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				| /* -*- c++ -*- (enables emacs c++ mode) */ | |
| /*=========================================================================== | |
|   | |
|  Copyright (C) 2002-2012 Yves Renard | |
|   | |
|  This file is a part of GETFEM++ | |
|   | |
|  Getfem++  is  free software;  you  can  redistribute  it  and/or modify it | |
|  under  the  terms  of the  GNU  Lesser General Public License as published | |
|  by  the  Free Software Foundation;  either version 3 of the License,  or | |
|  (at your option) any later version along with the GCC Runtime Library | |
|  Exception either version 3.1 or (at your option) any later version. | |
|  This program  is  distributed  in  the  hope  that it will be useful,  but | |
|  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
|  or  FITNESS  FOR  A PARTICULAR PURPOSE.  See the GNU Lesser General Public | |
|  License and GCC Runtime Library Exception for more details. | |
|  You  should  have received a copy of the GNU Lesser General Public License | |
|  along  with  this program;  if not, write to the Free Software Foundation, | |
|  Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA. | |
|   | |
|  As a special exception, you  may use  this file  as it is a part of a free | |
|  software  library  without  restriction.  Specifically,  if   other  files | |
|  instantiate  templates  or  use macros or inline functions from this file, | |
|  or  you compile this  file  and  link  it  with other files  to produce an | |
|  executable, this file  does  not  by itself cause the resulting executable | |
|  to be covered  by the GNU Lesser General Public License.  This   exception | |
|  does not  however  invalidate  any  other  reasons why the executable file | |
|  might be covered by the GNU Lesser General Public License. | |
|   | |
| ===========================================================================*/ | |
| 
 | |
| // This file is a modified version of ilut.h from ITL. | |
| // See http://osl.iu.edu/research/itl/ | |
| // Following the corresponding Copyright notice. | |
| //=========================================================================== | |
| // | |
| // Copyright (c) 1998-2001, University of Notre Dame. All rights reserved. | |
| // Redistribution and use in source and binary forms, with or without | |
| // modification, are permitted provided that the following conditions are met: | |
| // | |
| //    * Redistributions of source code must retain the above copyright | |
| //      notice, this list of conditions and the following disclaimer. | |
| //    * Redistributions in binary form must reproduce the above copyright | |
| //      notice, this list of conditions and the following disclaimer in the | |
| //      documentation and/or other materials provided with the distribution. | |
| //    * Neither the name of the University of Notre Dame nor the | |
| //      names of its contributors may be used to endorse or promote products | |
| //      derived from this software without specific prior written permission. | |
| // | |
| // THIS SOFTWARE  IS  PROVIDED  BY  THE TRUSTEES  OF  INDIANA UNIVERSITY  AND | |
| // CONTRIBUTORS  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,  INCLUDING, | |
| // BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND  FITNESS | |
| // FOR  A PARTICULAR PURPOSE ARE DISCLAIMED. IN  NO  EVENT SHALL THE TRUSTEES | |
| // OF INDIANA UNIVERSITY AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| // INCIDENTAL, SPECIAL, EXEMPLARY,  OR CONSEQUENTIAL DAMAGES (INCLUDING,  BUT | |
| // NOT  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| // DATA,  OR PROFITS;  OR BUSINESS  INTERRUPTION)  HOWEVER  CAUSED AND ON ANY | |
| // THEORY  OF  LIABILITY,  WHETHER  IN  CONTRACT,  STRICT  LIABILITY, OR TORT | |
| // (INCLUDING  NEGLIGENCE  OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| // THIS  SOFTWARE,  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| // | |
