Fourier coefficients

If the COS&SIN keyword is used, then the FFT function returns the actual Fourier coefficients.

Let the cosine coefficients be called   's and let the sine coefficients be called   's.    is the mean value of the input data. As shown in the example below, these coefficients can be used for smoothing and interpolation. Suppose   is the interpolation location, and 2N is the number of original data points.

If the COS&SIN keyword is used, then the FFT function returns the actual Fourier coefficients. Let the cosine coefficients be called  's and the sine coefficients be called  's.  is the mean value of the input data. As shown in the example below, these coefficients can be used for smooth interpolation. Suppose   is the interpolation location, and 2N is the number of original data points.

  Fast Fourier transform
  Discrete Fourier series