1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2008-2009 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_SPARSE_BLOCK_H
11 #define EIGEN_SPARSE_BLOCK_H
12 
13 namespace Eigen {
14 
15 template<typename XprType, int BlockRows, int BlockCols>
16 class BlockImpl<XprType,BlockRows,BlockCols,true,Sparse>
17   : public SparseMatrixBase<Block<XprType,BlockRows,BlockCols,true> >
18 {
19     typedef typename internal::remove_all<typename XprType::Nested>::type _MatrixTypeNested;
20     typedef Block<XprType, BlockRows, BlockCols, true> BlockType;
21 public:
22     enum { IsRowMajor = internal::traits<BlockType>::IsRowMajor };
23 protected:
24     enum { OuterSize = IsRowMajor ? BlockRows : BlockCols };
25 public:
EIGEN_SPARSE_PUBLIC_INTERFACE(BlockType)26     EIGEN_SPARSE_PUBLIC_INTERFACE(BlockType)
27 
28     class InnerIterator: public XprType::InnerIterator
29     {
30         typedef typename BlockImpl::Index Index;
31       public:
32         inline InnerIterator(const BlockType& xpr, Index outer)
33           : XprType::InnerIterator(xpr.m_matrix, xpr.m_outerStart + outer), m_outer(outer)
34         {}
35         inline Index row() const { return IsRowMajor ? m_outer : this->index(); }
36         inline Index col() const { return IsRowMajor ? this->index() : m_outer; }
37       protected:
38         Index m_outer;
39     };
40     class ReverseInnerIterator: public XprType::ReverseInnerIterator
41     {
42         typedef typename BlockImpl::Index Index;
43       public:
ReverseInnerIterator(const BlockType & xpr,Index outer)44         inline ReverseInnerIterator(const BlockType& xpr, Index outer)
45           : XprType::ReverseInnerIterator(xpr.m_matrix, xpr.m_outerStart + outer), m_outer(outer)
46         {}
row()47         inline Index row() const { return IsRowMajor ? m_outer : this->index(); }
col()48         inline Index col() const { return IsRowMajor ? this->index() : m_outer; }
49       protected:
50         Index m_outer;
51     };
52 
BlockImpl(const XprType & xpr,int i)53     inline BlockImpl(const XprType& xpr, int i)
54       : m_matrix(xpr), m_outerStart(i), m_outerSize(OuterSize)
55     {}
56 
BlockImpl(const XprType & xpr,int startRow,int startCol,int blockRows,int blockCols)57     inline BlockImpl(const XprType& xpr, int startRow, int startCol, int blockRows, int blockCols)
58       : m_matrix(xpr), m_outerStart(IsRowMajor ? startRow : startCol), m_outerSize(IsRowMajor ? blockRows : blockCols)
59     {}
60 
rows()61     EIGEN_STRONG_INLINE Index rows() const { return IsRowMajor ? m_outerSize.value() : m_matrix.rows(); }
cols()62     EIGEN_STRONG_INLINE Index cols() const { return IsRowMajor ? m_matrix.cols() : m_outerSize.value(); }
63 
64   protected:
65 
66     typename XprType::Nested m_matrix;
67     Index m_outerStart;
68     const internal::variable_if_dynamic<Index, OuterSize> m_outerSize;
69 
70     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl)
71   private:
72     Index nonZeros() const;
73 };
74 
75 
76 /***************************************************************************
77 * specialisation for SparseMatrix
78 ***************************************************************************/
79 
80 template<typename _Scalar, int _Options, typename _Index, int BlockRows, int BlockCols>
81 class BlockImpl<SparseMatrix<_Scalar, _Options, _Index>,BlockRows,BlockCols,true,Sparse>
82   : public SparseMatrixBase<Block<SparseMatrix<_Scalar, _Options, _Index>,BlockRows,BlockCols,true> >
83 {
84     typedef SparseMatrix<_Scalar, _Options, _Index> SparseMatrixType;
85     typedef typename internal::remove_all<typename SparseMatrixType::Nested>::type _MatrixTypeNested;
86     typedef Block<SparseMatrixType, BlockRows, BlockCols, true> BlockType;
87     typedef Block<const SparseMatrixType, BlockRows, BlockCols, true> ConstBlockType;
88 public:
89     enum { IsRowMajor = internal::traits<BlockType>::IsRowMajor };
90     EIGEN_SPARSE_PUBLIC_INTERFACE(BlockType)
91 protected:
92     enum { OuterSize = IsRowMajor ? BlockRows : BlockCols };
93 public:
94 
