text: // Copyright (C) 2008-2011 Conrad Sanderson
  // Copyright (C) 2008-2011 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_lu
  //! @{
  
  
  
  //! immediate lower upper decomposition, permutation info is embedded into L (similar to Matlab/Octave)
  template<typename T1>
  inline
  bool
  lu
    (
           Mat<typename T1::elem_type>&    L,
           Mat<typename T1::elem_type>&    U,
    const Base<typename T1::elem_type,T1>& X,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    arma_debug_check( (&L == &U), "lu(): L and U are the same object");
    
    const bool status = auxlib::lu(L, U, X);
    
    if(status == false)
      {
      L.reset();
      U.reset();
      arma_bad("lu(): failed to converge", false);
      }
    
    return status;
    }
  
  
  
  //! immediate lower upper decomposition, also providing the permutation matrix
  template<typename T1>
  inline
  bool
  lu
    (
           Mat<typename T1::elem_type>&    L,
           Mat<typename T1::elem_type>&    U, 
           Mat<typename T1::elem_type>&    P,
    const Base<typename T1::elem_type,T1>& X,
    const typename arma_blas_type_only<typename T1::elem_type>::result* junk = 0
    )
    {
    arma_extra_debug_sigprint();
    arma_ignore(junk);
    
    arma_debug_check( ( (&L == &U) || (&L == &P) || (&U == &P) ), "lu(): two or more output objects are the same object");
    
    const bool status = auxlib::lu(L, U, P, X);
    
    if(status == false)
      {
      L.reset();
      U.reset();
      P.reset();
      arma_bad("lu(): failed to converge", false);
      }
    
    return status;
    }
  
  
  
  //! @}
  