| // This file is part of Eigen, a lightweight C++ template library | 
 | // for linear algebra. | 
 | // | 
 | // Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr> | 
 | // Copyright (C) 2012-2014 Gael Guennebaud <gael.guennebaud@inria.fr> | 
 | // | 
 | // This Source Code Form is subject to the terms of the Mozilla | 
 | // Public License v. 2.0. If a copy of the MPL was not distributed | 
 | // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. | 
 |  | 
 |  | 
 | #ifndef EIGEN_SPARSE_LU_H | 
 | #define EIGEN_SPARSE_LU_H | 
 |  | 
 | namespace Eigen { | 
 |  | 
 | template <typename _MatrixType, typename _OrderingType = COLAMDOrdering<typename _MatrixType::StorageIndex> > class SparseLU; | 
 | template <typename MappedSparseMatrixType> struct SparseLUMatrixLReturnType; | 
 | template <typename MatrixLType, typename MatrixUType> struct SparseLUMatrixUReturnType; | 
 |  | 
 | /** \ingroup SparseLU_Module | 
 |   * \class SparseLU | 
 |   *  | 
 |   * \brief Sparse supernodal LU factorization for general matrices | 
 |   *  | 
 |   * This class implements the supernodal LU factorization for general matrices. | 
 |   * It uses the main techniques from the sequential SuperLU package  | 
 |   * (http://crd-legacy.lbl.gov/~xiaoye/SuperLU/). It handles transparently real  | 
 |   * and complex arithmetics with single and double precision, depending on the  | 
 |   * scalar type of your input matrix.  | 
 |   * The code has been optimized to provide BLAS-3 operations during supernode-panel updates.  | 
 |   * It benefits directly from the built-in high-performant Eigen BLAS routines.  | 
 |   * Moreover, when the size of a supernode is very small, the BLAS calls are avoided to  | 
 |   * enable a better optimization from the compiler. For best performance,  | 
 |   * you should compile it with NDEBUG flag to avoid the numerous bounds checking on vectors.  | 
 |   *  | 
 |   * An important parameter of this class is the ordering method. It is used to reorder the columns  | 
 |   * (and eventually the rows) of the matrix to reduce the number of new elements that are created during  | 
 |   * numerical factorization. The cheapest method available is COLAMD.  | 
 |   * See  \link OrderingMethods_Module the OrderingMethods module \endlink for the list of  | 
 |   * built-in and external ordering methods.  | 
 |   * | 
 |   * Simple example with key steps  | 
 |   * \code | 
 |   * VectorXd x(n), b(n); | 
 |   * SparseMatrix<double, ColMajor> A; | 
 |   * SparseLU<SparseMatrix<scalar, ColMajor>, COLAMDOrdering<Index> >   solver; | 
 |   * // fill A and b; | 
 |   * // Compute the ordering permutation vector from the structural pattern of A | 
 |   * solver.analyzePattern(A);  | 
 |   * // Compute the numerical factorization  | 
 |   * solver.factorize(A);  | 
 |   * //Use the factors to solve the linear system  | 
 |   * x = solver.solve(b);  | 
 |   * \endcode | 
 |   *  | 
 |   * \warning The input matrix A should be in a \b compressed and \b column-major form. | 
 |   * Otherwise an expensive copy will be made. You can call the inexpensive makeCompressed() to get a compressed matrix. | 
 |   *  | 
 |   * \note Unlike the initial SuperLU implementation, there is no step to equilibrate the matrix.  | 
 |   * For badly scaled matrices, this step can be useful to reduce the pivoting during factorization.  | 
 |   * If this is the case for your matrices, you can try the basic scaling method at | 
 |   *  "unsupported/Eigen/src/IterativeSolvers/Scaling.h" | 
 |   *  | 
 |   * \tparam _MatrixType The type of the sparse matrix. It must be a column-major SparseMatrix<> | 
 |   * \tparam _OrderingType The ordering method to use, either AMD, COLAMD or METIS. Default is COLMAD | 
 |   *  | 
 |   *  | 
 |   * \sa \ref TutorialSparseDirectSolvers | 
 |   * \sa \ref OrderingMethods_Module | 
 |   */ | 
 | template <typename _MatrixType, typename _OrderingType> | 
