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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 ilu.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. | |
| // | |
| //=========================================================================== | |
|  | |
| /**@file gmm_precond_ilu.h | |
|    @author Andrew Lumsdaine <lums@osl.iu.edu> | |
|    @author Lie-Quan Lee <llee@osl.iu.edu> | |
|    @author Yves Renard <yves.renard@insa-lyon.fr> | |
|    @date June 5, 2003. | |
|    @brief Incomplete LU without fill-in Preconditioner. | |
| */ | |
| 
 | |
| #ifndef GMM_PRECOND_ILU_H | |
| #define GMM_PRECOND_ILU_H | |
|  | |
| // | |
| // Notes: The idea under a concrete Preconditioner such  | |
| //        as Incomplete LU is to create a Preconditioner | |
| //        object to use in iterative methods.  | |
| // | |
|  | |
| #include "gmm_precond.h" | |
|  | |
| namespace gmm { | |
|   /** Incomplete LU without fill-in Preconditioner. */ | |
|   template <typename Matrix> | |
|   class ilu_precond { | |
| 
 | |
|   public : | |
|     typedef typename linalg_traits<Matrix>::value_type value_type; | |
|     typedef csr_matrix_ref<value_type *, size_type *, size_type *, 0> tm_type; | |
| 
 | |
|     tm_type U, L; | |
|     bool invert; | |
|   protected : | |
|     std::vector<value_type> L_val, U_val; | |
|     std::vector<size_type> L_ind, U_ind, L_ptr, U_ptr; | |
|   | |
|     template<typename M> void do_ilu(const M& A, row_major); | |
|     void do_ilu(const Matrix& A, col_major); | |
| 
 | |
|   public: | |
|      | |
|     size_type nrows(void) const { return mat_nrows(L); } | |
|     size_type ncols(void) const { return mat_ncols(U); } | |
|      | |
|     void build_with(const Matrix& A) { | |
|       invert = false; | |
|        L_ptr.resize(mat_nrows(A)+1); | |
|        U_ptr.resize(mat_nrows(A)+1); | |
|        do_ilu(A, typename principal_orientation_type<typename | |
| 	      linalg_traits<Matrix>::sub_orientation>::potype()); | |
|     } | |
|     ilu_precond(const Matrix& A) { build_with(A); } | |
|     ilu_precond(void) {} | |
|     size_type memsize() const {  | |
|       return sizeof(*this) +  | |
| 	(L_val.size()+U_val.size()) * sizeof(value_type) +  | |
| 	(L_ind.size()+L_ptr.size()) * sizeof(size_type) + | |
| 	(U_ind.size()+U_ptr.size()) * sizeof(size_type);  | |
|     } | |
|   }; | |
| 
 | |
|   template <typename Matrix> template <typename M> | |
|   void ilu_precond<Matrix>::do_ilu(const M& A, row_major) { | |
|     typedef typename linalg_traits<Matrix>::storage_type store_type; | |
|     typedef value_type T; | |
|     typedef typename number_traits<T>::magnitude_type R; | |
| 
 | |
|     size_type L_loc = 0, U_loc = 0, n = mat_nrows(A), i, j, k; | |
|     if (n == 0) return; | |
|     L_ptr[0] = 0; U_ptr[0] = 0; | |
|     R prec = default_tol(R()); | |
|     R max_pivot = gmm::abs(A(0,0)) * prec; | |
| 
 | |
| 
 | |
|     for (int count = 0; count < 2; ++count) { | |
|       if (count) {  | |
| 	L_val.resize(L_loc); L_ind.resize(L_loc); | |
| 	U_val.resize(U_loc); U_ind.resize(U_loc); | |
|       } | |
