max@0: // Copyright (C) 2009-2011 NICTA (www.nicta.com.au)
max@0: // Copyright (C) 2009-2011 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 op_median
max@0: //! @{
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: arma_inline
max@0: eT
max@0: op_median::robust_mean(const eT A, const eT B)
max@0:   {
max@0:   return A + (B - A)/eT(2);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! find the median value of a std::vector (contents is modified)
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_median::direct_median(std::vector<eT>& X)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword n_elem = X.size();
max@0:   const uword half   = n_elem/2;
max@0:   
max@0:   std::sort(X.begin(), X.end());
max@0:   
max@0:   if((n_elem % 2) == 0)
max@0:     {
max@0:     return op_median::robust_mean(X[half-1], X[half]);
max@0:     }
max@0:   else
max@0:     {
max@0:     return X[half];
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_median::direct_median(const eT* X, const uword n_elem)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   std::vector<eT> tmp(X, X+n_elem);
max@0:   
max@0:   return op_median::direct_median(tmp);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_median::direct_median(const subview<eT>& X)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword X_n_elem = X.n_elem;
max@0:   
max@0:   std::vector<eT> tmp(X_n_elem);
max@0:   
max@0:   for(uword i=0; i<X_n_elem; ++i)
max@0:     {
max@0:     tmp[i] = X[i];
max@0:     }
max@0:   
max@0:   return op_median::direct_median(tmp);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_median::direct_median(const diagview<eT>& X)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword X_n_elem = X.n_elem;
max@0:   
max@0:   std::vector<eT> tmp(X_n_elem);
max@0:   
max@0:   for(uword i=0; i<X_n_elem; ++i)
max@0:     {
max@0:     tmp[i] = X[i];
max@0:     }
max@0:   
max@0:   return op_median::direct_median(tmp);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! \brief
max@0: //! For each row or for each column, find the median value.
max@0: //! The result is stored in a dense matrix that has either one column or one row.
max@0: //! The dimension, for which the medians are found, is set via the median() function.
max@0: template<typename T1>
max@0: inline
max@0: void
max@0: op_median::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_median>& in)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   typedef typename T1::elem_type eT;
max@0:   
max@0:   const unwrap_check<T1> tmp(in.m, out);
max@0:   const Mat<eT>&     X = tmp.M;
max@0:   
max@0:   const uword X_n_rows = X.n_rows;
max@0:   const uword X_n_cols = X.n_cols;
max@0:   
max@0:   const uword dim = in.aux_uword_a;
max@0:   arma_debug_check( (dim > 1), "median(): incorrect usage. dim must be 0 or 1");
max@0:   
max@0:   if(dim == 0)  // in each column
max@0:     {
max@0:     arma_extra_debug_print("op_median::apply(), dim = 0");
max@0:     
max@0:     arma_debug_check( (X_n_rows == 0), "median(): given object has zero rows" );
max@0: 
max@0:     out.set_size(1, X_n_cols);
max@0:     
max@0:     std::vector<eT> tmp_vec(X_n_rows);
max@0:       
max@0:     for(uword col=0; col<X_n_cols; ++col)
max@0:       {
max@0:       const eT* colmem = X.colptr(col);
max@0:       
max@0:       for(uword row=0; row<X_n_rows; ++row)
max@0:         {
max@0:         tmp_vec[row] = colmem[row];
max@0:         }
max@0:       
max@0:       out[col] = op_median::direct_median(tmp_vec);
max@0:       }
max@0:     }
max@0:   else
max@0:   if(dim == 1)  // in each row
max@0:     {
max@0:     arma_extra_debug_print("op_median::apply(), dim = 1");
max@0:     
max@0:     arma_debug_check( (X_n_cols == 0), "median(): given object has zero columns" );
max@0: 
max@0:     out.set_size(X_n_rows, 1);
max@0:     
max@0:     std::vector<eT> tmp_vec(X_n_cols);
max@0:       
max@0:     for(uword row=0; row<X_n_rows; ++row)
max@0:       {
max@0:       for(uword col=0; col<X_n_cols; ++col)
max@0:         {
max@0:         tmp_vec[col] = X.at(row,col);
max@0:         }
max@0:       
max@0:       out[row] =  op_median::direct_median(tmp_vec);
max@0:       }
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: arma_inline
max@0: std::complex<T>
max@0: op_median::robust_mean(const std::complex<T>& A, const std::complex<T>& B)
max@0:   {
max@0:   return A + (B - A)/T(2);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: void
max@0: op_median::direct_cx_median_index
max@0:   (
max@0:   uword& out_index1, 
max@0:   uword& out_index2, 
max@0:   std::vector< arma_cx_median_packet<T> >& X
max@0:   )
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword n_elem = X.size();
max@0:   const uword half   = n_elem/2;