95     class InnerIterator: public SparseMatrixType::InnerIterator
96     {
97       public:
InnerIterator(const BlockType & xpr,Index outer)98         inline InnerIterator(const BlockType& xpr, Index outer)
99           : SparseMatrixType::InnerIterator(xpr.m_matrix, xpr.m_outerStart + outer), m_outer(outer)
100         {}
row()101         inline Index row() const { return IsRowMajor ? m_outer : this->index(); }
col()102         inline Index col() const { return IsRowMajor ? this->index() : m_outer; }
103       protected:
104         Index m_outer;
105     };
106     class ReverseInnerIterator: public SparseMatrixType::ReverseInnerIterator
107     {
108       public:
ReverseInnerIterator(const BlockType & xpr,Index outer)109         inline ReverseInnerIterator(const BlockType& xpr, Index outer)
110           : SparseMatrixType::ReverseInnerIterator(xpr.m_matrix, xpr.m_outerStart + outer), m_outer(outer)
111         {}
row()112         inline Index row() const { return IsRowMajor ? m_outer : this->index(); }
col()113         inline Index col() const { return IsRowMajor ? this->index() : m_outer; }
114       protected:
115         Index m_outer;
116     };
117 
BlockImpl(const SparseMatrixType & xpr,int i)118     inline BlockImpl(const SparseMatrixType& xpr, int i)
119       : m_matrix(xpr), m_outerStart(i), m_outerSize(OuterSize)
120     {}
121 
BlockImpl(const SparseMatrixType & xpr,int startRow,int startCol,int blockRows,int blockCols)122     inline BlockImpl(const SparseMatrixType& xpr, int startRow, int startCol, int blockRows, int blockCols)
123       : m_matrix(xpr), m_outerStart(IsRowMajor ? startRow : startCol), m_outerSize(IsRowMajor ? blockRows : blockCols)
124     {}
125 
126     template<typename OtherDerived>
127     inline BlockType& operator=(const SparseMatrixBase<OtherDerived>& other)
128     {
129       typedef typename internal::remove_all<typename SparseMatrixType::Nested>::type _NestedMatrixType;
130       _NestedMatrixType& matrix = const_cast<_NestedMatrixType&>(m_matrix);;
131       // This assignement is slow if this vector set is not empty
132       // and/or it is not at the end of the nonzeros of the underlying matrix.
133 
134       // 1 - eval to a temporary to avoid transposition and/or aliasing issues
135       SparseMatrix<Scalar, IsRowMajor ? RowMajor : ColMajor, Index> tmp(other);
136 
137       // 2 - let's check whether there is enough allocated memory
138       Index nnz           = tmp.nonZeros();
139       Index start         = m_outerStart==0 ? 0 : matrix.outerIndexPtr()[m_outerStart]; // starting position of the current block
140       Index end           = m_matrix.outerIndexPtr()[m_outerStart+m_outerSize.value()]; // ending posiiton of the current block
141       Index block_size    = end - start;                                                // available room in the current block
142       Index tail_size     = m_matrix.outerIndexPtr()[m_matrix.outerSize()] - end;
143 
144       Index free_size     = m_matrix.isCompressed()
145                           ? Index(matrix.data().allocatedSize()) + block_size
146                           : block_size;
147 
148       if(nnz>free_size)
149       {
150         // realloc manually to reduce copies
151         typename SparseMatrixType::Storage newdata(m_matrix.data().allocatedSize() - block_size + nnz);
152 
153         std::memcpy(&newdata.value(0), &m_matrix.data().value(0), start*sizeof(Scalar));
154         std::memcpy(&newdata.index(0), &m_matrix.data().index(0), start*sizeof(Index));
155 
156         std::memcpy(&newdata.value(start), &tmp.data().value(0), nnz*sizeof(Scalar));
157         std::memcpy(&newdata.index(start), &tmp.data().index(0), nnz*sizeof(Index));
158 
159         std::memcpy(&newdata.value(start+nnz), &matrix.data().value(end), tail_size*sizeof(Scalar));
160         std::memcpy(&newdata.index(start+nnz), &matrix.data().index(end), tail_size*sizeof(Index));
161 
162         newdata.resize(m_matrix.outerIndexPtr()[m_matrix.outerSize()] - block_size + nnz);
163 
164         matrix.data().swap(newdata);
