text: // Copyright (C) 2009-2013 Conrad Sanderson
  // Copyright (C) 2009-2013 NICTA (www.nicta.com.au)
  // 
  // This Source Code Form is subject to the terms of the Mozilla Public
  // License, v. 2.0. If a copy of the MPL was not distributed with this
  // file, You can obtain one at http://mozilla.org/MPL/2.0/.
  
  
  //! \addtogroup fn_solve
  //! @{
  
  
  
  //! Solve a system of linear equations, i.e., A*X = B, where X is unknown.
  //! For a square matrix A, this function is conceptually the same as X = inv(A)*B,
  //! but is done more efficiently.
  //! The number of rows in A and B must be the same.
  //! B can be either a column vector or a matrix.
  //! This function will also try to provide approximate solutions
  //! to under-determined as well as over-determined systems (non-square A matrices).
  
  template<typename T1, typename T2>
  inline
  const Glue<T1, T2, glue_solve>
  solve
    (
    const Base<typename T1::elem_type,T1>& A,
    const Base<typename T1::elem_type,T2>& B,
    const bool slow = false,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    return Glue<T1, T2, glue_solve>(A.get_ref(), B.get_ref(), ((slow == false) ? 0 : 1) );
    }
  
  
  
  template<typename T1, typename T2>
  inline
  const Glue<T1, T2, glue_solve>
  solve
    (
    const Base<typename T1::elem_type,T1>& A,
    const Base<typename T1::elem_type,T2>& B,
    const char* method,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    const char sig = method[0];
    
    arma_debug_check( ((sig != 's') && (sig != 'f')), "solve(): unknown method specified" );
    
    return Glue<T1, T2, glue_solve>( A.get_ref(), B.get_ref(), ((sig == 'f') ? 0 : 1) );
    }
  
  
  
  template<typename T1, typename T2>
  inline
  const Glue<T1, T2, glue_solve_tr>
  solve
    (
    const Op<T1, op_trimat>& A,
    const Base<typename T1::elem_type,T2>& B,
    const bool slow = false,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(slow);
    arma_ignore(junk);
    
    return Glue<T1, T2, glue_solve_tr>(A.m, B.get_ref(), A.aux_uword_a);
    }
  
  
  
  template<typename T1, typename T2>
  inline
  const Glue<T1, T2, glue_solve_tr>
  solve
    (
    const Op<T1, op_trimat>& A,
    const Base<typename T1::elem_type,T2>& B,
    const char* method,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    const char sig = method[0];
    
    arma_debug_check( ((sig != 's') && (sig != 'f')), "solve(): unknown method specified" );
    
    return Glue<T1, T2, glue_solve_tr>(A.m, B.get_ref(), A.aux_uword_a);
    }
  
  
  
  template<typename T1, typename T2>
  inline
  bool
  solve
    (
           Mat<typename T1::elem_type>&    out,
    const Base<typename T1::elem_type,T1>& A,
    const Base<typename T1::elem_type,T2>& B,
    const bool slow = false,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    try
      {
      out = solve( A.get_ref(), B.get_ref(), slow );
      }
    catch(std::runtime_error&)
      {
      return false;
      }
    
    return true;
    }
  
  
  
  template<typename T1, typename T2>
  inline
  bool
  solve
    (
           Mat<typename T1::elem_type>&    out,
    const Base<typename T1::elem_type,T1>& A,
    const Base<typename T1::elem_type,T2>& B,
    const char* method,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    try
      {
      out = solve( A.get_ref(), B.get_ref(), method );
      }
    catch(std::runtime_error&)
      {
      return false;
      }
    
    return true;
    }
  
  
  
  //! @}
  