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

Armadillo Library

+// Copyright (C) 2011-2012 NICTA (www.nicta.com.au)
+// Copyright (C) 2011-2012 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_syl_lyap
+//! @{
+
+
+//! find the solution of the Sylvester equation AX + XB = C
+template<typename T1, typename T2, typename T3>
+inline
+bool
+syl
+  (
+        Mat <typename T1::elem_type>   & out,
+  const Base<typename T1::elem_type,T1>& in_A,
+  const Base<typename T1::elem_type,T2>& in_B,
+  const Base<typename T1::elem_type,T3>& in_C,
+  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;
+  
+  const unwrap_check<T1> tmp_A(in_A.get_ref(), out);
+  const unwrap_check<T2> tmp_B(in_B.get_ref(), out);
+  const unwrap_check<T3> tmp_C(in_C.get_ref(), out);
+  
+  const Mat<eT>& A = tmp_A.M;
+  const Mat<eT>& B = tmp_B.M;
+  const Mat<eT>& C = tmp_C.M;
+  
+  const bool status = auxlib::syl(out, A, B, C);
+  
+  if(status == false)
+    {
+    out.reset();
+    arma_bad("syl(): equation appears to be singular", false);
+    }
+  
+  return status;
+  }
+
+
+
+template<typename T1, typename T2, typename T3>
+inline
+Mat<typename T1::elem_type>
+syl
+  (
+  const Base<typename T1::elem_type,T1>& in_A,
+  const Base<typename T1::elem_type,T2>& in_B,
+  const Base<typename T1::elem_type,T3>& in_C,
+  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;
+  
+  const unwrap<T1> tmp_A( in_A.get_ref() );
+  const unwrap<T2> tmp_B( in_B.get_ref() );
+  const unwrap<T3> tmp_C( in_C.get_ref() );
+  
+  const Mat<eT>& A = tmp_A.M;
+  const Mat<eT>& B = tmp_B.M;
+  const Mat<eT>& C = tmp_C.M;
+  
+  Mat<eT> out;
+  
+  const bool status = auxlib::syl(out, A, B, C);
+  
+  if(status == false)
+    {
+    out.reset();
+    arma_bad("syl(): equation appears to be singular");
+    }
+  
+  return out;
+  }
+
+
+
+//! @}