165       }
166       else
167       {
168         // no need to realloc, simply copy the tail at its respective position and insert tmp
169         matrix.data().resize(start + nnz + tail_size);
170 
171         std::memmove(&matrix.data().value(start+nnz), &matrix.data().value(end), tail_size*sizeof(Scalar));
172         std::memmove(&matrix.data().index(start+nnz), &matrix.data().index(end), tail_size*sizeof(Index));
173 
174         std::memcpy(&matrix.data().value(start), &tmp.data().value(0), nnz*sizeof(Scalar));
175         std::memcpy(&matrix.data().index(start), &tmp.data().index(0), nnz*sizeof(Index));
176       }
177 
178       // update innerNonZeros
179       if(!m_matrix.isCompressed())
180         for(Index j=0; j<m_outerSize.value(); ++j)
181           matrix.innerNonZeroPtr()[m_outerStart+j] = tmp.innerVector(j).nonZeros();
182 
183       // update outer index pointers
184       Index p = start;
185       for(Index k=0; k<m_outerSize.value(); ++k)
186       {
187         matrix.outerIndexPtr()[m_outerStart+k] = p;
188         p += tmp.innerVector(k).nonZeros();
189       }
190       std::ptrdiff_t offset = nnz - block_size;
191       for(Index k = m_outerStart + m_outerSize.value(); k<=matrix.outerSize(); ++k)
192       {
193         matrix.outerIndexPtr()[k] += offset;
194       }
195 
196       return derived();
197     }
198 
199     inline BlockType& operator=(const BlockType& other)
200     {
201       return operator=<BlockType>(other);
202     }
203 
valuePtr()204     inline const Scalar* valuePtr() const
205     { return m_matrix.valuePtr() + m_matrix.outerIndexPtr()[m_outerStart]; }
valuePtr()206     inline Scalar* valuePtr()
207     { return m_matrix.const_cast_derived().valuePtr() + m_matrix.outerIndexPtr()[m_outerStart]; }
208 
innerIndexPtr()209     inline const Index* innerIndexPtr() const
210     { return m_matrix.innerIndexPtr() + m_matrix.outerIndexPtr()[m_outerStart]; }
innerIndexPtr()211     inline Index* innerIndexPtr()
212     { return m_matrix.const_cast_derived().innerIndexPtr() + m_matrix.outerIndexPtr()[m_outerStart]; }
213 
outerIndexPtr()214     inline const Index* outerIndexPtr() const
215     { return m_matrix.outerIndexPtr() + m_outerStart; }
outerIndexPtr()216     inline Index* outerIndexPtr()
217     { return m_matrix.const_cast_derived().outerIndexPtr() + m_outerStart; }
218 
nonZeros()219     Index nonZeros() const
220     {
221       if(m_matrix.isCompressed())
222         return  std::size_t(m_matrix.outerIndexPtr()[m_outerStart+m_outerSize.value()])
223               - std::size_t(m_matrix.outerIndexPtr()[m_outerStart]);
224       else if(m_outerSize.value()==0)
225         return 0;
226       else
227         return Map<const Matrix<Index,OuterSize,1> >(m_matrix.innerNonZeroPtr()+m_outerStart, m_outerSize.value()).sum();
228     }
229 
lastCoeff()230     const Scalar& lastCoeff() const
231     {
232       EIGEN_STATIC_ASSERT_VECTOR_ONLY(BlockImpl);
233       eigen_assert(nonZeros()>0);
234       if(m_matrix.isCompressed())
235         return m_matrix.valuePtr()[m_matrix.outerIndexPtr()[m_outerStart+1]-1];
236       else
237         return m_matrix.valuePtr()[m_matrix.outerIndexPtr()[m_outerStart]+m_matrix.innerNonZeroPtr()[m_outerStart]-1];
238     }
239 
rows()240     EIGEN_STRONG_INLINE Index rows() const { return IsRowMajor ? m_outerSize.value() : m_matrix.rows(); }
cols()241     EIGEN_STRONG_INLINE Index cols() const { return IsRowMajor ? m_matrix.cols() : m_outerSize.value(); }
242 
243   protected:
244 
245     typename SparseMatrixType::Nested m_matrix;
246     Index m_outerStart;
247     const internal::variable_if_dynamic<Index, OuterSize> m_outerSize;
248 
249 };
250 
251 
252 template<typename _Scalar, int _Options, typename _Index, int BlockRows, int BlockCols>
253 class BlockImpl<const SparseMatrix<_Scalar, _Options, _Index>,BlockRows,BlockCols,true,Sparse>
254   : public SparseMatrixBase<Block<const SparseMatrix<_Scalar, _Options, _Index>,BlockRows,BlockCols,true> >
255 {
256     typedef SparseMatrix<_Scalar, _Options, _Index> SparseMatrixType;
