A computer system that formerly handled a service is quickly reproduced with another computer system to resume the service immediately. Various routines executable on the handheld electronic device can cause visual elements to be output in various predetermined arrangements with respect to the arrangement of the tactile structures in order to facilitate input. Thus, the compiler saves register-pressure data during the first compilation and uses it during the second compilation to make informed inlining decisions. The method may further model characteristic impedances of the lines via rational function models and estimate parameters of the rational function models via further cost functions which depend on outcomes of the physical models.