| //=========================================================================== | |
|  | |
| #ifndef GMM_PRECOND_ILUT_H | |
| #define GMM_PRECOND_ILUT_H | |
|  | |
| /**@file gmm_precond_ilut.h | |
|    @author  Andrew Lumsdaine <lums@osl.iu.edu>, Lie-Quan Lee <llee@osl.iu.edu> | |
|    @date June 5, 2003. | |
|    @brief ILUT:  Incomplete LU with threshold and K fill-in Preconditioner. | |
| */ | |
| 
 | |
| /* | |
|   Performane comparing for SSOR, ILU and ILUT based on sherman 5 matrix  | |
|   in Harwell-Boeing collection on Sun Ultra 30 UPA/PCI (UltraSPARC-II 296MHz) | |
|   Preconditioner & Factorization time  &  Number of Iteration \\ \hline | |
|   SSOR        &   0.010577  & 41 \\ | |
|   ILU         &   0.019336  & 32 \\ | |
|   ILUT with 0 fill-in and threshold of 1.0e-6 & 0.343612 &  23 \\ | |
|   ILUT with 5 fill-in and threshold of 1.0e-6 & 0.343612 &  18 \\ \hline | |
| */ | |
| 
 | |
| #include "gmm_precond.h" | |
|  | |
| namespace gmm { | |
| 
 | |
|   template<typename T> struct elt_rsvector_value_less_ { | |
|     inline bool operator()(const elt_rsvector_<T>& a,  | |
| 			   const elt_rsvector_<T>& b) const | |
|     { return (gmm::abs(a.e) > gmm::abs(b.e)); } | |
|   }; | |
| 
 | |
|   /** Incomplete LU with threshold and K fill-in Preconditioner. | |
|  | |
|   The algorithm of ILUT(A, 0, 1.0e-6) is slower than ILU(A). If No | |
|   fill-in is arrowed, you can use ILU instead of ILUT. | |
|  | |
|   Notes: The idea under a concrete Preconditioner such as ilut is to | |
|   create a Preconditioner object to use in iterative methods. | |
|   */ | |
|   template <typename Matrix> | |
|   class ilut_precond  { | |
|   public : | |
|     typedef typename linalg_traits<Matrix>::value_type value_type; | |
|     typedef wsvector<value_type> _wsvector; | |
|     typedef rsvector<value_type> _rsvector; | |
|     typedef row_matrix<_rsvector> LU_Matrix; | |
| 
 | |
|     bool invert; | |
|     LU_Matrix L, U; | |
| 
 | |
|   protected: | |
|     size_type K; | |
|     double eps;     | |
| 
 | |
|     template<typename M> void do_ilut(const M&, row_major); | |
|     void do_ilut(const Matrix&, col_major); | |
| 
 | |
|   public: | |
|     void build_with(const Matrix& A, int k_ = -1, double eps_ = double(-1)) { | |
|       if (k_ >= 0) K = k_; | |
|       if (eps_ >= double(0)) eps = eps_; | |
|       invert = false; | |
|       gmm::resize(L, mat_nrows(A), mat_ncols(A)); | |
|       gmm::resize(U, mat_nrows(A), mat_ncols(A)); | |
|       do_ilut(A, typename principal_orientation_type<typename | |
| 	      linalg_traits<Matrix>::sub_orientation>::potype()); | |
|     } | |
|     ilut_precond(const Matrix& A, int k_, double eps_)  | |
|       : L(mat_nrows(A), mat_ncols(A)), U(mat_nrows(A), mat_ncols(A)), | |
| 	K(k_), eps(eps_) { build_with(A); } | |
|     ilut_precond(size_type k_, double eps_) :  K(k_), eps(eps_) {} | |
|     ilut_precond(void) { K = 10; eps = 1E-7; } | |
|     size_type memsize() const {  | |
|       return sizeof(*this) + (nnz(U)+nnz(L))*sizeof(value_type); | |
|     } | |
|   }; | |
| 
 | |
|   template<typename Matrix> template<typename M>  | |
|   void ilut_precond<Matrix>::do_ilut(const M& A, row_major) { | |
|     typedef value_type T; | |
|     typedef typename number_traits<T>::magnitude_type R; | |
|      | |
|     size_type n = mat_nrows(A); | |
|     if (n == 0) return; | |
|     std::vector<T> indiag(n); | |
|     _wsvector w(mat_ncols(A)); | |
|     _rsvector ww(mat_ncols(A)), wL(mat_ncols(A)), wU(mat_ncols(A)); | |
|     T tmp; | |
|     gmm::clear(U); gmm::clear(L); | |
|     R prec = default_tol(R());  | |
|     R max_pivot = gmm::abs(A(0,0)) * prec; | |
| 
 | |
|     for (size_type i = 0; i < n; ++i) { | |
|       gmm::copy(mat_const_row(A, i), w); | |
|       double norm_row = gmm::vect_norm2(w); | |
| 
 | |
|       typename _wsvector::iterator wkold = w.end(); | |
