Question

Using Matlab. I need the matlab code for:

a. Plot a 1 Hz sine wave

b. Plot the unit rectangle function.

c. Plot the unit triangle function

Show each over a plotting interval -5 sec to 5 sec.

Answer 1

1)

To Plot 1Hz sine wave:

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Fs = 10000; % samples per second

dt = 1/Fs; % seconds per sample

StopTime = 5; % seconds

t = (-5:dt:StopTime-dt)'; % seconds

%%Sine wave:

Fc = 1; % hertz

x = cos(2*pi*Fc*t);

% Plot the signal versus time:

figure;

plot(t,x);

xlabel('time (in seconds)');

title('Signal versus Time');

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2)

Plotting unit Rectangle function:

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rectangle=@(x,a) ones(1,numel(x)).*(abs(x)<a/2) % a is the width of the pulse

x=-5:0.001:5

y=rectangle(x,2)

plot(x,y)

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3)

Plotting unit Triangle function:

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t = -5:0.005:5;

g_t = 0;

g_a = sin(2*pi*t)+(0.5*cos(6*pi*t))+(0.25*cos(18*pi*t)); %given

B = 10;

for n = 1:20

h = 2*B*t-n;

g_t = g_t + (n/(2*B)).*g_a.*(1-abs(2*B*t-n));

end

figure(1);

hold on;

box on;

plot(t,g_t,'r');

plot(t,g_a,'b');

ylabel('amplitude g(t)');

xlabel('time t');

title('sync waveform reconstruction');

axis([0 1 -2 2]);

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