text: // SPDX-License-Identifier: Apache-2.0
  // 
  // Copyright 2008-2016 Conrad Sanderson (http://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
  // http://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_cumsum
  //! @{
  
  
  
  template<typename eT>
  inline
  void
  op_cumsum::apply_noalias(Mat<eT>& out, const Mat<eT>& X, const uword dim)
    {
    arma_extra_debug_sigprint();
    
    uword n_rows = X.n_rows;
    uword n_cols = X.n_cols;
    
    out.set_size(n_rows,n_cols);
    
    if(out.n_elem == 0)  { return; }
    
    if(dim == 0)
      {
      if(n_cols == 1)
        {
        const eT*   X_mem =   X.memptr();
              eT* out_mem = out.memptr();
        
        eT acc = eT(0);
        
        for(uword row=0; row < n_rows; ++row)
          {
          acc += X_mem[row];
          
          out_mem[row] = acc;
          }
        }
      else
        {
        for(uword col=0; col < n_cols; ++col)
          {
          const eT*   X_colmem =   X.colptr(col);
                eT* out_colmem = out.colptr(col);
          
          eT acc = eT(0);
          
          for(uword row=0; row < n_rows; ++row)
            {
            acc += X_colmem[row];
            
            out_colmem[row] = acc;
            }
          }
        }
      }
    else
    if(dim == 1)
      {
      if(n_rows == 1)
        {
        const eT*   X_mem =   X.memptr();
              eT* out_mem = out.memptr();
        
        eT acc = eT(0);
        
        for(uword col=0; col < n_cols; ++col)
          {
          acc += X_mem[col];
          
          out_mem[col] = acc;
          }
        }
      else
        {
        if(n_cols > 0)
          {
          arrayops::copy( out.colptr(0), X.colptr(0), n_rows );
          
          for(uword col=1; col < n_cols; ++col)
            {
            const eT* out_colmem_prev = out.colptr(col-1);
                  eT* out_colmem      = out.colptr(col  );
            const eT*   X_colmem      =   X.colptr(col  );
            
            for(uword row=0; row < n_rows; ++row)
              {
              out_colmem[row] = out_colmem_prev[row] + X_colmem[row];
              }
            }
          }
        }
      }
    }
  
  
  
  template<typename T1>
  inline
  void
  op_cumsum::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_cumsum>& in)
    {
    arma_extra_debug_sigprint();
    
    typedef typename T1::elem_type eT;
    
    const uword dim = in.aux_uword_a;
    
    arma_debug_check( (dim > 1), "cumsum(): parameter 'dim' must be 0 or 1" );
    
    const quasi_unwrap<T1> U(in.m);
    
    if(U.is_alias(out))
      {
      Mat<eT> tmp;
      
      op_cumsum::apply_noalias(tmp, U.M, dim);
      
      out.steal_mem(tmp);
      }
    else
      {
      op_cumsum::apply_noalias(out, U.M, dim);
      }
    }
  
  
  
  template<typename T1>
  inline
  void
  op_cumsum_vec::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_cumsum_vec>& in)
    {
    arma_extra_debug_sigprint();
    
    typedef typename T1::elem_type eT;
    
    const quasi_unwrap<T1> U(in.m);
    
    const uword dim = (T1::is_xvec) ? uword(U.M.is_rowvec() ? 1 : 0) : uword((T1::is_row) ? 1 : 0);
    
    if(U.is_alias(out))
      {
      Mat<eT> tmp;
      
      op_cumsum::apply_noalias(tmp, U.M, dim);
      
      out.steal_mem(tmp);
      }
    else
      {
      op_cumsum::apply_noalias(out, U.M, dim);
      }
    }
  
  
  
  //! @}
  
  