When we plot FFT in a matlab it doesn't ask for Frequency , all we need to input the sequence and it simply shows the output using stem command. If i want to compute two different signal using FFT, one with High and the other with Low frequency what should i suppose to do ? and what will be the difference between the two of them ?
Here is simple code for the FFT calculation ,
x=[1 2 1 0] n=0:3 y=fft(x) subplot(2,2,1) stem(n,y)