257     typedef typename internal::remove_all<typename SparseMatrixType::Nested>::type _MatrixTypeNested;
258     typedef Block<const SparseMatrixType, BlockRows, BlockCols, true> BlockType;
259 public:
260     enum { IsRowMajor = internal::traits<BlockType>::IsRowMajor };
261     EIGEN_SPARSE_PUBLIC_INTERFACE(BlockType)
262 protected:
263     enum { OuterSize = IsRowMajor ? BlockRows : BlockCols };
264 public:
265 
266     class InnerIterator: public SparseMatrixType::InnerIterator
267     {
268       public:
InnerIterator(const BlockType & xpr,Index outer)269         inline InnerIterator(const BlockType& xpr, Index outer)
270           : SparseMatrixType::InnerIterator(xpr.m_matrix, xpr.m_outerStart + outer), m_outer(outer)
271         {}
row()272         inline Index row() const { return IsRowMajor ? m_outer : this->index(); }
col()273         inline Index col() const { return IsRowMajor ? this->index() : m_outer; }
274       protected:
275         Index m_outer;
276     };
277     class ReverseInnerIterator: public SparseMatrixType::ReverseInnerIterator
278     {
279       public:
ReverseInnerIterator(const BlockType & xpr,Index outer)280         inline ReverseInnerIterator(const BlockType& xpr, Index outer)
281           : SparseMatrixType::ReverseInnerIterator(xpr.m_matrix, xpr.m_outerStart + outer), m_outer(outer)
282         {}
row()283         inline Index row() const { return IsRowMajor ? m_outer : this->index(); }
col()284         inline Index col() const { return IsRowMajor ? this->index() : m_outer; }
285       protected:
286         Index m_outer;
287     };
288 
BlockImpl(const SparseMatrixType & xpr,int i)289     inline BlockImpl(const SparseMatrixType& xpr, int i)
290       : m_matrix(xpr), m_outerStart(i), m_outerSize(OuterSize)
291     {}
292 
BlockImpl(const SparseMatrixType & xpr,int startRow,int startCol,int blockRows,int blockCols)293     inline BlockImpl(const SparseMatrixType& xpr, int startRow, int startCol, int blockRows, int blockCols)
294       : m_matrix(xpr), m_outerStart(IsRowMajor ? startRow : startCol), m_outerSize(IsRowMajor ? blockRows : blockCols)
295     {}
296 
valuePtr()297     inline const Scalar* valuePtr() const
298     { return m_matrix.valuePtr() + m_matrix.outerIndexPtr()[m_outerStart]; }
299 
innerIndexPtr()300     inline const Index* innerIndexPtr() const
301     { return m_matrix.innerIndexPtr() + m_matrix.outerIndexPtr()[m_outerStart]; }
302 
outerIndexPtr()303     inline const Index* outerIndexPtr() const
304     { return m_matrix.outerIndexPtr() + m_outerStart; }
305 
nonZeros()306     Index nonZeros() const
307     {
308       if(m_matrix.isCompressed())
309         return  std::size_t(m_matrix.outerIndexPtr()[m_outerStart+m_outerSize.value()])
310               - std::size_t(m_matrix.outerIndexPtr()[m_outerStart]);
311       else if(m_outerSize.value()==0)
312         return 0;
313       else
314         return Map<const Matrix<Index,OuterSize,1> >(m_matrix.innerNonZeroPtr()+m_outerStart, m_outerSize.value()).sum();
315     }
316 
lastCoeff()317     const Scalar& lastCoeff() const
318     {
319       EIGEN_STATIC_ASSERT_VECTOR_ONLY(BlockImpl);
320       eigen_assert(nonZeros()>0);
321       if(m_matrix.isCompressed())
322         return m_matrix.valuePtr()[m_matrix.outerIndexPtr()[m_outerStart+1]-1];
323       else
324         return m_matrix.valuePtr()[m_matrix.outerIndexPtr()[m_outerStart]+m_matrix.innerNonZeroPtr()[m_outerStart]-1];
325     }
326 
rows()327     EIGEN_STRONG_INLINE Index rows() const { return IsRowMajor ? m_outerSize.value() : m_matrix.rows(); }
cols()328     EIGEN_STRONG_INLINE Index cols() const { return IsRowMajor ? m_matrix.cols() : m_outerSize.value(); }
329 
330   protected:
331 
332     typename SparseMatrixType::Nested m_matrix;
333     Index m_outerStart;
334     const internal::variable_if_dynamic<Index, OuterSize> m_outerSize;
335 
336 };
337 
338 //----------
339 
340 /** \returns the \a outer -th column (resp. row) of the matrix \c *this if \c *this
341   * is col-major (resp. row-major).
