Running times for flux variability analysis. Running time of flux variability analysis in various software packages using the GNU Linear Programming Kit (GLPK). Time was measured in R with the function Rprof() and in MATLAB with the Profiler function. In both cases, the running time of a function is reported as "total time". For OptFlux, the Unix command top in delta mode was used. SBRT itself reports the elapsed time for flux variability analysis. For FASIMU, the "real time" reported by the Unix command time was used. For COBRApy, the Python module time was used. All simulations were run ten times on the same desktop PC (Intel Xeon, 2.8 GHz, running Mac OS 10.7). The reported running times are arithmetic means of these values.