input('Message signal amplitude = ');

Ac=input('Carrier signal amplitude = ');

B=input('Modulation index = ');

t=0: 0.0001;0.1;

C_t= Ac*cos(2*pi*Fc*t);

subplot(3,1,1);

plot(t,C_t);

ylabel('amplitude');xlabel('time index');title('Carrier signal');

M_t= Am*sin(2*pi*Fm*t);

subplot(3,1,2);

plot(t,M_t);

ylabel('amplitude');xlabel('time index');title('Modulating signal');

S_t = Ac*cos((2*pi*Fc*t)+ B*cos(2*pi*Fm*t));

subplot(3,1,3);

plot(t,S_t);

ylabel('amplitude');xlabel('time index');title('Frequency Modulated signal');

[Mohamed]

Answer 1

[Dyuman Joshi]

Because there's a typo, semi-colon instead of colon in defining t.

%          v
t=0: 0.0001;0.1;

t

t = 0

t here is a scalar, which when you supplied to plot() without specifying a marker does not result in a plot.

Fix the typo and your code will work as expected.

[Mohamed]

thanks mate

[Dyuman Joshi]

You're welcome!

Answer 2

[madhan ravi]

t = 0 : 0.0001 : 0.1;
%              ^ 

[Mohamed]

thanks