|       for (typename _wsvector::iterator wk = w.begin(); | |
| 	   wk != w.end() && wk->first < i; ) { | |
| 	size_type k = wk->first; | |
| 	tmp = (wk->second) * indiag[k]; | |
| 	if (gmm::abs(tmp) < eps * norm_row) w.erase(k); | |
| 	else { wk->second += tmp; gmm::add(scaled(mat_row(U, k), -tmp), w); } | |
| 	if (wkold == w.end()) wk = w.begin(); else { wk = wkold; ++wk; } | |
| 	if (wk != w.end() && wk->first == k) | |
| 	  { if (wkold == w.end()) wkold = w.begin(); else ++wkold; ++wk; } | |
|       } | |
|       tmp = w[i]; | |
| 
 | |
|       if (gmm::abs(tmp) <= max_pivot) { | |
| 	GMM_WARNING2("pivot " << i << " too small. try with ilutp ?"); | |
| 	w[i] = tmp = T(1); | |
|       } | |
| 
 | |
|       max_pivot = std::max(max_pivot, std::min(gmm::abs(tmp) * prec, R(1))); | |
|       indiag[i] = T(1) / tmp; | |
|       gmm::clean(w, eps * norm_row); | |
|       gmm::copy(w, ww); | |
|       std::sort(ww.begin(), ww.end(), elt_rsvector_value_less_<T>()); | |
|       typename _rsvector::const_iterator wit = ww.begin(), wite = ww.end(); | |
| 
 | |
|       size_type nnl = 0, nnu = 0;     | |
|       wL.base_resize(K); wU.base_resize(K+1); | |
|       typename _rsvector::iterator witL = wL.begin(), witU = wU.begin(); | |
|       for (; wit != wite; ++wit)  | |
| 	if (wit->c < i) { if (nnl < K) { *witL++ = *wit; ++nnl; } } | |
| 	else { if (nnu < K  || wit->c == i) { *witU++ = *wit; ++nnu; } } | |
|       wL.base_resize(nnl); wU.base_resize(nnu); | |
|       std::sort(wL.begin(), wL.end()); | |
|       std::sort(wU.begin(), wU.end()); | |
|       gmm::copy(wL, L.row(i)); | |
|       gmm::copy(wU, U.row(i)); | |
|     } | |
| 
 | |
|   } | |
| 
 | |
|   template<typename Matrix>  | |
|   void ilut_precond<Matrix>::do_ilut(const Matrix& A, col_major) { | |
|     do_ilut(gmm::transposed(A), row_major()); | |
|     invert = true; | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void mult(const ilut_precond<Matrix>& P, const V1 &v1, V2 &v2) { | |
|     gmm::copy(v1, v2); | |
|     if (P.invert) { | |
|       gmm::lower_tri_solve(gmm::transposed(P.U), v2, false); | |
|       gmm::upper_tri_solve(gmm::transposed(P.L), v2, true); | |
|     } | |
|     else { | |
|       gmm::lower_tri_solve(P.L, v2, true); | |
|       gmm::upper_tri_solve(P.U, v2, false); | |
|     } | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void transposed_mult(const ilut_precond<Matrix>& P,const V1 &v1,V2 &v2) { | |
|     gmm::copy(v1, v2); | |
|     if (P.invert) { | |
|       gmm::lower_tri_solve(P.L, v2, true); | |
|       gmm::upper_tri_solve(P.U, v2, false); | |
|     } | |
|     else { | |
|       gmm::lower_tri_solve(gmm::transposed(P.U), v2, false); | |
|       gmm::upper_tri_solve(gmm::transposed(P.L), v2, true); | |
|     } | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void left_mult(const ilut_precond<Matrix>& P, const V1 &v1, V2 &v2) { | |
|     copy(v1, v2); | |
|     if (P.invert) gmm::lower_tri_solve(gmm::transposed(P.U), v2, false); | |
|     else gmm::lower_tri_solve(P.L, v2, true); | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void right_mult(const ilut_precond<Matrix>& P, const V1 &v1, V2 &v2) { | |
|     copy(v1, v2); | |
|     if (P.invert) gmm::upper_tri_solve(gmm::transposed(P.L), v2, true); | |
|     else gmm::upper_tri_solve(P.U, v2, false); | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void transposed_left_mult(const ilut_precond<Matrix>& P, const V1 &v1, | |
| 			    V2 &v2) { | |
|     copy(v1, v2); | |
|     if (P.invert) gmm::upper_tri_solve(P.U, v2, false); | |
|     else gmm::upper_tri_solve(gmm::transposed(P.L), v2, true); | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void transposed_right_mult(const ilut_precond<Matrix>& P, const V1 &v1, | |
| 			     V2 &v2) { | |
|     copy(v1, v2); | |
|     if (P.invert) gmm::lower_tri_solve(P.L, v2, true); | |
|     else gmm::lower_tri_solve(gmm::transposed(P.U), v2, false); | |
|   } | |
| 
 | |
| } | |
| 
 | |
| #endif  | |
| 
 |