    // @(#)root/quadp:$Name:  $:$Id: TQpLinSolverSparse.cxx,v 1.4 2004/06/09 12:23:16 brun Exp $
    // Author: Eddy Offermann   May 2004

    /*************************************************************************
     * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
     * All rights reserved.                                                  *
     *                                                                       *
     * For the licensing terms see $ROOTSYS/LICENSE.                         *
     * For the list of contributors see $ROOTSYS/README/CREDITS.             *
     *************************************************************************/

    /*************************************************************************
     * Parts of this file are copied from the OOQP distribution and          *
     * are subject to the following license:                                 *
     *                                                                       *
     * COPYRIGHT 2001 UNIVERSITY OF CHICAGO                                  *
     *                                                                       *
     * The copyright holder hereby grants you royalty-free rights to use,    *
     * reproduce, prepare derivative works, and to redistribute this software*
     * to others, provided that any changes are clearly documented. This     *
     * software was authored by:                                             *
     *                                                                       *
     *   E. MICHAEL GERTZ      gertz@mcs.anl.gov                             *
     *   Mathematics and Computer Science Division                           *
     *   Argonne National Laboratory                                         *
     *   9700 S. Cass Avenue                                                 *
     *   Argonne, IL 60439-4844                                              *
     *                                                                       *
     *   STEPHEN J. WRIGHT     swright@cs.wisc.edu                           *
     *   Computer Sciences Department                                        *
     *   University of Wisconsin                                             *
     *   1210 West Dayton Street                                             *
     *   Madison, WI 53706   FAX: (608)262-9777                              *
     *                                                                       *
     * Any questions or comments may be directed to one of the authors.      *
     *                                                                       *
     * ARGONNE NATIONAL LABORATORY (ANL), WITH FACILITIES IN THE STATES OF   *
     * ILLINOIS AND IDAHO, IS OWNED BY THE UNITED STATES GOVERNMENT, AND     *
     * OPERATED BY THE UNIVERSITY OF CHICAGO UNDER PROVISION OF A CONTRACT   *
     * WITH THE DEPARTMENT OF ENERGY.                                        *
     *************************************************************************/

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TQpLinSolverSparse                                                   //
    //                                                                      //
    // Implements the aspects of the solvers for dense general QP           //
    // formulation that are specific to the dense case.                     //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #include "Riostream.h"
    #include "TQpLinSolverSparse.h"

    ClassImp(TQpLinSolverSparse)

    //______________________________________________________________________________
     TQpLinSolverSparse::TQpLinSolverSparse(TQpProbSparse *factory,TQpDataSparse *data) :
                        TQpLinSolverBase(factory,data)
    {
      const Int_t n = factory->fNx+factory->fMy+factory->fMz;
      fKkt.ResizeTo(n,n);

      if (fMy > 0) data->PutAIntoAt(fKkt,fNx,    0);
      if (fMz > 0) data->PutCIntoAt(fKkt,fNx+fMy,0);

      // trick to make sure that A and C are inserted symmetrically
      if (fMy > 0 || fMz > 0) {
        TMatrixDSparse tmp(TMatrixDSparse::kTransposed,fKkt);
        fKkt += tmp;
      }

      data->PutQIntoAt(fKkt,0,0);
    }

    //______________________________________________________________________________
     void TQpLinSolverSparse::Factor(TQpDataBase *prob,TQpVar *vars)
    {
      TQpLinSolverBase::Factor(prob,vars);
      fSolveSparse.SetMatrix(fKkt);
    }

    //______________________________________________________________________________
     TQpLinSolverSparse::TQpLinSolverSparse(const TQpLinSolverSparse &another) :
                        TQpLinSolverBase(another)
    {
      *this = another;
    }

    //______________________________________________________________________________
     void TQpLinSolverSparse::PutXDiagonal(TVectorD &xdiag)
    {
      TMatrixDSparseDiag diag(fKkt);
      for (Int_t i = 0; i < xdiag.GetNrows(); i++)
         diag[i] = xdiag[i];
    }

    //______________________________________________________________________________
     void TQpLinSolverSparse::PutZDiagonal(TVectorD &zdiag)
    {
      TMatrixDSparseDiag diag(fKkt);
      for (Int_t i = 0; i < zdiag.GetNrows(); i++)
        diag[i+fNx+fMy] = zdiag[i];
    }

    //______________________________________________________________________________
     void TQpLinSolverSparse::SolveCompressed(TVectorD &compressedRhs)
    {
      fSolveSparse.Solve(compressedRhs);
    }

    //______________________________________________________________________________
    TQpLinSolverSparse &TQpLinSolverSparse::operator=(const TQpLinSolverSparse &source)
    {
      if (this != &source) {
        TQpLinSolverBase::operator=(source);
        fKkt.ResizeTo(source.fKkt); fKkt = source.fKkt;
        fSolveSparse = source.fSolveSparse;
      }
      return *this;
    }