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Initial step size

Size of first time step for variable-step solver

Model Configuration Pane: Solver


Specify the size of the first time step, in seconds, for the variable-step solver.


To enable this parameter, set the solver Type to Variable-step.


auto (default) | scalar number

By default, the Initial step size value is auto, which indicates that the solver determines the initial step size by examining the derivatives of the states at the start of the simulation.

Be careful when specifying an initial step size other than auto. If the first step size is too large, the solver might step over important behavior.

When you specify an initial step size, the solver takes a smaller step than specified when error criteria are not met.

Recommended Settings

The table summarizes recommended values for this parameter based on considerations related to code generation.

DebuggingNo impact
TraceabilityNo impact
EfficiencyNo impact
Safety precautionNo impact

Programmatic Use

Parameter: InitialStep
Type: string | character vector
Value: scalar number
Default: 'auto'

Version History

Introduced before R2006a