Figure 6.

Accuracy of fixed step size simulation with Euler method and event-driven analytic simulation using fixed point operands. The accuracy of w_ij and β_j is assessed by the normalized mean absolute error taken over a large set of experiments with the exact analytical solution as reference, see text for details. (A) Simulation with Euler, dependent on step size. The dashed line shows the linear scaling: y(dt) = dt · s⁻¹. (B) Analytical solution with event-driven update (analytical II) using fixed-point representation with different counts of fractional bits. The dashed line shows the quantization noise amplitude: y(b) = 2^−b. The error bars in A and B denote the normalized maximum absolute error recorded within all simulations per setup. (C) Comparison between the errors introduced by the Euler method and the use of fixed-point numbers with limited number of fractional bits: For w_ij and β_j the location of equal mean absolute errors is plotted, depending on the step size for the Euler method, respectively the number of fractional bits of the fixed-point implementation. Dashed line: estimated relationship according to Equation (60).