has characteristic is hybrid of has parameter Gibson-Bruck next reaction algorithm deterministic system behaviour stochastic system behaviour particle number lower limit particle number upper limit Pahle hybrid method 1 1 http://identifiers.org/biosimulators/copasi http://identifiers.org/doi/10.1093/bioinformatics/btl485 true AZ The hybrid method combines the stochastic 'Gibson-Bruck's next reaction method' [http://identifiers.org/biomodels.kisao/KISAO_0000027] with different algorithms for the numerical integration of ODEs [http://identifiers.org/biomodels.kisao/KISAO_0000245 some http://identifiers.org/biomodels.kisao/KISAO_0000374]. The biochemical network is dynamically partitioned into a deterministic and a stochastic subnet depending on the current particle numbers in the system. The user can define limits for when a particle number should be considered low or high. The stochastic subnet contains reactions involving low numbered species as substrate or product. All the other reactions form the deterministic subnet. The two subnets are then simulated in parallel using the stochastic and deterministic solver, respectively. The reaction probabilities in the stochastic subnet are approximated as constant between two stochastic reaction events. hybrid method ordinary differential equation problem