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_diagmat
Chris@49: //! @{
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1>
Chris@49: inline
Chris@49: void
Chris@49: op_diagmat::apply(Mat<typename T1::elem_type>& out, const Op<T1, op_diagmat>& X)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   typedef typename T1::elem_type eT;
Chris@49:   
Chris@49:   const Proxy<T1> P(X.m);
Chris@49:   
Chris@49:   const uword n_rows = P.get_n_rows();
Chris@49:   const uword n_cols = P.get_n_cols();
Chris@49:   
Chris@49:   const bool P_is_vec = (n_rows == 1) || (n_cols == 1);
Chris@49:   
Chris@49:   
Chris@49:   if(P.is_alias(out) == false)
Chris@49:     {
Chris@49:     if(P_is_vec)    // generate a diagonal matrix out of a vector
Chris@49:       {
Chris@49:       const uword N = (n_rows == 1) ? n_cols : n_rows;
Chris@49:       
Chris@49:       out.zeros(N, N);
Chris@49:       
Chris@49:       if(Proxy<T1>::prefer_at_accessor == false)
Chris@49:         {
Chris@49:         typename Proxy<T1>::ea_type P_ea = P.get_ea();
Chris@49:         
Chris@49:         for(uword i=0; i < N; ++i) { out.at(i,i) = P_ea[i]; }
Chris@49:         }
Chris@49:       else
Chris@49:         {
Chris@49:         if(n_rows == 1)
Chris@49:           {
Chris@49:           for(uword i=0; i < N; ++i) { out.at(i,i) = P.at(0,i); }
Chris@49:           }
Chris@49:         else
Chris@49:           {
Chris@49:           for(uword i=0; i < N; ++i) { out.at(i,i) = P.at(i,0); }
Chris@49:           }
Chris@49:         }
Chris@49:       }
Chris@49:     else   // generate a diagonal matrix out of a matrix
Chris@49:       {
Chris@49:       arma_debug_check( (n_rows != n_cols), "diagmat(): given matrix is not square" );
Chris@49:       
Chris@49:       out.zeros(n_rows, n_rows);
Chris@49:       
Chris@49:       for(uword i=0; i < n_rows; ++i) { out.at(i,i) = P.at(i,i); }
Chris@49:       }
Chris@49:     }
Chris@49:   else   // we have aliasing
Chris@49:     {
Chris@49:     if(P_is_vec)   // generate a diagonal matrix out of a vector
Chris@49:       {
Chris@49:       const uword N = (n_rows == 1) ? n_cols : n_rows;
Chris@49:       
Chris@49:       podarray<eT> tmp(N);
Chris@49:       eT* tmp_mem = tmp.memptr();
Chris@49:       
Chris@49:       if(Proxy<T1>::prefer_at_accessor == false)
Chris@49:         {
Chris@49:         typename Proxy<T1>::ea_type P_ea = P.get_ea();
Chris@49:         
Chris@49:         for(uword i=0; i < N; ++i) { tmp_mem[i] = P_ea[i]; }
Chris@49:         }
Chris@49:       else
Chris@49:         {
Chris@49:         if(n_rows == 1)
Chris@49:           {
Chris@49:           for(uword i=0; i < N; ++i) { tmp_mem[i] = P.at(0,i); }
Chris@49:           }
Chris@49:         else
Chris@49:           {
Chris@49:           for(uword i=0; i < N; ++i) { tmp_mem[i] = P.at(i,0); }
Chris@49:           }
Chris@49:         }
Chris@49:       
Chris@49:       out.zeros(N, N);
Chris@49:       
Chris@49:       for(uword i=0; i < N; ++i) { out.at(i,i) = tmp_mem[i]; }
Chris@49:       }
Chris@49:     else   // generate a diagonal matrix out of a matrix
Chris@49:       {
Chris@49:       arma_debug_check( (n_rows != n_cols), "diagmat(): given matrix is not square" );
Chris@49:       
Chris@49:       if( (Proxy<T1>::has_subview == false) && (Proxy<T1>::fake_mat == false) )
Chris@49:         {
Chris@49:         // NOTE: we have aliasing and it's not due to a subview, hence we're assuming that the output matrix already has the correct size
Chris@49:         
Chris@49:         for(uword i=0; i < n_rows; ++i)
Chris@49:           {
Chris@49:           const eT val = P.at(i,i);
Chris@49:           
Chris@49:           arrayops::inplace_set(out.colptr(i), eT(0), n_rows);
Chris@49:           
Chris@49:           out.at(i,i) = val;
Chris@49:           }
Chris@49:         }
Chris@49:       else
Chris@49:         {
Chris@49:         podarray<eT> tmp(n_rows);
Chris@49:         eT* tmp_mem = tmp.memptr();
Chris@49:         
Chris@49:         for(uword i=0; i < n_rows; ++i)  { tmp_mem[i] = P.at(i,i); }
Chris@49:         
Chris@49:         out.zeros(n_rows, n_rows);
Chris@49:         
Chris@49:         for(uword i=0; i < n_rows; ++i)  { out.at(i,i) = tmp_mem[i]; }
Chris@49:         }
Chris@49:       }
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //! @}