comparison armadillo-2.4.4/include/armadillo_bits/fn_sort_index.hpp @ 0:8b6102e2a9b0

Armadillo Library

+// Copyright (C) 2009-2010 NICTA (www.nicta.com.au)
+// Copyright (C) 2009-2010 Conrad Sanderson
+// 
+// This file is part of the Armadillo C++ library.
+// It is provided without any warranty of fitness
+// for any purpose. You can redistribute this file
+// and/or modify it under the terms of the GNU
+// Lesser General Public License (LGPL) as published
+// by the Free Software Foundation, either version 3
+// of the License or (at your option) any later version.
+// (see http://www.opensource.org/licenses for more info)
+
+
+//! \addtogroup fn_sort_index
+//! @{
+
+
+
+
+template<typename T1, typename T2>
+struct arma_sort_index_packet_ascend
+  {
+  T1 val;
+  T2 index;
+  };
+
+
+
+template<typename T1, typename T2>
+struct arma_sort_index_packet_descend
+  {
+  T1 val;
+  T2 index;
+  };
+
+
+
+template<typename T1, typename T2>
+inline
+bool
+operator< (const arma_sort_index_packet_ascend<T1,T2>& A, const arma_sort_index_packet_ascend<T1,T2>& B)
+  {
+  return A.val < B.val;
+  }
+
+
+
+template<typename T1, typename T2>
+inline
+bool
+operator< (const arma_sort_index_packet_descend<T1,T2>& A, const arma_sort_index_packet_descend<T1,T2>& B)
+  {
+  return A.val > B.val;
+  }
+
+
+
+template<typename umat_elem_type, typename packet_type, typename eT>
+void
+inline
+sort_index_helper(umat_elem_type* out_mem, std::vector<packet_type>& packet_vec, const eT* in_mem)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword n_elem = packet_vec.size();
+  
+  for(uword i=0; i<n_elem; ++i)
+    {
+    packet_vec[i].val   = in_mem[i];
+    packet_vec[i].index = i;
+    }
+  
+  std::sort( packet_vec.begin(), packet_vec.end() );
+  
+  for(uword i=0; i<n_elem; ++i)
+    {
+    out_mem[i] = packet_vec[i].index;
+    }
+  }
+
+
+
+template<typename T1>
+inline
+umat
+sort_index(const Base<typename T1::elem_type,T1>& X, const uword sort_type = 0)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  arma_type_check(( is_complex<eT>::value == true ));
+  
+  const unwrap<T1> tmp(X.get_ref());
+  const Mat<eT>& A = tmp.M;
+  
+  if(A.is_empty() == true)
+    {
+    return umat();
+    }
+  
+  arma_debug_check( (A.is_vec() == false), "sort_index(): currently only handles vectors");
+  
+  typedef typename umat::elem_type out_elem_type;
+  
+  umat out(A.n_rows, A.n_cols);
+  
+  if(sort_type == 0)
+    {
+    std::vector< arma_sort_index_packet_ascend<eT,out_elem_type> > packet_vec(A.n_elem);
+    
+    sort_index_helper(out.memptr(), packet_vec, A.mem);
+    }
+  else
+    {
+    std::vector< arma_sort_index_packet_descend<eT,out_elem_type> > packet_vec(A.n_elem);
+    
+    sort_index_helper(out.memptr(), packet_vec, A.mem);
+    }
+  
+  return out;
+  }
+
+
+//! @}