\descript
    {
      Set the list of unknowns composing the schur complement.
    }
    {
      Set the list of unknowns composing the schur complement.\\
      This function must be used with \iparm{IPARM\_SCHUR} set to
      \texttt{API\_YES}.\\
      This function must be called before the graph partitioning step.\\
      After using it and performing factorization, the \texttt{schur}
      complement can be optained with \texttt{pastix\_getSchur}
      (\ref{proto:pastix_getSchur}) or \texttt{pastix\_setSchurArray}
      (\ref{proto:pastix_setSchurArray}) and the follwing solve 
      will be performed on the non-schur part of the matrix (but using
      a full lenght right-hand-side).
      
    }
