Determining mesh parameters.

<p><b>(A)</b> Experimental setup: trajectories of mass points (large big dots) are traced during a spiral wave rotation during in a medium size of along each side. The color spectrum indicates (local) dilatation (scaled) in the medium (). Maximal local deformations . <b>(B)</b><i>vs</i> with , and using to compute reference trajectories. The dotted horizontal line indicates the parameter chosen for further computations (). <b>(C)</b><i>vs.</i> with , , and to compute reference trajectories. <b>(D)</b><i>vs.</i> with , and to compute reference trajectories.