Figure 1
From: i-RheoFT: Fourier transforming sampled functions without artefacts
(Top) A single exponential decay function vs. time, representing the relaxation modulus of a single mode Maxwell fluid. (Bottom) A generic function resembling the normalised mean square displacement vs. time of an optically trapped particle suspended into a non-Newtonian fluid. Equations (2) and (3) are represented by a finite number of ‘sampled’ points and a continuous (pink) line. The points are also interpolated by means of three MATLAB built-in interpolation functions: Spline, PCHIP and Makima. The insets show the relative absolute error of each interpolation function with respect of either of Eqs. (2) and (3), as calculated using Eq. (7). The time window of the inset encompasses the final three points of the main graph, where the relative error is at its highest.
