Get the derivatives of a block's continuous states
real_T *ssGetdX(SimStruct *S)
A pointer (real_T *) to an array containing the derivatives of the continuous states of S, which can be a block or the model. Returns NULL if there are no continuous states.
Use this macro in mdlDerivatives to get the derivatives of a model or block's continuous states. Use ssGetNumContStates(S) to get the length of the array.