Generate frequency spectrum of original and regenerated signal

Hi I am using code from this video https://www.youtube.com/watch?v=Ww_8hPQcCHs&feature=youtu.be . I want to generate frequency spectrum of signal xa and xr. Can you guide me how to generate it.

A=1;F=2;theta=0;

dt=0.001;

t=0:dt:1;

xa=A*sin(2*pi*F*t + theta);

subplot(3,1,1);

plot(t,xa);

xlabel('time (sec)');

ylabel('xa');

title('Analogue (continous) Input Signal', 'LineWidth',5);

Fs=6*F; Ts=1/Fs;

n=Fs;

n1=0:Ts:n*Ts;

xs=A*sin(2*pi*F*n1+theta);

subplot(3,1,2);

stem(n1,xs);

xlabel('samples (n)');

ylabel('xs');

title('Discrete Time Signal', 'LineWidth',5);

t1=linspace(0,max(n1),(max(n1)/dt));

xr=interp1(n1,xs,t1,"linear");

subplot(3,1,3);

plot(t1,xr);

xlabel('time (sec)');

ylabel('xr');

title('Reconstructed Signal', 'LineWidth',5);

Answer 1

[Sam Chak]

Hi @Laveeza

You can copy and paste it on the Workspace and hit [Enter] to run it.

If you want to edit the code in the future, paste into a blank script, save a filename, maybe 'freq_gen.m' in a folder, and then "Run" it.

More info on how to add folders to search path:

https://www.mathworks.com/help/matlab/ref/addpath.html

A     = 1;
F     = 2;
theta = 0;
dt    = 0.001;
t     = 0:dt:1;
xa    = A*sin(2*pi*F*t + theta);

subplot(3,1,1);
plot(t, xa);
xlabel('time (sec)');
ylabel('xa');
title('Analogue (continous) Input Signal', 'LineWidth',5);

Fs = 6*F; 
Ts = 1/Fs;
n  = Fs;
n1 = 0:Ts:n*Ts;
xs = A*sin(2*pi*F*n1 + theta);

subplot(3,1,2);
stem(n1, xs);
xlabel('samples (n)');
ylabel('xs');
title('Discrete Time Signal', 'LineWidth',5);

t1 = linspace(0, max(n1), (max(n1)/dt));
xr = interp1(n1, xs, t1, "linear");

subplot(3,1,3);
plot(t1, xr);
xlabel('time (sec)');
ylabel('xr');
title('Reconstructed Signal', 'LineWidth',5);