342   */
343 template<typename Derived>
innerVector(Index outer)344 typename SparseMatrixBase<Derived>::InnerVectorReturnType SparseMatrixBase<Derived>::innerVector(Index outer)
345 { return InnerVectorReturnType(derived(), outer); }
346 
347 /** \returns the \a outer -th column (resp. row) of the matrix \c *this if \c *this
348   * is col-major (resp. row-major). Read-only.
349   */
350 template<typename Derived>
innerVector(Index outer)351 const typename SparseMatrixBase<Derived>::ConstInnerVectorReturnType SparseMatrixBase<Derived>::innerVector(Index outer) const
352 { return ConstInnerVectorReturnType(derived(), outer); }
353 
354 /** \returns the \a outer -th column (resp. row) of the matrix \c *this if \c *this
355   * is col-major (resp. row-major).
356   */
357 template<typename Derived>
innerVectors(Index outerStart,Index outerSize)358 Block<Derived,Dynamic,Dynamic,true> SparseMatrixBase<Derived>::innerVectors(Index outerStart, Index outerSize)
359 {
360   return Block<Derived,Dynamic,Dynamic,true>(derived(),
361                                              IsRowMajor ? outerStart : 0, IsRowMajor ? 0 : outerStart,
362                                              IsRowMajor ? outerSize : rows(), IsRowMajor ? cols() : outerSize);
363 
364 }
365 
366 /** \returns the \a outer -th column (resp. row) of the matrix \c *this if \c *this
367   * is col-major (resp. row-major). Read-only.
368   */
369 template<typename Derived>
innerVectors(Index outerStart,Index outerSize)370 const Block<const Derived,Dynamic,Dynamic,true> SparseMatrixBase<Derived>::innerVectors(Index outerStart, Index outerSize) const
371 {
372   return Block<const Derived,Dynamic,Dynamic,true>(derived(),
373                                                   IsRowMajor ? outerStart : 0, IsRowMajor ? 0 : outerStart,
374                                                   IsRowMajor ? outerSize : rows(), IsRowMajor ? cols() : outerSize);
375 
376 }
377 
378 /** Generic implementation of sparse Block expression.
379   * Real-only.
380   */
381 template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
382 class BlockImpl<XprType,BlockRows,BlockCols,InnerPanel,Sparse>
383   : public SparseMatrixBase<Block<XprType,BlockRows,BlockCols,InnerPanel> >, internal::no_assignment_operator
384 {
385   typedef typename internal::remove_all<typename XprType::Nested>::type _MatrixTypeNested;
386   typedef Block<XprType, BlockRows, BlockCols, InnerPanel> BlockType;
387 public:
388     enum { IsRowMajor = internal::traits<BlockType>::IsRowMajor };
389     EIGEN_SPARSE_PUBLIC_INTERFACE(BlockType)
390 
391     /** Column or Row constructor
392       */
BlockImpl(const XprType & xpr,int i)393     inline BlockImpl(const XprType& xpr, int i)
394       : m_matrix(xpr),
395         m_startRow( (BlockRows==1) && (BlockCols==XprType::ColsAtCompileTime) ? i : 0),
396         m_startCol( (BlockRows==XprType::RowsAtCompileTime) && (BlockCols==1) ? i : 0),
397         m_blockRows(xpr.rows()),
398         m_blockCols(xpr.cols())
399     {}
400 
401     /** Dynamic-size constructor
402       */
BlockImpl(const XprType & xpr,int startRow,int startCol,int blockRows,int blockCols)403     inline BlockImpl(const XprType& xpr, int startRow, int startCol, int blockRows, int blockCols)
404       : m_matrix(xpr), m_startRow(startRow), m_startCol(startCol), m_blockRows(blockRows), m_blockCols(blockCols)
405     {}
406 
rows()407     inline int rows() const { return m_blockRows.value(); }
cols()408     inline int cols() const { return m_blockCols.value(); }
409 
coeffRef(int row,int col)410     inline Scalar& coeffRef(int row, int col)
411     {
412       return m_matrix.const_cast_derived()
413                .coeffRef(row + m_startRow.value(), col + m_startCol.value());
414     }
415 
coeff(int row,int col)416     inline const Scalar coeff(int row, int col) const
417     {
418       return m_matrix.coeff(row + m_startRow.value(), col + m_startCol.value());
419     }
420 
coeffRef(int index)421     inline Scalar& coeffRef(int index)
422     {
423       return m_matrix.const_cast_derived()
424              .coeffRef(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
