Fig. 4.
Analysis of parameter sensitivity. The distributions of model parameters and cost function (Jc) are shown for the selection of best optimization sets. Each subplot shows a mean with standard deviation of the parameter values in blue (flexor), red (extensor), and green (mixed) for four types of minimization algorithms. The vertical axis range reflects the full feasible range of parameters as determined by the examination of intermediate solutions (see step 6 in section Optimization and parameter perturbation of methods), with the exception for the Jc values. cobyla, Nonlinear optimization algorithm COBYLA; lbfgsb, L-BFGS-B algorithm; powell, Powell’s algorithm; tnc, Truncated Newton’s.