 | class SparseLU : public SparseSolverBase<SparseLU<_MatrixType,_OrderingType> >, public internal::SparseLUImpl<typename _MatrixType::Scalar, typename _MatrixType::StorageIndex> | 
 | { | 
 |   protected: | 
 |     typedef SparseSolverBase<SparseLU<_MatrixType,_OrderingType> > APIBase; | 
 |     using APIBase::m_isInitialized; | 
 |   public: | 
 |     using APIBase::_solve_impl; | 
 |      | 
 |     typedef _MatrixType MatrixType;  | 
 |     typedef _OrderingType OrderingType; | 
 |     typedef typename MatrixType::Scalar Scalar;  | 
 |     typedef typename MatrixType::RealScalar RealScalar;  | 
 |     typedef typename MatrixType::StorageIndex StorageIndex; | 
 |     typedef SparseMatrix<Scalar,ColMajor,StorageIndex> NCMatrix; | 
 |     typedef internal::MappedSuperNodalMatrix<Scalar, StorageIndex> SCMatrix; | 
 |     typedef Matrix<Scalar,Dynamic,1> ScalarVector; | 
 |     typedef Matrix<StorageIndex,Dynamic,1> IndexVector; | 
 |     typedef PermutationMatrix<Dynamic, Dynamic, StorageIndex> PermutationType; | 
 |     typedef internal::SparseLUImpl<Scalar, StorageIndex> Base; | 
 |      | 
 |   public: | 
 |     SparseLU():m_lastError(""),m_Ustore(0,0,0,0,0,0),m_symmetricmode(false),m_diagpivotthresh(1.0),m_detPermR(1) | 
 |     { | 
 |       initperfvalues();  | 
 |     } | 
 |     explicit SparseLU(const MatrixType& matrix):m_lastError(""),m_Ustore(0,0,0,0,0,0),m_symmetricmode(false),m_diagpivotthresh(1.0),m_detPermR(1) | 
 |     { | 
 |       initperfvalues();  | 
 |       compute(matrix); | 
 |     } | 
 |      | 
 |     ~SparseLU() | 
 |     { | 
 |       // Free all explicit dynamic pointers  | 
 |     } | 
 |      | 
 |     void analyzePattern (const MatrixType& matrix); | 
 |     void factorize (const MatrixType& matrix); | 
 |     void simplicialfactorize(const MatrixType& matrix); | 
 |      | 
 |     /** | 
 |       * Compute the symbolic and numeric factorization of the input sparse matrix. | 
 |       * The input matrix should be in column-major storage.  | 
 |       */ | 
 |     void compute (const MatrixType& matrix) | 
 |     { | 
 |       // Analyze  | 
 |       analyzePattern(matrix);  | 
 |       //Factorize | 
 |       factorize(matrix); | 
 |     }  | 
 |      | 
 |     inline Index rows() const { return m_mat.rows(); } | 
 |     inline Index cols() const { return m_mat.cols(); } | 
 |     /** Indicate that the pattern of the input matrix is symmetric */ | 
 |     void isSymmetric(bool sym) | 
 |     { | 
 |       m_symmetricmode = sym; | 
 |     } | 
 |      | 
 |     /** \returns an expression of the matrix L, internally stored as supernodes | 
 |       * The only operation available with this expression is the triangular solve | 
 |       * \code | 
 |       * y = b; matrixL().solveInPlace(y); | 
 |       * \endcode | 
 |       */ | 
 |     SparseLUMatrixLReturnType<SCMatrix> matrixL() const | 
 |     { | 
 |       return SparseLUMatrixLReturnType<SCMatrix>(m_Lstore); | 
 |     } | 
 |     /** \returns an expression of the matrix U, | 
 |       * The only operation available with this expression is the triangular solve | 
 |       * \code | 
 |       * y = b; matrixU().solveInPlace(y); | 
 |       * \endcode | 
 |       */ | 
 |     SparseLUMatrixUReturnType<SCMatrix,MappedSparseMatrix<Scalar,ColMajor,StorageIndex> > matrixU() const | 
 |     { | 
 |       return SparseLUMatrixUReturnType<SCMatrix, MappedSparseMatrix<Scalar,ColMajor,StorageIndex> >(m_Lstore, m_Ustore); | 
 |     } | 
 |  | 
 |     /** | 
 |       * \returns a reference to the row matrix permutation \f$ P_r \f$ such that \f$P_r A P_c^T = L U\f$ | 
 |       * \sa colsPermutation() | 
 |       */ | 
 |     inline const PermutationType& rowsPermutation() const | 
 |     { | 
 |       return m_perm_r; | 
 |     } | 
 |     /** | 
 |       * \returns a reference to the column matrix permutation\f$ P_c^T \f$ such that \f$P_r A P_c^T = L U\f$ | 
 |       * \sa rowsPermutation() | 
 |       */ | 
