1 files changed, 174 insertions, 0 deletions
diff --git a/src/armadillo/include/armadillo_bits/op_cond_meat.hpp b/src/armadillo/include/armadillo_bits/op_cond_meat.hpp
new file mode 100644
index 0000000..f73ef9a
--- /dev/null
+++ b/src/armadillo/include/armadillo_bits/op_cond_meat.hpp
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: Apache-2.0
+// 
+// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
+// Copyright 2008-2016 National ICT Australia (NICTA)
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ------------------------------------------------------------------------
+
+
+//! \addtogroup op_cond
+//! @{
+
+
+
+template<typename T1>
+inline
+typename T1::pod_type
+op_cond::apply(const Base<typename T1::elem_type, T1>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  typedef typename T1::pod_type   T;
+  
+  Mat<eT> A(X.get_ref());
+  
+  if(A.n_elem == 0)  { return T(0); }
+  
+  if(is_op_diagmat<T1>::value || A.is_diagmat())
+    {
+    arma_extra_debug_print("op_cond::apply(): detected diagonal matrix");
+    
+    return op_cond::apply_diag(A);
+    }
+  
+  bool is_approx_sym   = false;
+  bool is_approx_sympd = false;
+  
+  sym_helper::analyse_matrix(is_approx_sym, is_approx_sympd, A);
+  
+  const bool do_sym = (is_cx<eT>::no) ? (is_approx_sym) : (is_approx_sym && is_approx_sympd);
+  
+  if(do_sym)
+    {
+    arma_extra_debug_print("op_cond: symmetric/hermitian optimisation");
+    
+    return op_cond::apply_sym(A);
+    }
+  
+  return op_cond::apply_gen(A);
+  }
+
+
+
+template<typename eT>
+inline
+typename get_pod_type<eT>::result
+op_cond::apply_diag(const Mat<eT>& A)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename get_pod_type<eT>::result T;
+  
+  const uword N = (std::min)(A.n_rows, A.n_cols);
+  
+  T abs_min = Datum<T>::inf;
+  T abs_max = T(0);
+  
+  for(uword i=0; i < N; ++i)
+    {
+    const T abs_val = std::abs(A.at(i,i));
+    
+    if(arma_isnan(abs_val))
+      {
+      arma_debug_warn_level(3, "cond(): failed");
+      
+      return Datum<T>::nan;
+      }
+    
+    abs_min = (abs_val < abs_min) ? abs_val : abs_min;
+    abs_max = (abs_val > abs_max) ? abs_val : abs_max;
+    }
+  
+  if((abs_min == T(0)) || (abs_max == T(0)))  { return Datum<T>::inf; }
+  
+  return T(abs_max / abs_min);
+  }
+
+
+
+template<typename eT>
+inline
+typename get_pod_type<eT>::result
+op_cond::apply_sym(Mat<eT>& A)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename get_pod_type<eT>::result T;
+  
+  Col<T> eigval;
+  
+  const bool status = auxlib::eig_sym(eigval, A);
+  
+  if(status == false)
+    {
+    arma_debug_warn_level(3, "cond(): failed");
+    
+    return Datum<T>::nan;
+    }
+  
+  if(eigval.n_elem == 0)  { return T(0); }
+  
+  const T* eigval_mem = eigval.memptr();
+  
+  T abs_min = std::abs(eigval_mem[0]);
+  T abs_max = abs_min;
+  
+  for(uword i=1; i < eigval.n_elem; ++i)
+    {
+    const T abs_val = std::abs(eigval_mem[i]);
+    
+    abs_min = (abs_val < abs_min) ? abs_val : abs_min;
+    abs_max = (abs_val > abs_max) ? abs_val : abs_max;
+    }
+  
+  if((abs_min == T(0)) || (abs_max == T(0)))  { return Datum<T>::inf; }
+  
+  return T(abs_max / abs_min);
+  }
+
+
+
+template<typename eT>
+inline
+typename get_pod_type<eT>::result
+op_cond::apply_gen(Mat<eT>& A)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename get_pod_type<eT>::result T;
+  
+  Col<T> S;
+  
+  const bool status = auxlib::svd_dc(S, A);
+  
+  if(status == false)
+    {
+    arma_debug_warn_level(3, "cond(): failed");
+    
+    return Datum<T>::nan;
+    }
+  
+  if(S.n_elem == 0)  { return T(0); }
+  
+  const T S_max = S[0];
+  const T S_min = S[S.n_elem-1];
+  
+  if((S_max == T(0)) || (S_min == T(0)))  { return Datum<T>::inf; }
+  
+  return T(S_max / S_min);
+  }
+
+
+
+//! @}