Fig 6. Model sensitivity calculated through exploring phase space.

Sensitivity analysis examining the goodness of fit of the generalized SPP model to displacement distributions in mouse fibroblasts (1 − R²) as a function of model parameters. (A) Contour plot of log(1 − R²) illustrates the experimental data tightly constrains a linear combination of the mean velocity μ_v and mean noise μ_D, where the minima is highlighted by a white circle. (B, C) The goodness of fit as a function of each model parameter while all others are held fixed. (B) $\overrightarrow{r_0}$ is the optimal coordinate in parameter space and $\overrightarrow{r}-\overrightarrow{r_0}$ is the distance of each parameter from its optimal value. (C) A value of τ smaller than ≈ 10 is inconsistent with experimental data, but data does not discriminate between larger values of τ.