|       L_loc = U_loc = 0; | |
|       for (i = 0; i < n; ++i) { | |
| 	typedef typename linalg_traits<M>::const_sub_row_type row_type; | |
| 	row_type row = mat_const_row(A, i); | |
| 	typename linalg_traits<row_type>::const_iterator | |
| 	  it = vect_const_begin(row), ite = vect_const_end(row); | |
| 	 | |
| 	if (count) { U_val[U_loc] = T(0); U_ind[U_loc] = i; } | |
| 	++U_loc; // diagonal element | |
| 	 | |
| 	for (k = 0; it != ite && k < 1000; ++it, ++k) { | |
| 	  // if a plain row is present, retains only the 1000 firsts | |
| 	  // nonzero elements. ---> a sort should be done. | |
| 	  j = index_of_it(it, k, store_type()); | |
| 	  if (j < i) { | |
| 	    if (count) { L_val[L_loc] = *it; L_ind[L_loc] = j; } | |
| 	    L_loc++; | |
| 	  } | |
| 	  else if (i == j) { | |
| 	    if (count) U_val[U_loc-1] = *it; | |
| 	  } | |
| 	  else { | |
| 	    if (count) { U_val[U_loc] = *it; U_ind[U_loc] = j; } | |
| 	    U_loc++; | |
| 	  } | |
| 	} | |
|         L_ptr[i+1] = L_loc; U_ptr[i+1] = U_loc; | |
|       } | |
|     } | |
|      | |
|     if (A(0,0) == T(0)) { | |
|       U_val[U_ptr[0]] = T(1); | |
|       GMM_WARNING2("pivot 0 is too small"); | |
|     } | |
| 
 | |
|     size_type qn, pn, rn; | |
|     for (i = 1; i < n; i++) { | |
| 
 | |
|       pn = U_ptr[i]; | |
|       if (gmm::abs(U_val[pn]) <= max_pivot) { | |
| 	U_val[pn] = T(1); | |
| 	GMM_WARNING2("pivot " << i << " is too small"); | |
|       } | |
|       max_pivot = std::max(max_pivot, | |
| 			   std::min(gmm::abs(U_val[pn]) * prec, R(1))); | |
| 
 | |
|       for (j = L_ptr[i]; j < L_ptr[i+1]; j++) { | |
| 	pn = U_ptr[L_ind[j]]; | |
| 	 | |
| 	T multiplier = (L_val[j] /= U_val[pn]); | |
| 	 | |
| 	qn = j + 1; | |
| 	rn = U_ptr[i]; | |
| 	 | |
| 	for (pn++; pn < U_ptr[L_ind[j]+1] && U_ind[pn] < i; pn++) { | |
| 	  while (qn < L_ptr[i+1] && L_ind[qn] < U_ind[pn]) | |
| 	    qn++; | |
| 	  if (qn < L_ptr[i+1] && U_ind[pn] == L_ind[qn]) | |
| 	    L_val[qn] -= multiplier * U_val[pn]; | |
| 	} | |
| 	for (; pn < U_ptr[L_ind[j]+1]; pn++) { | |
| 	  while (rn < U_ptr[i+1] && U_ind[rn] < U_ind[pn]) | |
| 	    rn++; | |
| 	  if (rn < U_ptr[i+1] && U_ind[pn] == U_ind[rn]) | |
| 	    U_val[rn] -= multiplier * U_val[pn]; | |
| 	} | |
|       } | |
|     } | |
| 
 | |
|     L = tm_type(&(L_val[0]), &(L_ind[0]), &(L_ptr[0]), n, mat_ncols(A)); | |
|     U = tm_type(&(U_val[0]), &(U_ind[0]), &(U_ptr[0]), n, mat_ncols(A)); | |
|   } | |
|    | |
|   template <typename Matrix> | |
|   void ilu_precond<Matrix>::do_ilu(const Matrix& A, col_major) { | |
|     do_ilu(gmm::transposed(A), row_major()); | |
|     invert = true; | |
|   } | |
| 
 | |
|   template <typename Matrix, typename V1, typename V2> inline | |
|   void mult(const ilu_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 ilu_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 ilu_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 ilu_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 ilu_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 ilu_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  | |
| 
 |