max@0: // Copyright (C) 2008-2011 NICTA (www.nicta.com.au)
max@0: // Copyright (C) 2008-2011 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_min
max@0: //! @{
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: arma_pure
max@0: inline 
max@0: eT
max@0: op_min::direct_min(const eT* const X, const uword n_elem)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   eT min_val = priv::most_pos<eT>();
max@0:   
max@0:   uword i,j;
max@0:   
max@0:   for(i=0, j=1; j<n_elem; i+=2, j+=2)
max@0:     {
max@0:     const eT X_i = X[i];
max@0:     const eT X_j = X[j];
max@0:     
max@0:     if(X_i < min_val)
max@0:       {
max@0:       min_val = X_i;
max@0:       }
max@0:     
max@0:     if(X_j < min_val)
max@0:       {
max@0:       min_val = X_j;
max@0:       }
max@0:     }
max@0:   
max@0:   
max@0:   if(i < n_elem)
max@0:     {
max@0:     const eT X_i = X[i];
max@0:     
max@0:     if(X_i < min_val)
max@0:       {
max@0:       min_val = X_i;
max@0:       }
max@0:     }
max@0:   
max@0:   return min_val;
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_min::direct_min(const eT* const X, const uword n_elem, uword& index_of_min_val)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   eT min_val = priv::most_pos<eT>();
max@0:   
max@0:   uword best_index = 0;
max@0:   
max@0:   uword i,j;
max@0:   
max@0:   for(i=0, j=1; j<n_elem; i+=2, j+=2)
max@0:     {
max@0:     const eT X_i = X[i];
max@0:     const eT X_j = X[j];
max@0:     
max@0:     if(X_i < min_val)
max@0:       {
max@0:       min_val    = X_i;
max@0:       best_index = i;
max@0:       }
max@0:     
max@0:     if(X_j < min_val)
max@0:       {
max@0:       min_val    = X_j;
max@0:       best_index = j;
max@0:       }
max@0:     }
max@0:   
max@0:   
max@0:   if(i < n_elem)
max@0:     {
max@0:     const eT X_i = X[i];
max@0:     
max@0:     if(X_i < min_val)
max@0:       {
max@0:       min_val    = X_i;
max@0:       best_index = i;
max@0:       }
max@0:     }
max@0:   
max@0:   index_of_min_val = best_index;
max@0:   
max@0:   return min_val;
max@0:   }  
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_min::direct_min(const Mat<eT>& X, const uword row)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword X_n_cols = X.n_cols;
max@0:   
max@0:   eT min_val = priv::most_pos<eT>();
max@0:   
max@0:   for(uword col=0; col<X_n_cols; ++col)
max@0:     {
max@0:     const eT tmp_val = X.at(row,col);
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       }
max@0:     }
max@0:   
max@0:   return min_val;
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_min::direct_min(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:   eT min_val = priv::most_pos<eT>();
max@0:   
max@0:   for(uword i=0; i<X_n_elem; ++i)
max@0:     {
max@0:     eT tmp_val = X[i];
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       }
max@0:     }
max@0:   
max@0:   return min_val;
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename eT>
max@0: inline 
max@0: eT
max@0: op_min::direct_min(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:   eT min_val = priv::most_pos<eT>();;
max@0:   
max@0:   for(uword i=0; i<X_n_elem; ++i)
max@0:     {
max@0:     eT tmp_val = X[i];
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       }
max@0:     }
max@0:   
max@0:   return min_val;
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! \brief
max@0: //! For each row or for each column, find the minimum 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 minima are found, is set via the min() function.
max@0: template<typename T1>
max@0: inline void op_min::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_min>& 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 dim = in.aux_uword_a;
max@0:   arma_debug_check( (dim > 1), "min(): incorrect usage. dim must be 0 or 1");
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:   if(dim == 0)  // min in each column
max@0:     {
max@0:     arma_extra_debug_print("op_min::apply(), dim = 0");
max@0:     
max@0:     arma_debug_check( (X_n_rows == 0), "min(): given object has zero rows" );
max@0: 
max@0:     out.set_size(1, X_n_cols);
max@0:     
max@0:     eT* out_mem = out.memptr();
max@0:     
max@0:     for(uword col=0; col<X_n_cols; ++col)
max@0:       {
max@0:       out_mem[col] = op_min::direct_min( X.colptr(col), X_n_rows );
max@0:       }
max@0:     }
max@0:   else
max@0:   if(dim == 1)  // min in each row
max@0:     {
max@0:     arma_extra_debug_print("op_min::apply(), dim = 1");
max@0:     
max@0:     arma_debug_check( (X_n_cols == 0), "min(): given object has zero columns" );
max@0: 
max@0:     out.set_size(X_n_rows, 1);
max@0:     
max@0:     eT* out_mem = out.memptr();
max@0:     
max@0:     for(uword row=0; row<X_n_rows; ++row)
max@0:       {
max@0:       out_mem[row] = op_min::direct_min( X, row );
max@0:       }
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: std::complex<T>
max@0: op_min::direct_min(const std::complex<T>* const X, const uword n_elem)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   uword index   = 0;
max@0:   T   min_val = priv::most_pos<T>();
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     const T tmp_val = std::abs(X[i]);
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       index   = i;
max@0:       }
max@0:     }
max@0:   
max@0:   return X[index];
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: std::complex<T>
max@0: op_min::direct_min(const std::complex<T>* const X, const uword n_elem, uword& index_of_min_val)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   uword index   = 0;
max@0:   T   min_val = priv::most_pos<T>();
max@0:   
max@0:   for(uword i=0; i<n_elem; ++i)
max@0:     {
max@0:     const T tmp_val = std::abs(X[i]);
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       index   = i;
max@0:       }
max@0:     }
max@0:   
max@0:   index_of_min_val = index;
max@0:   
max@0:   return X[index];
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: std::complex<T>
max@0: op_min::direct_min(const Mat< std::complex<T> >& X, const uword row)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword X_n_cols = X.n_cols;
max@0:   
max@0:   uword index   = 0;
max@0:   T   min_val = priv::most_pos<T>();
max@0:   
max@0:   for(uword col=0; col<X_n_cols; ++col)
max@0:     {
max@0:     const T tmp_val = std::abs(X.at(row,col));
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       index   = col;
max@0:       }
max@0:     }
max@0:   
max@0:   return X.at(row,index);
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: std::complex<T>
max@0: op_min::direct_min(const subview< std::complex<T> >& X)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword X_n_elem = X.n_elem;
max@0:         uword index    = 0;
max@0:         T   min_val  = priv::most_pos<T>();
max@0:   
max@0:   for(uword i=0; i<X_n_elem; ++i)
max@0:     {
max@0:     const T tmp_val = std::abs(X[i]);
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       index   = i;
max@0:       }
max@0:     }
max@0:   
max@0:   return X[index];
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: template<typename T>
max@0: inline 
max@0: std::complex<T>
max@0: op_min::direct_min(const diagview< std::complex<T> >& X)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   const uword X_n_elem = X.n_elem;
max@0:         uword index    = 0;
max@0:         T   min_val  = priv::most_pos<T>();
max@0:   
max@0:   for(uword i=0; i<X_n_elem; ++i)
max@0:     {
max@0:     const T tmp_val = std::abs(X[i]);
max@0:     
max@0:     if(tmp_val < min_val)
max@0:       {
max@0:       min_val = tmp_val;
max@0:       index   = i;
max@0:       }
max@0:     }
max@0:   
max@0:   return X[index];
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! @}