Max step size

Description

Specify the largest time step that the solver can take.

Category: Solver

Settings

Default: auto

  • For the discrete solver, the default value (auto) is the model's shortest sample time.

  • For continuous solvers, the default value (auto) is determined from the start and stop times. If the stop time equals the start time or is inf, Simulink® chooses 0.2 seconds as the maximum step size. Otherwise, it sets the maximum step size to

    hmax=tstoptstart50

  • For Sine and Signal Generator source blocks, Simulink calculates the max step size using this heuristic:

    where Freqmax is the maximum frequency (Hz) of these blocks in the model.

Tips

  • Generally, the default maximum step size is sufficient. If you are concerned about the solver missing significant behavior, change the parameter to prevent the solver from taking too large a step.

  • Max step size determines the step size of the variable-step solver.

  • If the time span of the simulation is very long, the default step size might be too large for the solver to find the solution.

  • If your model contains periodic or nearly periodic behavior and you know the period, set the maximum step size to some fraction (such as 1/4) of that period.

  • In general, for more output points, change the refine factor, not the maximum step size.

Dependencies

This parameter is enabled only if the solver Type is set to Variable-step.

Command-Line Information

Parameter: MaxStep
Type: character vector
Value: any valid value
Default: 'auto'

Recommended Settings

ApplicationSetting
DebuggingNo impact
TraceabilityNo impact
EfficiencyNo impact
Safety precautionNo impact

Related Topics