fn_accu.hpp

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00001 // Copyright (C) 2010 NICTA and the authors listed below
00002 // http://nicta.com.au
00003 // 
00004 // Authors:
00005 // - Conrad Sanderson (conradsand at ieee dot org)
00006 // 
00007 // This file is part of the Armadillo C++ library.
00008 // It is provided without any warranty of fitness
00009 // for any purpose. You can redistribute this file
00010 // and/or modify it under the terms of the GNU
00011 // Lesser General Public License (LGPL) as published
00012 // by the Free Software Foundation, either version 3
00013 // of the License or (at your option) any later version.
00014 // (see http://www.opensource.org/licenses for more info)
00015 
00016 
00017 //! \addtogroup fn_accu
00018 //! @{
00019 
00020 
00021 
00022 template<typename T1>
00023 arma_hot
00024 inline
00025 typename T1::elem_type
00026 accu_unwrap(const Base<typename T1::elem_type,T1>& X)
00027   {
00028   arma_extra_debug_sigprint();
00029   
00030   typedef typename T1::elem_type eT;
00031   
00032   const unwrap<T1>   tmp(X.get_ref());
00033   const Mat<eT>& A = tmp.M;
00034   
00035   const eT* A_mem = A.memptr();
00036   const u32 N     = A.n_elem;
00037   
00038   eT val1 = eT(0);
00039   eT val2 = eT(0);
00040   
00041   u32 i,j;
00042   
00043   for(i=0, j=1; j<N; i+=2, j+=2)
00044     {
00045     val1 += A_mem[i];
00046     val2 += A_mem[j];
00047     }
00048   
00049   if(i < N)
00050     {
00051     val1 += A_mem[i];
00052     }
00053   
00054   return val1 + val2;
00055   }
00056 
00057 
00058 
00059 template<typename T1>
00060 arma_hot
00061 inline
00062 typename T1::elem_type
00063 accu_proxy(const Base<typename T1::elem_type,T1>& X)
00064   {
00065   arma_extra_debug_sigprint();
00066   
00067   typedef typename T1::elem_type eT;
00068   
00069   const Proxy<T1> A(X.get_ref());
00070   
00071   const u32 N = A.n_elem;
00072   
00073   eT val = eT(0);
00074   
00075   for(u32 i=0; i<N; ++i)
00076     {
00077     val += A[i];
00078     }
00079   
00080   return val;
00081   }
00082 
00083 
00084 
00085 //! accumulate the elements of a matrix
00086 template<typename T1>
00087 arma_inline
00088 arma_warn_unused
00089 typename T1::elem_type
00090 accu(const Base<typename T1::elem_type,T1>& X)
00091   {
00092   arma_extra_debug_sigprint();
00093   
00094   return (is_Mat<T1>::value == true) ? accu_unwrap(X) : accu_proxy(X);
00095   }
00096 
00097 
00098 
00099 //! accumulate the elements of a cube
00100 template<typename T1>
00101 arma_hot
00102 arma_warn_unused
00103 inline
00104 typename T1::elem_type
00105 accu(const BaseCube<typename T1::elem_type,T1>& X)
00106   {
00107   arma_extra_debug_sigprint();
00108   
00109   typedef typename T1::elem_type eT;
00110   
00111   const ProxyCube<T1> A(X.get_ref());
00112   
00113   const u32 n_elem = A.n_elem;
00114   
00115   eT val = eT(0);
00116   
00117   for(u32 i=0; i<n_elem; ++i)
00118     {
00119     val += A[i];
00120     }
00121   
00122   return val;
00123   }
00124 
00125 
00126 
00127 //! accumulate the elements of a diagview
00128 template<typename eT>
00129 arma_pure
00130 arma_warn_unused
00131 inline
00132 eT
00133 accu(const diagview<eT>& X)
00134   {
00135   arma_extra_debug_sigprint();  
00136   
00137   const u32 n_elem = X.n_elem;
00138   eT val = eT(0);
00139   
00140   for(u32 i=0; i<n_elem; ++i)
00141     {
00142     val += X[i];
00143     }
00144   
00145   return val;
00146   }
00147 
00148 
00149 
00150 //! accumulate the elements of a subview (submatrix)
00151 template<typename eT>
00152 arma_pure
00153 arma_warn_unused
00154 inline
00155 eT
00156 accu(const subview<eT>& S)
00157   {
00158   arma_extra_debug_sigprint();  
00159   
00160   eT val = eT(0);
00161   
00162   for(u32 col=0; col<S.n_cols; ++col)
00163     {
00164     const eT* coldata = S.colptr(col);
00165     
00166     for(u32 row=0; row<S.n_rows; ++row)
00167       {
00168       val += coldata[row];
00169       }
00170     
00171     }
00172   
00173   return val;
00174   }
00175 
00176 
00177 
00178 //! accumulate the elements of a subview_row
00179 template<typename eT>
00180 arma_pure
00181 arma_warn_unused
00182 inline
00183 eT
00184 accu(const subview_row<eT>& S)
00185   {
00186   arma_extra_debug_sigprint();  
00187   
00188   const Mat<eT>& X = S.m;
00189   
00190   const u32 row       = S.aux_row1;
00191   const u32 start_col = S.aux_col1;
00192   const u32 end_col   = S.aux_col2;
00193   
00194   eT val = eT(0);
00195   
00196   for(u32 col=start_col; col<=end_col; ++col)
00197     {
00198     val += X.at(row,col);
00199     }
00200   
00201   return val;
00202   }
00203 
00204 
00205 
00206 //! accumulate the elements of a subview_col
00207 template<typename eT>
00208 arma_pure
00209 arma_warn_unused
00210 inline
00211 eT
00212 accu(const subview_col<eT>& S)
00213   {
00214   arma_extra_debug_sigprint();
00215   
00216   const eT* S_colptr = S.colptr(0);
00217   const u32 n_rows   = S.n_rows;
00218   
00219   eT val = eT(0);
00220   
00221   for(u32 row=0; row<n_rows; ++row)
00222     {
00223     val += S_colptr[row];
00224     }
00225   
00226   return val;
00227   }
00228 
00229 
00230 
00231 //! @}