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ssGetContStates - Get a block's continuous states

Syntax

real_T *ssGetContStates(SimStruct *S)

Arguments

S: SimStruct representing an S-Function block.

Returns

A pointer (real_T *) to the continuous state vector as an array of length ssGetNumContStates(S). Returns NULL if the S-function does not have any continuous states.

Description

Use in the simulation loop, mdlInitializeConditions, or mdlStart routines to get the real_T continuous state vector for the S-function. This vector has length ssGetNumContStates(S). Typically, this vector is initialized in mdlInitializeConditions and used in mdlOutputs.

Languages

C, C++

Example

The following lines from the file matlabroottoolbox/simulink/simdemos/simfeatures/src/csfunc.c show how to initialize the continuous states in mdlInitializeConditions and calculate the state derivatives in mdlDerivatives. This S-function is used in the model sfcndemo_csfunc.mdl.

static void mdlInitializeConditions(SimStruct *S)
{
    real_T *x0 = ssGetContStates(S);
    int_T lp;

    for (lp=0;lp<2;lp++) {
        *x0++=0.0;
    }
}

static void mdlDerivatives(SimStruct *S)
{
    real_T            *dx    = ssGetdX(S);
    real_T            *x     = ssGetContStates(S);
    InputRealPtrsType uPtrs  = ssGetInputPortRealSignalPtrs(S,0);
    /* xdot = Ax + Bu */
    dx[0]=A[0][0]*x[0]+A[1][1]*x[1]+B[0][0]*U(0)+B[0][1]*U(1);
    dx[1]=A[1][0]*x[0]+A[1][1]*x[1]+B[1][0]*U(0)+B[1][1]*U(1);
}