# Integration parameters

SLaSi uses the Runge-Kutta-Fehlber integration method of the 4-5 order (RKF45). You need to set up the next parameters:

• timeStep — time step between snapshots (can be float value);
• snapshotCount — the total number of snaphots (integer);
• stopdMdt — is optional float parameter: when the maximal derivative $|d\mathbf m/dt|$ becomes smaller than this given value, the integration process stops (but the snaphotCount could be reached faster and program stops also);
• tolerance — the tolerance for RKF45 is the difference between integration by Runge-Kutta method of the 4-th and the 5-th orders.
• intStepCount — the default number of the integration steps per snaphot, it indirectly defines the default integration step. For example, if the timeStep equals 1.0 and intStepCount equals 50, than the initial time step for RKF45 equals 1/50 = 0.02. If the given tolerance is not obtained by the default integration step, it will be decreased. Note, that the best situation when the time step is not changed during all simulation time, because in another case it could add noise corresponding to the different time steps.