max@0: // Copyright (C) 2009-2010 NICTA (www.nicta.com.au)
max@0: // Copyright (C) 2009-2010 Conrad Sanderson
max@0: // 
max@0: // This file is part of the Armadillo C++ library.
max@0: // It is provided without any warranty of fitness
max@0: // for any purpose. You can redistribute this file
max@0: // and/or modify it under the terms of the GNU
max@0: // Lesser General Public License (LGPL) as published
max@0: // by the Free Software Foundation, either version 3
max@0: // of the License or (at your option) any later version.
max@0: // (see http://www.opensource.org/licenses for more info)
max@0: 
max@0: 
max@0: //! \addtogroup fn_sort_index
max@0: //! @{
max@0: 
max@0: 
max@0: 
max@0: 
max@0: template<typename T1, typename T2>
max@0: struct arma_sort_index_packet_ascend
max@0:   {
max@0:   T1 val;
max@0:   T2 index;
max@0:   };
max@0: 
max@0: 
max@0: 
max@0: template<typename T1, typename T2>
max@0: struct arma_sort_index_packet_descend
max@0:   {
max@0:   T1 val;
max@0:   T2 index;
max@0:   };
max@0: 
max@0: 
max@0: 
max@0: template<typename T1, typename T2>
max@0: inline
max@0: bool
max@0: operator< (const arma_sort_index_packet_ascend<T1,T2>& A, const arma_sort_index_packet_ascend<T1,T2>& B)
max@0:   {
max@0:   return A.val < B.val;
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T1, typename T2>
max@0: inline
max@0: bool
max@0: operator< (const arma_sort_index_packet_descend<T1,T2>& A, const arma_sort_index_packet_descend<T1,T2>& B)
max@0:   {
max@0:   return A.val > B.val;
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename umat_elem_type, typename packet_type, typename eT>
max@0: void
max@0: inline
max@0: sort_index_helper(umat_elem_type* out_mem, std::vector<packet_type>& packet_vec, const eT* in_mem)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword n_elem = packet_vec.size();
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     packet_vec[i].val   = in_mem[i];
max@0:     packet_vec[i].index = i;
max@0:     }
max@0:   
max@0:   std::sort( packet_vec.begin(), packet_vec.end() );
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     out_mem[i] = packet_vec[i].index;
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T1>
max@0: inline
max@0: umat
max@0: sort_index(const Base<typename T1::elem_type,T1>& X, const uword sort_type = 0)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   typedef typename T1::elem_type eT;
max@0:   
max@0:   arma_type_check(( is_complex<eT>::value == true ));
max@0:   
max@0:   const unwrap<T1> tmp(X.get_ref());
max@0:   const Mat<eT>& A = tmp.M;
max@0:   
max@0:   if(A.is_empty() == true)
max@0:     {
max@0:     return umat();
max@0:     }
max@0:   
max@0:   arma_debug_check( (A.is_vec() == false), "sort_index(): currently only handles vectors");
max@0:   
max@0:   typedef typename umat::elem_type out_elem_type;
max@0:   
max@0:   umat out(A.n_rows, A.n_cols);
max@0:   
max@0:   if(sort_type == 0)
max@0:     {
max@0:     std::vector< arma_sort_index_packet_ascend<eT,out_elem_type> > packet_vec(A.n_elem);
max@0:     
max@0:     sort_index_helper(out.memptr(), packet_vec, A.mem);
max@0:     }
max@0:   else
max@0:     {
max@0:     std::vector< arma_sort_index_packet_descend<eT,out_elem_type> > packet_vec(A.n_elem);
max@0:     
max@0:     sort_index_helper(out.memptr(), packet_vec, A.mem);
max@0:     }
max@0:   
max@0:   return out;
max@0:   }
max@0: 
max@0: 
max@0: //! @}