max@0:   
max@0:   std::sort(X.begin(), X.end());
max@0:   
max@0:   if((n_elem % 2) == 0)
max@0:     {
max@0:     out_index1 = X[half-1].index;
max@0:     out_index2 = X[half  ].index;
max@0:     }
max@0:   else
max@0:     {
max@0:     out_index1 = X[half].index;
max@0:     out_index2 = out_index1;
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: void
max@0: op_median::direct_cx_median_index
max@0:   (
max@0:   uword& out_index1, 
max@0:   uword& out_index2, 
max@0:   const std::complex<T>* X, 
max@0:   const uword n_elem
max@0:   )
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   std::vector< arma_cx_median_packet<T> > tmp(n_elem);
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     tmp[i].val   = std::abs(X[i]);
max@0:     tmp[i].index = i;
max@0:     }
max@0:   
max@0:   op_median::direct_cx_median_index(out_index1, out_index2, tmp);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: void
max@0: op_median::direct_cx_median_index
max@0:   (
max@0:   uword& out_index1, 
max@0:   uword& out_index2, 
max@0:   const subview< std::complex<T> >&X
max@0:   )
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword n_elem = X.n_elem;
max@0:   
max@0:   std::vector< arma_cx_median_packet<T> > tmp(n_elem);
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     tmp[i].val   = std::abs(X[i]);
max@0:     tmp[i].index = i;
max@0:     }
max@0:   
max@0:   op_median::direct_cx_median_index(out_index1, out_index2, tmp);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: void
max@0: op_median::direct_cx_median_index
max@0:   (
max@0:   uword& out_index1, 
max@0:   uword& out_index2, 
max@0:   const diagview< std::complex<T> >&X
max@0:   )
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword n_elem = X.n_elem;
max@0:   
max@0:   std::vector< arma_cx_median_packet<T> > tmp(n_elem);
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     tmp[i].val   = std::abs(X[i]);
max@0:     tmp[i].index = i;
max@0:     }
max@0:   
max@0:   op_median::direct_cx_median_index(out_index1, out_index2, tmp);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! Implementation for complex numbers
max@0: template<typename T, typename T1>
max@0: inline
max@0: void
max@0: op_median::apply(Mat< std::complex<T> >& out, const Op<T1,op_median>& in)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   typedef typename std::complex<T> eT;
max@0:   
max@0:   arma_type_check(( is_same_type<eT, typename T1::elem_type>::value == false ));
max@0:   
max@0:   const unwrap_check<T1> tmp(in.m, out);
max@0:   const Mat<eT>&     X = tmp.M;
max@0:   
max@0:   const uword X_n_rows = X.n_rows;
max@0:   const uword X_n_cols = X.n_cols;
max@0:   
max@0:   const uword dim = in.aux_uword_a;
max@0:   arma_debug_check( (dim > 1), "median(): incorrect usage. dim must be 0 or 1");
max@0:   
max@0:   if(dim == 0)  // in each column
max@0:     {
max@0:     arma_extra_debug_print("op_median::apply(), dim = 0");
max@0:     
max@0:     arma_debug_check( (X_n_rows == 0), "median(): given object has zero rows" );
max@0: 
max@0:     out.set_size(1, X_n_cols);
max@0:     
max@0:     std::vector< arma_cx_median_packet<T> > tmp_vec(X_n_rows);
max@0:     
max@0:     for(uword col=0; col<X_n_cols; ++col)
max@0:       {
max@0:       const eT* colmem = X.colptr(col);
max@0:       
max@0:       for(uword row=0; row<X_n_rows; ++row)
max@0:         {
max@0:         tmp_vec[row].val   = std::abs(colmem[row]);
max@0:         tmp_vec[row].index = row;
max@0:         }
max@0:       
max@0:       uword index1;
max@0:       uword index2;
max@0:       op_median::direct_cx_median_index(index1, index2, tmp_vec);
max@0:         
max@0:       out[col] = op_median::robust_mean(colmem[index1], colmem[index2]);
max@0:       }
max@0:     }
max@0:   else
max@0:   if(dim == 1)  // in each row
max@0:     {
max@0:     arma_extra_debug_print("op_median::apply(), dim = 1");
max@0:     
max@0:     arma_debug_check( (X_n_cols == 0), "median(): given object has zero columns" );
max@0: 
max@0:     out.set_size(X_n_rows, 1);
max@0:     
max@0:     std::vector< arma_cx_median_packet<T> > tmp_vec(X_n_cols);
max@0:     
max@0:     for(uword row=0; row<X_n_rows; ++row)
max@0:       {
max@0:       for(uword col=0; col<X_n_cols; ++col)
max@0:         {
max@0:         tmp_vec[col].val   = std::abs(X.at(row,col));
max@0:         tmp_vec[row].index = col;
max@0:         }
max@0:       
max@0:       uword index1;
max@0:       uword index2;
max@0:       op_median::direct_cx_median_index(index1, index2, tmp_vec);
max@0:       
max@0:       out[row] = op_median::robust_mean( X.at(row,index1), X.at(row,index2) );
max@0:       }
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! @}
max@0: