view armadillo-2.4.4/include/armadillo_bits/fn_qr.hpp @ 32:28aafd0c1a5d slimline

Avoid crash on empty input

// Copyright (C) 2009-2012 NICTA (www.nicta.com.au)
// Copyright (C) 2009-2012 Conrad Sanderson
// 
// This file is part of the Armadillo C++ library.
// It is provided without any warranty of fitness
// for any purpose. You can redistribute this file
// and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published
// by the Free Software Foundation, either version 3
// of the License or (at your option) any later version.
// (see http://www.opensource.org/licenses for more info)


//! \addtogroup fn_qr
//! @{



//! QR decomposition
template<typename T1>
inline
bool
qr
  (
         Mat<typename T1::elem_type>&    Q,
         Mat<typename T1::elem_type>&    R,
  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( (&Q == &R), "qr(): Q and R are the same object");
  
  const bool status = auxlib::qr(Q, R, X);
  
  if(status == false)
    {
    Q.reset();
    R.reset();
    arma_bad("qr(): failed to converge", false);
    }
  
  return status;
  }



//! @}