Writing S-Functions

ssSetSolverNeedsReset

Ask Simulink to reset the solver.

Syntax

• void ssSetSolverNeedsReset(SimStruct *S)
  

Arguments

S
   SimStruct representing an S-Function block or a Simulink model.

Description

This macro causes the solver for the current simulation to reinitialize variable step size and zero-crossing computations. This happens only if the solver is a variable-step, continuous solver. (The macro has no effect if the user has selected another type of solver for the current simulation.) An S-function should invoke this macro whenever changes occur in the dynamics of the S-function, e.g., a discontinuity in a state or output, that might invalidate the solver's step-size computations. Otherwise, the solver might take unnecessarily small steps, slowing down the simulation.

Note    If a change in the dynamics of the S-function necessitates reinitializing its continuous states, the S-function should reinitialize the states before invoking this macro to ensure accurate computation of the next step size.

Languages

C

Example

The following example uses this macro to ask Simulink to reset the solver.

• static void mdlOutputs(SimStruct *S, int_T tid) 
  { 
      : 
      : <snip> 
      : 
      if ( under_certain_conditions ) {
          double *x = ssGetContStates(S);
          /* reset the states */ 
          for (i=0; i<nContStates; i++) { 
              x[i] = 0.0; 
          } 
          /* Ask Simulink to reset the solver. */ 
          ssSetSolverNeedsReset(S); 
      }
  }
  

Also see the source code for the Time-Varying Continuous Transfer Function (matlabroot/simulink/src/stvctf.c) for an example of where and how to use this macro.

ssSetSFcnParamTunable

ssSetStopRequested