source: pacpussensors/trunk/Vislab/lib3dv/eigen/Eigen/src/SparseCore/TriangularSolver.h@ 136

Last change on this file since 136 was 136, checked in by ldecherf, 7 years ago

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1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
5//
6// This Source Code Form is subject to the terms of the Mozilla
7// Public License v. 2.0. If a copy of the MPL was not distributed
8// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9
10#ifndef EIGEN_SPARSETRIANGULARSOLVER_H
11#define EIGEN_SPARSETRIANGULARSOLVER_H
12
13namespace Eigen {
14
15namespace internal {
16
17template<typename Lhs, typename Rhs, int Mode,
18 int UpLo = (Mode & Lower)
19 ? Lower
20 : (Mode & Upper)
21 ? Upper
22 : -1,
23 int StorageOrder = int(traits<Lhs>::Flags) & RowMajorBit>
24struct sparse_solve_triangular_selector;
25
26// forward substitution, row-major
27template<typename Lhs, typename Rhs, int Mode>
28struct sparse_solve_triangular_selector<Lhs,Rhs,Mode,Lower,RowMajor>
29{
30 typedef typename Rhs::Scalar Scalar;
31 static void run(const Lhs& lhs, Rhs& other)
32 {
33 for(int col=0 ; col<other.cols() ; ++col)
34 {
35 for(int i=0; i<lhs.rows(); ++i)
36 {
37 Scalar tmp = other.coeff(i,col);
38 Scalar lastVal(0);
39 int lastIndex = 0;
40 for(typename Lhs::InnerIterator it(lhs, i); it; ++it)
41 {
42 lastVal = it.value();
43 lastIndex = it.index();
44 if(lastIndex==i)
45 break;
46 tmp -= lastVal * other.coeff(lastIndex,col);
47 }
48 if (Mode & UnitDiag)
49 other.coeffRef(i,col) = tmp;
50 else
51 {
52 eigen_assert(lastIndex==i);
53 other.coeffRef(i,col) = tmp/lastVal;
54 }
55 }
56 }
57 }
58};
59
60// backward substitution, row-major
61template<typename Lhs, typename Rhs, int Mode>
62struct sparse_solve_triangular_selector<Lhs,Rhs,Mode,Upper,RowMajor>
63{
64 typedef typename Rhs::Scalar Scalar;
65 static void run(const Lhs& lhs, Rhs& other)
66 {
67 for(int col=0 ; col<other.cols() ; ++col)
68 {
69 for(int i=lhs.rows()-1 ; i>=0 ; --i)
70 {
71 Scalar tmp = other.coeff(i,col);
72 Scalar l_ii(0);
73 typename Lhs::InnerIterator it(lhs, i);
74 while(it && it.index()<i)
75 ++it;
76 if(!(Mode & UnitDiag))
77 {
78 eigen_assert(it && it.index()==i);
79 l_ii = it.value();
80 ++it;
81 }
82 else if (it && it.index() == i)
83 ++it;
84 for(; it; ++it)
85 {
86 tmp -= it.value() * other.coeff(it.index(),col);
87 }
88
89 if (Mode & UnitDiag)
90 other.coeffRef(i,col) = tmp;
91 else
92 other.coeffRef(i,col) = tmp/l_ii;
93 }
94 }
95 }
96};
97
98// forward substitution, col-major
99template<typename Lhs, typename Rhs, int Mode>
100struct sparse_solve_triangular_selector<Lhs,Rhs,Mode,Lower,ColMajor>
101{
102 typedef typename Rhs::Scalar Scalar;
103 static void run(const Lhs& lhs, Rhs& other)
104 {
105 for(int col=0 ; col<other.cols() ; ++col)
106 {
107 for(int i=0; i<lhs.cols(); ++i)
108 {
109 Scalar& tmp = other.coeffRef(i,col);
110 if (tmp!=Scalar(0)) // optimization when other is actually sparse
111 {
112 typename Lhs::InnerIterator it(lhs, i);
113 while(it && it.index()<i)
114 ++it;
115 if(!(Mode & UnitDiag))
116 {
117 eigen_assert(it && it.index()==i);
118 tmp /= it.value();
119 }
120 if (it && it.index()==i)
121 ++it;
122 for(; it; ++it)
123 other.coeffRef(it.index(), col) -= tmp * it.value();
124 }
125 }
