FastFourierTransformLibrary of functions for the Fast Fourier Transform (FFT) 
Examples demonstrating the usage of the Math.FastFourierTransform functions 

Print information about real FFT for given f_max and f_resolution 

Return number of sample points for a real FFT 

Return amplitude and phase vectors for a real FFT 

Write real FFT computation to file 

Internal library that should not be used directly by a user 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This package provides functions to compute the Fast Fourier Transform (FFT).
For an example see Examples.RealFFT1 where the following signal is computed during simulation
y = 5 + 3*sin(2*pi*2) + 1.5*cos(2*pi*3)
the continuoustime signal y is sampled and the FFT is computed with a call to realFFT(f_max=4, f_resolution=0.2), resulting in: