Chris@49: // Copyright (C) 2009-2011 NICTA (www.nicta.com.au)
Chris@49: // Copyright (C) 2009-2011 Conrad Sanderson
Chris@49: // Copyright (C) 2009-2010 Dimitrios Bouzas
Chris@49: // Copyright (C) 2011 Stanislav Funiak
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_rank
Chris@49: //! @{
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1>
Chris@49: inline
Chris@49: arma_warn_unused
Chris@49: uword
Chris@49: rank
Chris@49:   (
Chris@49:   const Base<typename T1::elem_type,T1>& X,
Chris@49:         typename T1::pod_type            tol = 0.0,
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:   typedef typename T1::pod_type T;
Chris@49:   
Chris@49:   uword  X_n_rows;
Chris@49:   uword  X_n_cols;
Chris@49:   Col<T> s;
Chris@49:   
Chris@49:   const bool  status = auxlib::svd(s, X, X_n_rows, X_n_cols);
Chris@49:   const uword n_elem = s.n_elem;
Chris@49:   
Chris@49:   if(status == true)
Chris@49:     {
Chris@49:     if( (tol == T(0)) && (n_elem > 0) )
Chris@49:       {
Chris@49:       tol = (std::max)(X_n_rows, X_n_cols) * eop_aux::direct_eps(max(s));
Chris@49:       }
Chris@49:     
Chris@49:     // count non zero valued elements in s
Chris@49:     
Chris@49:     const T*  s_mem  = s.memptr();
Chris@49:           uword count  = 0;
Chris@49:     
Chris@49:     for(uword i=0; i<n_elem; ++i)
Chris@49:       {
Chris@49:       if(s_mem[i] > tol)
Chris@49:         {
Chris@49:         ++count;
Chris@49:         }
Chris@49:       }
Chris@49:     
Chris@49:     return count;
Chris@49:     }
Chris@49:   else
Chris@49:     {
Chris@49:     arma_bad("rank(): failed to converge");
Chris@49:     
Chris@49:     return uword(0);
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //! @}