CPPLapack Code

//=============================================================================
/*! return transposed dgematrix */
inline _dsymatrix t(const dsymatrix& mat)
{VERBOSE_REPORT;
#ifdef  CPPL_DEBUG
  WARNING_REPORT;
  std::cerr << "This function call has no effect since the matrix is symmetric." << std::endl;
#endif//CPPL_DEBUG
  
  dsymatrix newmat(mat);
  return _(newmat);
}

//=============================================================================
/*! return its inverse matrix */
inline _dsymatrix i(const dsymatrix& mat)
{VERBOSE_REPORT;
  dsymatrix mat_cp(mat);
  dsymatrix mat_inv(mat.n);
  mat_inv.identity();
  
  char UPLO('l');
  long NRHS(mat.n), LDA(mat.n), *IPIV(new long[mat.n]), LDB(mat.n), LWORK(-1), INFO(1);
  double *WORK( new double[1] );
  dsysv_(UPLO, mat.n, NRHS, mat_cp.array, LDA, IPIV, mat_inv.array, LDB, WORK, LWORK, INFO);
  LWORK = long(WORK[0]);
  delete [] WORK;  WORK = new double[LWORK];
  dsysv_(UPLO, mat.n, NRHS, mat_cp.array, LDA, IPIV, mat_inv.array, LDB, WORK, LWORK, INFO);
  delete [] WORK; delete [] IPIV;
  if(INFO!=0){
    WARNING_REPORT;
    std::cerr << "Serious trouble happend. INFO = " << INFO << "." << std::endl;
  }
  
  return _(mat_inv);
}


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//=============================================================================
/*! search the index of element having the largest absolute value
  in 0-based numbering system */
inline void idamax(long& i, long& j, const dsymatrix& mat)
{VERBOSE_REPORT;
  i=j=0;
  double val(0.);
  for(long J=0; J<mat.n; J++){
    long I( J +idamax_(mat.m-J, mat.darray[J]+J, 1) -1 );
    if( val<fabs(mat.darray[J][I]) ){
      val =fabs(mat.darray[J][I]);
      i=I;
      j=J;
    }
  }
}

//=============================================================================
/*! return its largest absolute value */
inline double damax(const dsymatrix& mat)
{VERBOSE_REPORT;
  long i,j;
  idamax(i, j, mat);
  return mat(i,j);
}