126 }
127 }
128};
129
130// backward substitution, col-major
131template<typename Lhs, typename Rhs, int Mode>
132struct sparse_solve_triangular_selector<Lhs,Rhs,Mode,Upper,ColMajor>
133{
134 typedef typename Rhs::Scalar Scalar;
135 static void run(const Lhs& lhs, Rhs& other)
136 {
137 for(int col=0 ; col<other.cols() ; ++col)
138 {
139 for(int i=lhs.cols()-1; i>=0; --i)
140 {
141 Scalar& tmp = other.coeffRef(i,col);
142 if (tmp!=Scalar(0)) // optimization when other is actually sparse
143 {
144 if(!(Mode & UnitDiag))
145 {
146 // TODO replace this by a binary search. make sure the binary search is safe for partially sorted elements
147 typename Lhs::ReverseInnerIterator it(lhs, i);
148 while(it && it.index()!=i)
149 --it;
150 eigen_assert(it && it.index()==i);
151 other.coeffRef(i,col) /= it.value();
152 }
153 typename Lhs::InnerIterator it(lhs, i);
154 for(; it && it.index()<i; ++it)
155 other.coeffRef(it.index(), col) -= tmp * it.value();
156 }
157 }
158 }
159 }
160};
161
162} // end namespace internal
163
164template<typename ExpressionType,int Mode>
165template<typename OtherDerived>
166void SparseTriangularView<ExpressionType,Mode>::solveInPlace(MatrixBase<OtherDerived>& other) const
167{
168 eigen_assert(m_matrix.cols() == m_matrix.rows() && m_matrix.cols() == other.rows());
169 eigen_assert((!(Mode & ZeroDiag)) && bool(Mode & (Upper|Lower)));
170
171 enum { copy = internal::traits<OtherDerived>::Flags & RowMajorBit };
172
173 typedef typename internal::conditional<copy,
174 typename internal::plain_matrix_type_column_major<OtherDerived>::type, OtherDerived&>::type OtherCopy;
175 OtherCopy otherCopy(other.derived());
176
177 internal::sparse_solve_triangular_selector<ExpressionType, typename internal::remove_reference<OtherCopy>::type, Mode>::run(m_matrix, otherCopy);
178
179 if (copy)
180 other = otherCopy;
181}
182
183template<typename ExpressionType,int Mode>
184template<typename OtherDerived>
185typename internal::plain_matrix_type_column_major<OtherDerived>::type
186SparseTriangularView<ExpressionType,Mode>::solve(const MatrixBase<OtherDerived>& other) const
187{
188 typename internal::plain_matrix_type_column_major<OtherDerived>::type res(other);
189 solveInPlace(res);
190 return res;
191}
192
193// pure sparse path
194
195namespace internal {
196
197template<typename Lhs, typename Rhs, int Mode,
198 int UpLo = (Mode & Lower)
199 ? Lower
200 : (Mode & Upper)
201 ? Upper
202 : -1,
203 int StorageOrder = int(Lhs::Flags) & (RowMajorBit)>
204struct sparse_solve_triangular_sparse_selector;
205
206// forward substitution, col-major
207template<typename Lhs, typename Rhs, int Mode, int UpLo>
208struct sparse_solve_triangular_sparse_selector<Lhs,Rhs,Mode,UpLo,ColMajor>
209{
210 typedef typename Rhs::Scalar Scalar;
211 typedef typename promote_index_type<typename traits<Lhs>::Index,
212 typename traits<Rhs>::Index>::type Index;
213 static void run(const Lhs& lhs, Rhs& other)
214 {
215 const bool IsLower = (UpLo==Lower);
216 AmbiVector<Scalar,Index> tempVector(other.rows()*2);
217 tempVector.setBounds(0,other.rows());
218
219 Rhs res(other.rows(), other.cols());
220 res.reserve(other.nonZeros());
221
222 for(int col=0 ; col<other.cols() ; ++col)
223 {
224 // FIXME estimate number of non zeros
