Chris@49: // Copyright (C) 2009-2011 NICTA (www.nicta.com.au)
Chris@49: // Copyright (C) 2009-2011 Conrad Sanderson
Chris@49: // 
Chris@49: // This Source Code Form is subject to the terms of the Mozilla Public
Chris@49: // License, v. 2.0. If a copy of the MPL was not distributed with this
Chris@49: // file, You can obtain one at http://mozilla.org/MPL/2.0/.
Chris@49: 
Chris@49: 
Chris@49: //! \addtogroup fn_solve
Chris@49: //! @{
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //! Solve a system of linear equations, i.e., A*X = B, where X is unknown.
Chris@49: //! For a square matrix A, this function is conceptually the same as X = inv(A)*B,
Chris@49: //! but is done more efficiently.
Chris@49: //! The number of rows in A and B must be the same.
Chris@49: //! B can be either a column vector or a matrix.
Chris@49: //! This function will also try to provide approximate solutions
Chris@49: //! to under-determined as well as over-determined systems (non-square A matrices).
Chris@49: 
Chris@49: template<typename T1, typename T2>
Chris@49: inline
Chris@49: const Glue<T1, T2, glue_solve>
Chris@49: solve
Chris@49:   (
Chris@49:   const Base<typename T1::elem_type,T1>& A,
Chris@49:   const Base<typename T1::elem_type,T2>& B,
Chris@49:   const bool slow = false,
Chris@49:   const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
Chris@49:   )
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   arma_ignore(junk);
Chris@49:   
Chris@49:   return Glue<T1, T2, glue_solve>(A.get_ref(), B.get_ref(), ((slow == false) ? 0 : 1) );
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1, typename T2>
Chris@49: inline
Chris@49: const Glue<T1, T2, glue_solve_tr>
Chris@49: solve
Chris@49:   (
Chris@49:   const Op<T1, op_trimat>& A,
Chris@49:   const Base<typename T1::elem_type,T2>& B,
Chris@49:   const bool slow = false,
Chris@49:   const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
Chris@49:   )
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   arma_ignore(slow);
Chris@49:   arma_ignore(junk);
Chris@49:   
Chris@49:   return Glue<T1, T2, glue_solve_tr>(A.m, B.get_ref(), A.aux_uword_a);
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1, typename T2>
Chris@49: inline
Chris@49: bool
Chris@49: solve
Chris@49:   (
Chris@49:          Mat<typename T1::elem_type>&    out,
Chris@49:   const Base<typename T1::elem_type,T1>& A,
Chris@49:   const Base<typename T1::elem_type,T2>& B,
Chris@49:   const bool slow = false,
Chris@49:   const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
Chris@49:   )
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   arma_ignore(junk);
Chris@49:   
Chris@49:   try
Chris@49:     {
Chris@49:     out = solve( A.get_ref(), B.get_ref(), slow );
Chris@49:     }
Chris@49:   catch(std::runtime_error&)
Chris@49:     {
Chris@49:     return false;
Chris@49:     }
Chris@49:   
Chris@49:   return true;
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //! @}