Chris@49: // Copyright (C) 2008-2012 NICTA (www.nicta.com.au)
Chris@49: // Copyright (C) 2008-2012 Conrad Sanderson
Chris@49: // 
Chris@49: // This Source Code Form is subject to the terms of the Mozilla Public
Chris@49: // License, v. 2.0. If a copy of the MPL was not distributed with this
Chris@49: // file, You can obtain one at http://mozilla.org/MPL/2.0/.
Chris@49: 
Chris@49: 
Chris@49: //! \addtogroup op_sort
Chris@49: //! @{
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: class arma_ascend_sort_helper
Chris@49:   {
Chris@49:   public:
Chris@49:   
Chris@49:   arma_inline
Chris@49:   bool
Chris@49:   operator() (eT a, eT b) const
Chris@49:     {
Chris@49:     return (a < b);
Chris@49:     }
Chris@49:   };
Chris@49:   
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: class arma_descend_sort_helper
Chris@49:   {
Chris@49:   public:
Chris@49:   
Chris@49:   arma_inline
Chris@49:   bool
Chris@49:   operator() (eT a, eT b) const
Chris@49:     {
Chris@49:     return (a > b);
Chris@49:     }
Chris@49:   };
Chris@49:   
Chris@49: 
Chris@49: 
Chris@49: template<typename T>
Chris@49: class arma_ascend_sort_helper< std::complex<T> >
Chris@49:   {
Chris@49:   public:
Chris@49:   
Chris@49:   typedef typename std::complex<T> eT;
Chris@49:   
Chris@49:   inline
Chris@49:   bool
Chris@49:   operator() (const eT& a, const eT& b) const
Chris@49:     {
Chris@49:     return (std::abs(a) < std::abs(b));
Chris@49:     }
Chris@49:   };
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T>
Chris@49: class arma_descend_sort_helper< std::complex<T> >
Chris@49:   {
Chris@49:   public:
Chris@49:   
Chris@49:   typedef typename std::complex<T> eT;
Chris@49:   
Chris@49:   inline
Chris@49:   bool
Chris@49:   operator() (const eT& a, const eT& b) const
Chris@49:     {
Chris@49:     return (std::abs(a) > std::abs(b));
Chris@49:     }
Chris@49:   };
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: inline 
Chris@49: void
Chris@49: op_sort::direct_sort(eT* X, const uword n_elem, const uword sort_type)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   if(sort_type == 0)
Chris@49:     {
Chris@49:     arma_ascend_sort_helper<eT> comparator;
Chris@49:     
Chris@49:     std::sort(&X[0], &X[n_elem], comparator);
Chris@49:     }
Chris@49:   else
Chris@49:     {
Chris@49:     arma_descend_sort_helper<eT> comparator;
Chris@49:     
Chris@49:     std::sort(&X[0], &X[n_elem], comparator);
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: inline 
Chris@49: void
Chris@49: op_sort::direct_sort_ascending(eT* X, const uword n_elem)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   arma_ascend_sort_helper<eT> comparator;
Chris@49:     
Chris@49:   std::sort(&X[0], &X[n_elem], comparator);
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: inline 
Chris@49: void
Chris@49: op_sort::copy_row(eT* X, const Mat<eT>& A, const uword row)
Chris@49:   {
Chris@49:   const uword N = A.n_cols;
Chris@49:   
Chris@49:   uword i,j;
Chris@49:   
Chris@49:   for(i=0, j=1; j<N; i+=2, j+=2)
Chris@49:     {
Chris@49:     X[i] = A.at(row,i);
Chris@49:     X[j] = A.at(row,j);
Chris@49:     }
Chris@49:   
Chris@49:   if(i < N)
Chris@49:     {
Chris@49:     X[i] = A.at(row,i);
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: inline 
Chris@49: void
Chris@49: op_sort::copy_row(Mat<eT>& A, const eT* X, const uword row)
Chris@49:   {
Chris@49:   const uword N = A.n_cols;
Chris@49:   
Chris@49:   uword i,j;
Chris@49:   
Chris@49:   for(i=0, j=1; j<N; i+=2, j+=2)
Chris@49:     {
Chris@49:     A.at(row,i) = X[i]; 
Chris@49:     A.at(row,j) = X[j];
Chris@49:     }
Chris@49:   
Chris@49:   if(i < N)
Chris@49:     {
Chris@49:     A.at(row,i) = X[i];
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1>
Chris@49: inline
Chris@49: void
Chris@49: op_sort::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_sort>& in)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   typedef typename T1::elem_type eT;
Chris@49:   
Chris@49:   const unwrap_check<T1>   tmp(in.m, out);
Chris@49:   const Mat<eT>&       X = tmp.M;
Chris@49:   
Chris@49:   const uword sort_type = in.aux_uword_a;
Chris@49:   const uword dim       = in.aux_uword_b;
Chris@49:   
Chris@49:   arma_debug_check( (sort_type > 1),          "sort(): incorrect usage. sort_type must be 0 or 1");
Chris@49:   arma_debug_check( (dim > 1),                "sort(): incorrect usage. dim must be 0 or 1"      );
Chris@49:   arma_debug_check( (X.is_finite() == false), "sort(): given object has non-finite elements"     );
Chris@49:   
Chris@49:   if( (X.n_rows * X.n_cols) <= 1 )
Chris@49:     {
Chris@49:     out = X;
Chris@49:     return;
Chris@49:     }
Chris@49:   
Chris@49:   
Chris@49:   if(dim == 0)  // sort the contents of each column
Chris@49:     {
Chris@49:     arma_extra_debug_print("op_sort::apply(), dim = 0");
Chris@49:     
Chris@49:     out = X;
Chris@49:     
Chris@49:     const uword n_rows = out.n_rows;
Chris@49:     const uword n_cols = out.n_cols;
Chris@49:       
Chris@49:     for(uword col=0; col < n_cols; ++col)
Chris@49:       {
Chris@49:       op_sort::direct_sort( out.colptr(col), n_rows, sort_type );
Chris@49:       }
Chris@49:     }
Chris@49:   else
Chris@49:   if(dim == 1)  // sort the contents of each row
Chris@49:     {
Chris@49:     if(X.n_rows == 1)  // a row vector
Chris@49:       {
Chris@49:       arma_extra_debug_print("op_sort::apply(), dim = 1, vector specific");
Chris@49:       
Chris@49:       out = X;
Chris@49:       op_sort::direct_sort(out.memptr(), out.n_elem, sort_type);
Chris@49:       }
Chris@49:     else  // not a row vector
Chris@49:       {
Chris@49:       arma_extra_debug_print("op_sort::apply(), dim = 1, generic");
Chris@49:       
Chris@49:       out.copy_size(X);
Chris@49:       
Chris@49:       const uword n_rows = out.n_rows;
Chris@49:       const uword n_cols = out.n_cols;
Chris@49:       
Chris@49:       podarray<eT> tmp_array(n_cols);
Chris@49:       
Chris@49:       for(uword row=0; row < n_rows; ++row)
Chris@49:         {
Chris@49:         op_sort::copy_row(tmp_array.memptr(), X, row);
Chris@49:         
Chris@49:         op_sort::direct_sort( tmp_array.memptr(), n_cols, sort_type );
Chris@49:         
Chris@49:         op_sort::copy_row(out, tmp_array.memptr(), row);
Chris@49:         }
Chris@49:       }
Chris@49:     }
Chris@49:   
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: //! @}