225 tempVector.init(.99/*float(other.col(col).nonZeros())/float(other.rows())*/);
226 tempVector.setZero();
227 tempVector.restart();
228 for (typename Rhs::InnerIterator rhsIt(other, col); rhsIt; ++rhsIt)
229 {
230 tempVector.coeffRef(rhsIt.index()) = rhsIt.value();
231 }
232
233 for(int i=IsLower?0:lhs.cols()-1;
234 IsLower?i<lhs.cols():i>=0;
235 i+=IsLower?1:-1)
236 {
237 tempVector.restart();
238 Scalar& ci = tempVector.coeffRef(i);
239 if (ci!=Scalar(0))
240 {
241 // find
242 typename Lhs::InnerIterator it(lhs, i);
243 if(!(Mode & UnitDiag))
244 {
245 if (IsLower)
246 {
247 eigen_assert(it.index()==i);
248 ci /= it.value();
249 }
250 else
251 ci /= lhs.coeff(i,i);
252 }
253 tempVector.restart();
254 if (IsLower)
255 {
256 if (it.index()==i)
257 ++it;
258 for(; it; ++it)
259 tempVector.coeffRef(it.index()) -= ci * it.value();
260 }
261 else
262 {
263 for(; it && it.index()<i; ++it)
264 tempVector.coeffRef(it.index()) -= ci * it.value();
265 }
266 }
267 }
268
269
270 int count = 0;
271 // FIXME compute a reference value to filter zeros
272 for (typename AmbiVector<Scalar,Index>::Iterator it(tempVector/*,1e-12*/); it; ++it)
273 {
274 ++ count;
275// std::cerr << "fill " << it.index() << ", " << col << "\n";
276// std::cout << it.value() << " ";
277 // FIXME use insertBack
278 res.insert(it.index(), col) = it.value();
279 }
280// std::cout << "tempVector.nonZeros() == " << int(count) << " / " << (other.rows()) << "\n";
281 }
282 res.finalize();
283 other = res.markAsRValue();
284 }
285};
286
287} // end namespace internal
288
289template<typename ExpressionType,int Mode>
290template<typename OtherDerived>
291void SparseTriangularView<ExpressionType,Mode>::solveInPlace(SparseMatrixBase<OtherDerived>& other) const
292{
293 eigen_assert(m_matrix.cols() == m_matrix.rows() && m_matrix.cols() == other.rows());
294 eigen_assert( (!(Mode & ZeroDiag)) && bool(Mode & (Upper|Lower)));
295
296// enum { copy = internal::traits<OtherDerived>::Flags & RowMajorBit };
297
298// typedef typename internal::conditional<copy,
299// typename internal::plain_matrix_type_column_major<OtherDerived>::type, OtherDerived&>::type OtherCopy;
300// OtherCopy otherCopy(other.derived());
301
302 internal::sparse_solve_triangular_sparse_selector<ExpressionType, OtherDerived, Mode>::run(m_matrix, other.derived());
303
304// if (copy)
305// other = otherCopy;
306}
307
308#ifdef EIGEN2_SUPPORT
309
310// deprecated stuff:
311
312/** \deprecated */
313template<typename Derived>
314template<typename OtherDerived>
315void SparseMatrixBase<Derived>::solveTriangularInPlace(MatrixBase<OtherDerived>& other) const
316{
317 this->template triangular<Flags&(Upper|Lower)>().solveInPlace(other);
318}
319
320/** \deprecated */
321template<typename Derived>
322template<typename OtherDerived>
323typename internal::plain_matrix_type_column_major<OtherDerived>::type
324SparseMatrixBase<Derived>::solveTriangular(const MatrixBase<OtherDerived>& other) const
325{
326 typename internal::plain_matrix_type_column_major<OtherDerived>::type res(other);
327 derived().solveTriangularInPlace(res);
328 return res;
329}
330#endif // EIGEN2_SUPPORT
331
332} // end namespace Eigen
333
334#endif // EIGEN_SPARSETRIANGULARSOLVER_H
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