425                        m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
426     }
427 
coeff(int index)428     inline const Scalar coeff(int index) const
429     {
430       return m_matrix
431              .coeff(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
432                     m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
433     }
434 
nestedExpression()435     inline const _MatrixTypeNested& nestedExpression() const { return m_matrix; }
436 
437     class InnerIterator : public _MatrixTypeNested::InnerIterator
438     {
439       typedef typename _MatrixTypeNested::InnerIterator Base;
440       const BlockType& m_block;
441       Index m_end;
442     public:
443 
InnerIterator(const BlockType & block,Index outer)444       EIGEN_STRONG_INLINE InnerIterator(const BlockType& block, Index outer)
445         : Base(block.derived().nestedExpression(), outer + (IsRowMajor ? block.m_startRow.value() : block.m_startCol.value())),
446           m_block(block),
447           m_end(IsRowMajor ? block.m_startCol.value()+block.m_blockCols.value() : block.m_startRow.value()+block.m_blockRows.value())
448       {
449         while( (Base::operator bool()) && (Base::index() < (IsRowMajor ? m_block.m_startCol.value() : m_block.m_startRow.value())) )
450           Base::operator++();
451       }
452 
index()453       inline Index index()  const { return Base::index() - (IsRowMajor ? m_block.m_startCol.value() : m_block.m_startRow.value()); }
outer()454       inline Index outer()  const { return Base::outer() - (IsRowMajor ? m_block.m_startRow.value() : m_block.m_startCol.value()); }
row()455       inline Index row()    const { return Base::row()   - m_block.m_startRow.value(); }
col()456       inline Index col()    const { return Base::col()   - m_block.m_startCol.value(); }
457 
458       inline operator bool() const { return Base::operator bool() && Base::index() < m_end; }
459     };
460     class ReverseInnerIterator : public _MatrixTypeNested::ReverseInnerIterator
461     {
462       typedef typename _MatrixTypeNested::ReverseInnerIterator Base;
463       const BlockType& m_block;
464       Index m_begin;
465     public:
466 
ReverseInnerIterator(const BlockType & block,Index outer)467       EIGEN_STRONG_INLINE ReverseInnerIterator(const BlockType& block, Index outer)
468         : Base(block.derived().nestedExpression(), outer + (IsRowMajor ? block.m_startRow.value() : block.m_startCol.value())),
469           m_block(block),
470           m_begin(IsRowMajor ? block.m_startCol.value() : block.m_startRow.value())
471       {
472         while( (Base::operator bool()) && (Base::index() >= (IsRowMajor ? m_block.m_startCol.value()+block.m_blockCols.value() : m_block.m_startRow.value()+block.m_blockRows.value())) )
473           Base::operator--();
474       }
475 
index()476       inline Index index()  const { return Base::index() - (IsRowMajor ? m_block.m_startCol.value() : m_block.m_startRow.value()); }
outer()477       inline Index outer()  const { return Base::outer() - (IsRowMajor ? m_block.m_startRow.value() : m_block.m_startCol.value()); }
row()478       inline Index row()    const { return Base::row()   - m_block.m_startRow.value(); }
col()479       inline Index col()    const { return Base::col()   - m_block.m_startCol.value(); }
480 
481       inline operator bool() const { return Base::operator bool() && Base::index() >= m_begin; }
482     };
483   protected:
484     friend class InnerIterator;
485     friend class ReverseInnerIterator;
486 
487     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl)
488 
489     typename XprType::Nested m_matrix;
490     const internal::variable_if_dynamic<Index, XprType::RowsAtCompileTime == 1 ? 0 : Dynamic> m_startRow;
491     const internal::variable_if_dynamic<Index, XprType::ColsAtCompileTime == 1 ? 0 : Dynamic> m_startCol;
492     const internal::variable_if_dynamic<Index, RowsAtCompileTime> m_blockRows;
493     const internal::variable_if_dynamic<Index, ColsAtCompileTime> m_blockCols;
494 
495 };
496 
497 } // end namespace Eigen
498 
499 #endif // EIGEN_SPARSE_BLOCK_H
500