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I got a data set and I want to made a Fast Fourier Transform to it, I wish I can get the coefficient of the triangle form of the Fourier series.Triangle_Form Coded in python:

px = np.fft.fft(x)

Here's what I got:

 [  4.00700000e+03 +0.00000000e+00j   8.89140903e+02 -1.13923217e+02j
  -1.69490182e+02 +1.20807444e-02j  -3.57263933e+01 -2.04340910e+02j
  -3.70833524e+01 -5.11555592e+01j  -1.20336528e+02 -2.58434734e+02j
   3.53001158e+01 -5.38317726e+01j   3.67144521e+01 -7.95005841e+01j
   9.61841452e+00 -1.23135149e+02j   4.94584769e+01 -4.71051788e+01j
...

Seems it is some coefficients of the Exponential form?Like_that

But I don't know what these data presents as a freshman. I do searched, but it is of little help. Any one could tell me how to use these returned data to construct the Fourier Transformed formula? Like, whether the data represents any value of the upper equations like x_n or a_n ?

Paul R
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Amarth Gûl
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    Python's `np.fft.fft` (and it's true for FFT in general) gives you a [**discrete** Fourier transform](https://en.wikipedia.org/wiki/Discrete_Fourier_transform), so you're not working with a continuous function *f(x)*, but with the transform of a sequence of N numbers, and the results is ... another sequence of N numbers. – Basj Jun 08 '17 at 09:26
  • @Basj I think I Got it, thank you! – Amarth Gûl Jun 08 '17 at 14:51
  • Possible duplicate of [How to calculate a Fourier series in Numpy?](https://stackoverflow.com/questions/4258106/how-to-calculate-a-fourier-series-in-numpy) – Mark Dickinson Jun 09 '17 at 14:48

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