Does fft() always require 2^n sample points?

Hi, Does FFT always require 2^n? why is that? Thank you.

Answer 1

[Azzi Abdelmalek]

No. any number of samples. Just try it. The algorithm needs 2*n samples to have even samples and odd samples. If you have odd number, you can add a 0 to your samples then use the fft algorithm, at the end you have just to take in account your original samples.

[Nina]

Thank you Azzi, but could you please be kind and clarify what you meant by "at the end you have just to take in account your original samples."? where does that come into play? sorry I am really new to this whole thing so I don't have much background...

[Surendra Maharjan]

Dear Nina,

A = [1 2 3 4 5];

B = [1 2 3 4 5 0 0 0];

For example, A is your row matrix, then you can add three zeros to make A into power multiples of 2. So, B has 8 elements. Then, you can perform C = fft(B,[],2),,[] indicates matrix and 2 indicates the fft direction in row.