Fourier transform 
noun Mathematics
A function derived from a given function and representing it by a series of sinusoidal functions.In this case, we grab 1,024 samples at a time and compute the discrete Fourier transform using the fast Fourier transform algorithm....
- The amplitudes of each of the component sine waves in the Fourier transform expresses the relative contributions of each frequency of variation to the periodicity of the original data.
- These correlation functions and their Fourier transforms, the spectral densities, can be obtained directly from MD trajectories.