TBCI Numerical high perf. C++ Library: ir.h Source File

00001 
00004 // $Id: ir.h,v 1.7.2.2 2003/07/13 22:25:07 garloff Exp $
00005 
00006 #ifndef TBCI_SOLVER_IR_H
00007 #define TBCI_SOLVER_IR_H
00008 
00009 #include "../basics.h"
00010 
00011 NAMESPACE_TBCI
00012 
00031 INST3(template <typename T, Matrix<T>, Vector<T> > class NN friend \
00032 int IR (const Matrix<T>&, Vector<T>&, const Vector<T>&,\
00033         const Preconditioner_Sig<T, Matrix<T> >&, unsigned int&, double&);)
00034 INST3(template <typename T, BdMatrix<T>, Vector<T> > class NN friend \
00035 int IR (const BdMatrix<T>&, Vector<T>&, const Vector<T>&,\
00036         const Preconditioner_Sig<T, BdMatrix<T> >&, unsigned int&, double&);)
00037 
00038 
00039 //Aenderung Marco:
00040 template < typename T, typename SysMatrix, typename SysVector >
00041 int IR (const SysMatrix &A, SysVector &x, const SysVector &b,
00042         const Preconditioner_Sig<T, SysMatrix> &M, unsigned int &max_iter, double &tol)
00043 {
00044   double resid;
00045   unsigned int dim = A.rows();
00046   SysVector z(dim);
00047 
00048   double normb = b.fabs();
00049   if (normb == 0.0)  normb = 1.0;
00050   SysVector r(b - A*x);
00051 
00052   
00053   if ((resid = r.fabs() / normb) <= tol) 
00054   {
00055     tol = resid;
00056     max_iter = 0;
00057     return 0;
00058   }
00059   
00060   for (unsigned int i = 1; i <= max_iter; i++) 
00061   {
00062     z = M.solve(r);
00063     x += z;
00064     r = b - A * x;
00065     if ((resid = r.fabs() / normb) <= tol) 
00066     {
00067       tol = resid;
00068       max_iter = i;
00069       return 0;
00070     }
00071   }
00072 
00073   tol = resid;
00074   return 1;
00075 }
00076 
00077 NAMESPACE_END
00078 
00079 #endif