convert cartesian plot into frequency domain

How can I convert Cartesian plot into frequency domain?? Please, help!

Answer 1

[AR]

Hi I@Irena Chernova,

We can use the Fast Fourier Transform, “fft” function to convert a cartesian plot into the frequency domain. It takes as input a vector or matrix containing the time-domain data and provides an output of the same size in the frequency domain.

Here is an example code to convert time domain data to frequency domain.

t = 0:0.001:1;                 % Time vector 
x = sin(2*pi*50*t);            % Example signal 
N = length(x); 
Fs = 1/(t(2)-t(1));            % Sampling frequency 
X = fft(x); 
f = (0:N-1)*(Fs/N); 
magnitude = abs(X)/N; 
half_N = floor(N/2)+1; 
figure; 
plot(f(1:half_N), magnitude(1:half_N)); 
xlabel('Frequency (Hz)'); 
ylabel('Magnitude'); 
title('Frequency Domain Representation'); 

To convert a Cartesian plot to the frequency domain, apply the “fft” to the y-data (the signal values), not to the plot itself. The x-axis of the original plot is typically time or space, and the y-axis is the signal amplitude.

For more information on “fft”, refer to the below documentation link:

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