operator_minus.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 operator_minus
00018 //! @{
00019 
00020 
00021 
00022 //! unary -
00023 template<typename T1>
00024 arma_inline
00025 const eOp<T1, eop_neg>
00026 operator-
00027 (const Base<typename T1::elem_type,T1>& X)
00028   {
00029   arma_extra_debug_sigprint();
00030   
00031   return eOp<T1,eop_neg>(X.get_ref());
00032   }
00033 
00034 
00035 
00036 //! cancellation of two consecutive negations: -(-T1)
00037 template<typename T1>
00038 arma_inline
00039 const T1&
00040 operator-
00041 (const eOp<T1, eop_neg>& X)
00042   {
00043   arma_extra_debug_sigprint();
00044   
00045   return X.m;
00046   }
00047 
00048 
00049 
00050 //! Base - scalar
00051 template<typename T1>
00052 arma_inline
00053 const eOp<T1, eop_scalar_minus_post>
00054 operator-
00055   (
00056   const Base<typename T1::elem_type,T1>& X,
00057   const typename T1::elem_type           k
00058   )
00059   {
00060   arma_extra_debug_sigprint();
00061   
00062   return eOp<T1, eop_scalar_minus_post>(X.get_ref(), k);
00063   }
00064 
00065 
00066 
00067 //! scalar - Base
00068 template<typename T1>
00069 arma_inline
00070 const eOp<T1, eop_scalar_minus_pre>
00071 operator-
00072   (
00073   const typename T1::elem_type           k,
00074   const Base<typename T1::elem_type,T1>& X
00075   )
00076   {
00077   arma_extra_debug_sigprint();
00078   
00079   return eOp<T1, eop_scalar_minus_pre>(X.get_ref(), k);
00080   }
00081 
00082 
00083 
00084 //! non-complex Base - complex scalar (experimental)
00085 template<typename T1>
00086 arma_inline
00087 Mat<typename std::complex<typename T1::pod_type> >
00088 operator-
00089   (
00090   const Base<typename T1::pod_type, T1>&     X,
00091   const std::complex<typename T1::pod_type>& k
00092   )
00093   {
00094   arma_extra_debug_sigprint();
00095   
00096   typedef typename std::complex<typename T1::pod_type> eT;
00097   typedef typename T1::pod_type                         T;
00098   
00099   const Proxy<T1> A(X.get_ref());
00100   
00101   Mat<eT> out(A.n_rows, A.n_cols);
00102   
00103   const u32 n_elem  = A.n_elem;
00104         eT* out_mem = out.memptr();
00105   
00106   for(u32 i=0; i<n_elem; ++i)
00107     {
00108     out_mem[i] = A[i] - k;
00109     }
00110   
00111   return out;
00112   }
00113 
00114 
00115 
00116 //! complex scalar - non-complex Base (experimental)
00117 template<typename T1>
00118 arma_inline
00119 Mat<typename std::complex<typename T1::pod_type> >
00120 operator-
00121   (
00122   const std::complex<typename T1::pod_type>& k,
00123   const Base<typename T1::pod_type, T1>&     X
00124   )
00125   {
00126   arma_extra_debug_sigprint();
00127   
00128   typedef typename std::complex<typename T1::pod_type> eT;
00129   typedef typename T1::pod_type                         T;
00130   
00131   const Proxy<T1> A(X.get_ref());
00132   
00133   Mat<eT> out(A.n_rows, A.n_cols);
00134   
00135   const u32 n_elem  = A.n_elem;
00136         eT* out_mem = out.memptr();
00137   
00138   for(u32 i=0; i<n_elem; ++i)
00139     {
00140     out_mem[i] = k - A[i];
00141     }
00142   
00143   return out;
00144   }
00145 
00146 
00147 
00148 //! subtraction of Base objects with same element type
00149 template<typename T1, typename T2>
00150 arma_inline
00151 const eGlue<T1, T2, eglue_minus>
00152 operator-
00153   (
00154   const Base<typename T1::elem_type,T1>& X,
00155   const Base<typename T1::elem_type,T2>& Y
00156   )
00157   {
00158   arma_extra_debug_sigprint();
00159   
00160   return eGlue<T1, T2, eglue_minus>(X.get_ref(), Y.get_ref());
00161   }
00162 
00163 
00164 
00165 //! subtraction of Base objects with different element types
00166 template<typename T1, typename T2>
00167 arma_inline
00168 Mat<typename promote_type<typename T1::elem_type, typename T2::elem_type>::result>
00169 operator-
00170   (
00171   const Base< typename force_different_type<typename T1::elem_type, typename T2::elem_type>::T1_result, T1>& X,
00172   const Base< typename force_different_type<typename T1::elem_type, typename T2::elem_type>::T2_result, T2>& Y
00173   )
00174   {
00175   arma_extra_debug_sigprint();
00176   
00177   typedef typename T1::elem_type eT1;
00178   typedef typename T2::elem_type eT2;
00179   
00180   typedef typename promote_type<eT1,eT2>::result out_eT;
00181   
00182   promote_type<eT1,eT2>::check();
00183   
00184   const Proxy<T1> A(X.get_ref());
00185   const Proxy<T2> B(Y.get_ref());
00186   
00187   arma_debug_assert_same_size(A, B, "matrix subtraction");
00188   
00189   Mat<out_eT> out(A.n_rows, A.n_cols);
00190 
00191         out_eT* out_mem = out.memptr();
00192   const u32     n_elem  = out.n_elem;
00193   
00194   for(u32 i=0; i<n_elem; ++i)
00195     {
00196     out_mem[i] = upgrade_val<eT1,eT2>::apply(A[i]) - upgrade_val<eT1,eT2>::apply(B[i]);
00197     }
00198   
00199   return out;
00200   }
00201 
00202 
00203 
00204 //! @}