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(adsbygoogle = window.adsbygoogle || []).push({});

% 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?

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# Fft in matlab

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