============================================================================

>>> pSARC SARC_ALLOC( pMIMO pmimo , string *instname )

    The "SARC_ALLOC" function allocates a SARC data structure DIMENSIONED to
    handle the MIMO circuit passed in parameter

    The relevant MIMO informations are duplicated in the SARC data structure

    THEREFORE, the user should in fact access ALL its relevant model
               informations, never through a "pMIMO" pointer,
               but through the "pSARC" pointer returned by the call

    ============================================================================

>>> int SARC_STEPY( pSARC psarc , MIMO_FTYPE *array_Y , MIMO_FTYPE *array_U )

    The "SARC_STEPY" function computes the "Y" output vector resulting from the
    SARC STEP evaluation on the "U" input vector

    In order to take into account the latest simulation setup,

      the function FIRST checks if any modeling parameters have changed:

                                       psarc->h
                                or any psarc->RLC[ k ] component values

                   THEN, and only when NECESSARY, the matrices A, B, C , D , ...
                         are recalculated

                FINALLY, and only when "array_U" is NOT a NULL pointer,
                         the "Y" STEP evaluation is performed

    The return value will be 0       if no matrice recalculation performed
                             1  001  if "h" was found different
                             2  010  if some "R" components have changed
                             4  100  if some "L" or "C" components have changed
                                     ( thus, forcing a "STATE" vector "BURST" )
                             n  xxx  the bitwise "OR" value of the 001, 010, 100

    Therefore a positive return value corresponds to the kind of percussion
    expected

    NOTE:  This package implements a SARC "S0B" therefore the FIRST CALL of this
           function returns a vector of ZEROS

    ============================================================================

>>> void SARC_ERRY( pSARC psarc , MIMO_FTYPE *array_YE , MIMO_FTYPE *array_YM )

    The "SARC_ERRY" function computes the "Y" vector ERRORs resulting from the
    input vector "U" INTERPOLATION STEP

      with  YE[ k ] is the Y[ k ] output            INTERPOLATION STEP ERROR
            YM[ k ] is the Y[ k ] output MAX( ABS ( INTERPOLATION STEP ERROR ) )

    Therefore, at the end of the simulation, YM[ k ] contains a MAJORANT of the
    overall Y[ k ] output RUNTIME ERROR

     WARNING: when enabled, this call must be performed AFTER the "SARC_STEPY )"
              function
        NOTE: This package implements a SARC "S0B" therefore the FIRST CALL of
              this function returns vectors of ZEROS

    ============================================================================

>>> void SARC_POLES( pSARC psarc , MIMO_FTYPE *POLES )

    This function CALCULATES the "POLES" (that are the psarc->A "EIGEN" values)
    and SAVES them as a matrix POLES[ n , 2 ]

        with POLES[ k , 0 ] = REAL part  and  POLES[ k , 1 ] = IMAGINARY part

    DIMENSION:  POLES[ nstate ][ 2 ]

    ============================================================================

>>> void SARC_PRINTPOLES( pSARC psarc )

    This function CALCULATES the "POLES" (that are the psarc->A "EIGEN" values)
    and PRINTS them as a matrix POLES[ n , 2 ]

        with POLES[ k , 0 ] = REAL part  and  POLES[ k , 1 ] = IMAGINARY part

    ============================================================================

>>> The "sarc_printmatrix" function is not to be called directly

    The "SARC_api.h" MACRO   SARC_PRINTMATRIX( psarc , mat ) does "printf" the
    content of the SARC EIGEN matrix "pSARC->mat"

         example:  SARC_PRINTMATRIX( psarc , A )  does printf
         ========
                      >>> SARC  MIMO_rlc -> i1 -> POLES
                         -5.000000000000E+02    3.161882350752E+04
                         -5.000000000000E+02   -3.161882350752E+04

    ============================================================================