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Fft in matlab

  1. Jul 1, 2010 #1
    I have to solve a differential equation in MATLAB in (x,y) involving partial derivatives. My solution is a function of (x,y). I want to use fft differentiation( spectral method) to solve my partial derivatives.But i am stuck. I am using the following algorithm

    % fderiv = ifft((i*k).^p .* fft(f)); % pth derivative of f(matrix containing functional values).
    But when i try this for size(f)=2 ..it is not showing me the correct result.

    my x is symmetric (-L,L)

    1. does this method work with periodic f only or non periodic functions can be differentiated as well? If yes..how?
    2. How to choose k in above program?
  2. jcsd
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