comparison armadillo-2.4.4/include/armadillo_bits/fn_rank.hpp @ 0:8b6102e2a9b0

Armadillo Library

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