I Wrote a Code For Fast Fourier Transformation With a Sin Function

I created a code plots a sin(2*pi*f*t) function in t=-4:0.001:4 with period (T) 5ms.

Then by using Fast Fourier Transformation (FFT), I converted the function from time domain to frequency domain and plotted it.

Here is my code that I have written:

Did I do correctly or Do I have a mistake?

fs = 1000;                             %sampling freq.
t = -4 : 1/fs : 4;                       %period which is between -4 to 4
f = 200;
x = sin(2*pi*f*t);                        %function is time domain
n = length(t);                           %length of interval
Fou_x = (fft(x));                       %fourier transform of function
Foushift_x = fftshift(Fou_x);            %shift to zero
finterval = fs/n;                        %increasing value of freq. interval
f = -fs/2 : finterval : fs/2-finterval; %freq. interval

figure;
plot(f, abs(Foushift_x)/n);               %plot freq. function interval
xlabel('Frequency (in Hertz');
title('Magnitude');

Answer 1

[Benjamin Thompson]

Looks correct. The amplitude of your input signal is divided between the left and right half of the output. Type the command "doc fft" for a more detailed example.

[cikalekli]

Thank you so much. Have a nice day!