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_diagmat
max@0: //! @{
max@0: 
max@0: 
max@0: 
max@0: template<typename T1>
max@0: inline
max@0: void
max@0: op_diagmat::apply(Mat<typename T1::elem_type>& out, const Op<T1, op_diagmat>& X)
max@0:   {
max@0:   arma_extra_debug_sigprint();
max@0:   
max@0:   typedef typename T1::elem_type eT;
max@0:   
max@0:   const unwrap<T1>   tmp(X.m);
max@0:   const Mat<eT>& A = tmp.M;
max@0:   
max@0:   if(A.is_vec() == true)
max@0:     {
max@0:     // generate a diagonal matrix out of a vector
max@0:     
max@0:     const uword N     = A.n_elem;
max@0:     const eT* A_mem = A.memptr();
max@0:     
max@0:     if(&out != &A)
max@0:       {
max@0:       // no aliasing
max@0:       out.zeros(N,N);
max@0:       
max@0:       for(uword i=0; i<N; ++i)
max@0:         {
max@0:         out.at(i,i) = A_mem[i];
max@0:         }
max@0:       }
max@0:     else
max@0:       {
max@0:       // aliasing
max@0:       
max@0:       const podarray<eT> tmp(A_mem, N);
max@0:       
max@0:       const eT* tmp_mem = tmp.memptr();
max@0:       
max@0:       out.zeros(N,N);
max@0:       
max@0:       for(uword i=0; i<N; ++i)
max@0:         {
max@0:         out.at(i,i) = tmp_mem[i];
max@0:         }
max@0:       }
max@0:     }
max@0:   else
max@0:     {
max@0:     // generate a diagonal matrix out of a matrix
max@0:     
max@0:     arma_debug_check( (A.is_square() == false), "diagmat(): given matrix is not square" );
max@0:     
max@0:     const uword N = A.n_rows;
max@0:     
max@0:     if(&out != &A)
max@0:       {
max@0:       // no aliasing
max@0:       
max@0:       out.zeros(N,N);
max@0:       
max@0:       for(uword i=0; i<N; ++i)
max@0:         {
max@0:         out.at(i,i) = A.at(i,i);
max@0:         }
max@0:       }
max@0:     else
max@0:       {
max@0:       // aliasing
max@0:       
max@0:       for(uword i=0; i<N; ++i)
max@0:         {
max@0:         eT* colptr = out.colptr(i);
max@0:         
max@0:         // clear above the diagonal
max@0:         arrayops::inplace_set(colptr, eT(0), i);
max@0:         
max@0:         // clear below the diagonal
max@0:         arrayops::inplace_set(colptr+(i+1), eT(0), N-1-i);
max@0:         }
max@0:       }
max@0:     }
max@0:   }
max@0: 
max@0: 
max@0: 
max@0: //! @}