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Fourier coeffs of a function in Matlab

  1. Apr 14, 2009 #1
    Please, people, need help!

    I have a harmonic function which is a product of cosines (something with many cos(k*phi)) and it can be represented as a finite series with only cos terms... We know it...

    Now. Every step we multiply this function by one more cos and want to find the Fourier coefs.

    So, I don't understand two things...
    1. There is no any method in Matlab to generate functions of variables as I understand... So, how can I provide this updating? I need that function of phi...
    2. Is there any command for finding nth Fourier coefficient of function, not a vector?

    Any useful tips?
  2. jcsd
  3. Apr 14, 2009 #2

    Dr Transport

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    Science Advisor
    Gold Member

    If you can write the function, set a vector of points x where the delta is very small, evaluate the function then take the FFT, the coefficients should pop right out as the real part.
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