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_prod
max@0: //! @{
max@0: 
max@0: //! \brief
max@0: //! Immediate product of elements of a matrix along a specified dimension (either rows or columns).
max@0: //! The result is stored in a dense matrix that has either one column or one row.
max@0: //! See the prod() function for more details.
max@0: template<typename T1>
max@0: inline
max@0: void
max@0: op_prod::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_prod>& in)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   typedef typename T1::elem_type eT;
max@0:   
max@0:   const uword dim = in.aux_uword_a;
max@0:   arma_debug_check( (dim > 1), "prod(): incorrect usage. dim must be 0 or 1");
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:   if(dim == 0)  // traverse across rows (i.e. find the product in each column)
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] = arrayops::product(X.colptr(col), X_n_rows);
max@0:       }
max@0:     }
max@0:   else  // traverse across columns (i.e. find the product in each row)
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:       eT val = eT(1);
max@0:       
max@0:       for(uword col=0; col<X_n_cols; ++col)
max@0:         {
max@0:         val *= X.at(row,col);
max@0:         }
max@0:       
max@0:       out_mem[row] = val;
max@0:       }
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! @}