// SPDX-License-Identifier: Apache-2.0
// 
// Copyright 2008-2016 Conrad Sanderson (https://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// https://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------


//! \addtogroup op_toeplitz
//! @{



template<typename T1>
inline
void
op_toeplitz::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_toeplitz>& in)
  {
  arma_debug_sigprint();
  
  typedef typename T1::elem_type eT;
  
  const unwrap_check<T1>  tmp(in.m, out);
  const Mat<eT>& X      = tmp.M;
  
  arma_conform_check( ((X.is_vec() == false) && (X.is_empty() == false)), "toeplitz(): given object must be a vector" );
  
  const uword N     = X.n_elem;
  const eT*   X_mem = X.memptr();
  
  out.set_size(N,N);
  
  for(uword col=0; col < N; ++col)
    {
    eT* col_mem = out.colptr(col);
    
    uword i;
    
    i = col;
    for(uword row=0; row < col; ++row, --i) { col_mem[row] = X_mem[i]; }
    
    i = 0;
    for(uword row=col; row < N; ++row, ++i) { col_mem[row] = X_mem[i]; }      
    }
  }



template<typename T1>
inline
void
op_toeplitz_c::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_toeplitz_c>& in)
  {
  arma_debug_sigprint();
  
  typedef typename T1::elem_type eT;
  
  const unwrap_check<T1>  tmp(in.m, out);
  const Mat<eT>& X      = tmp.M;
  
  arma_conform_check( ((X.is_vec() == false) && (X.is_empty() == false)), "circ_toeplitz(): given object must be a vector" );
  
  const uword N     = X.n_elem;
  const eT*   X_mem = X.memptr();
  
  out.set_size(N,N);
  
  if(X.is_rowvec())
    {
    for(uword row=0; row < N; ++row)
      {
      uword i;
      
      i = row;
      for(uword col=0; col < row; ++col, --i)  { out.at(row,col) = X_mem[N-i]; }
      
      i = 0;
      for(uword col=row; col < N; ++col, ++i)  { out.at(row,col) = X_mem[i];   }
      }
    }
  else
    {
    for(uword col=0; col < N; ++col)
      {
      eT* col_mem = out.colptr(col);
      
      uword i;
      
      i = col;
      for(uword row=0; row < col; ++row, --i)  { col_mem[row] = X_mem[N-i]; }
      
      i = 0;
      for(uword row=col; row < N; ++row, ++i)  { col_mem[row] = X_mem[i];   }
      }
    }
  }



//! @}