// @(#)root/minuit2:$Id: LaOuterProduct.cxx 20880 2007-11-19 11:23:41Z rdm $
// Authors: M. Winkler, F. James, L. Moneta, A. Zsenei   2003-2005  

/**********************************************************************
 *                                                                    *
 * Copyright (c) 2005 LCG ROOT Math team,  CERN/PH-SFT                *
 *                                                                    *
 **********************************************************************/

#include "Minuit2/LaOuterProduct.h"
#include "Minuit2/LAVector.h"
#include "Minuit2/LASymMatrix.h"

namespace ROOT {

   namespace Minuit2 {


int mndspr(const char*, unsigned int, double, const double*, int, double*);

LASymMatrix::LASymMatrix(const ABObj<sym, VectorOuterProduct<ABObj<vec, LAVector, double>, double>, double>& out) : fSize(0), fNRow(0), fData(0) {
   // constructor from expression based on outer product of symmetric matrices
   //   std::cout<<"LASymMatrix::LASymMatrix(const ABObj<sym, VectorOuterProduct<ABObj<vec, LAVector, double>, double>, double>& out)"<<std::endl;
   fNRow = out.Obj().Obj().Obj().size();
   fSize = fNRow*(fNRow+1)/2;
   fData = (double*)StackAllocatorHolder::Get().Allocate(sizeof(double)*fSize);
   memset(fData, 0, fSize*sizeof(double));
   Outer_prod(*this, out.Obj().Obj().Obj(), out.f()*out.Obj().Obj().f()*out.Obj().Obj().f());
}

LASymMatrix& LASymMatrix::operator=(const ABObj<sym, VectorOuterProduct<ABObj<vec, LAVector, double>, double>, double>& out) {
   // assignment operator from expression based on outer product of symmetric matrices   
   //   std::cout<<"LASymMatrix& LASymMatrix::operator=(const ABObj<sym, VectorOuterProduct<ABObj<vec, LAVector, double>, double>, double>& out)"<<std::endl;
   if(fSize == 0 && fData == 0) {
      fNRow = out.Obj().Obj().Obj().size();
      fSize = fNRow*(fNRow+1)/2;
      fData = (double*)StackAllocatorHolder::Get().Allocate(sizeof(double)*fSize);
      memset(fData, 0, fSize*sizeof(double));
      Outer_prod(*this, out.Obj().Obj().Obj(), out.f()*out.Obj().Obj().f()*out.Obj().Obj().f());
   } else {
      LASymMatrix tmp(out.Obj().Obj().Obj().size());
      Outer_prod(tmp, out.Obj().Obj().Obj());
      tmp *= double(out.f()*out.Obj().Obj().f()*out.Obj().Obj().f());
      assert(fSize == tmp.size());
      memcpy(fData, tmp.Data(), fSize*sizeof(double));
   }
   return *this;
}

void Outer_prod(LASymMatrix& A, const LAVector& v, double f) {
   // function performing outer product using mndspr (DSPR) routine from BLAS
   mndspr("U", v.size(), f, v.Data(), 1, A.Data());
}

   }  // namespace Minuit2

}  // namespace ROOT