 |     inline const PermutationType& colsPermutation() const | 
 |     { | 
 |       return m_perm_c; | 
 |     } | 
 |     /** Set the threshold used for a diagonal entry to be an acceptable pivot. */ | 
 |     void setPivotThreshold(const RealScalar& thresh) | 
 |     { | 
 |       m_diagpivotthresh = thresh;  | 
 |     } | 
 |  | 
 | #ifdef EIGEN_PARSED_BY_DOXYGEN | 
 |     /** \returns the solution X of \f$ A X = B \f$ using the current decomposition of A. | 
 |       * | 
 |       * \warning the destination matrix X in X = this->solve(B) must be colmun-major. | 
 |       * | 
 |       * \sa compute() | 
 |       */ | 
 |     template<typename Rhs> | 
 |     inline const Solve<SparseLU, Rhs> solve(const MatrixBase<Rhs>& B) const; | 
 | #endif // EIGEN_PARSED_BY_DOXYGEN | 
 |      | 
 |     /** \brief Reports whether previous computation was successful. | 
 |       * | 
 |       * \returns \c Success if computation was succesful, | 
 |       *          \c NumericalIssue if the LU factorization reports a problem, zero diagonal for instance | 
 |       *          \c InvalidInput if the input matrix is invalid | 
 |       * | 
 |       * \sa iparm()           | 
 |       */ | 
 |     ComputationInfo info() const | 
 |     { | 
 |       eigen_assert(m_isInitialized && "Decomposition is not initialized."); | 
 |       return m_info; | 
 |     } | 
 |      | 
 |     /** | 
 |       * \returns A string describing the type of error | 
 |       */ | 
 |     std::string lastErrorMessage() const | 
 |     { | 
 |       return m_lastError;  | 
 |     } | 
 |  | 
 |     template<typename Rhs, typename Dest> | 
 |     bool _solve_impl(const MatrixBase<Rhs> &B, MatrixBase<Dest> &X_base) const | 
 |     { | 
 |       Dest& X(X_base.derived()); | 
 |       eigen_assert(m_factorizationIsOk && "The matrix should be factorized first"); | 
 |       EIGEN_STATIC_ASSERT((Dest::Flags&RowMajorBit)==0, | 
 |                         THIS_METHOD_IS_ONLY_FOR_COLUMN_MAJOR_MATRICES); | 
 |        | 
 |       // Permute the right hand side to form X = Pr*B | 
 |       // on return, X is overwritten by the computed solution | 
 |       X.resize(B.rows(),B.cols()); | 
 |  | 
 |       // this ugly const_cast_derived() helps to detect aliasing when applying the permutations | 
 |       for(Index j = 0; j < B.cols(); ++j) | 
 |         X.col(j) = rowsPermutation() * B.const_cast_derived().col(j); | 
 |        | 
 |       //Forward substitution with L | 
 |       this->matrixL().solveInPlace(X); | 
 |       this->matrixU().solveInPlace(X); | 
 |        | 
 |       // Permute back the solution  | 
 |       for (Index j = 0; j < B.cols(); ++j) | 
 |         X.col(j) = colsPermutation().inverse() * X.col(j); | 
 |        | 
 |       return true;  | 
 |     } | 
 |      | 
 |     /** | 
 |       * \returns the absolute value of the determinant of the matrix of which | 
 |       * *this is the QR decomposition. | 
 |       * | 
 |       * \warning a determinant can be very big or small, so for matrices | 
 |       * of large enough dimension, there is a risk of overflow/underflow. | 
 |       * One way to work around that is to use logAbsDeterminant() instead. | 
 |       * | 
 |       * \sa logAbsDeterminant(), signDeterminant() | 
 |       */ | 
 |     Scalar absDeterminant() | 
 |     { | 
 |       using std::abs; | 
 |       eigen_assert(m_factorizationIsOk && "The matrix should be factorized first."); | 
 |       // Initialize with the determinant of the row matrix | 
 |       Scalar det = Scalar(1.); | 
 |       // Note that the diagonal blocks of U are stored in supernodes, | 
 |       // which are available in the  L part :) | 
 |       for (Index j = 0; j < this->cols(); ++j) | 
 |       { | 
 |         for (typename SCMatrix::InnerIterator it(m_Lstore, j); it; ++it) | 
 |         { | 
 |           if(it.index() == j) | 
 |           { | 
 |             det *= abs(it.value()); | 
 |             break; | 
 |           } | 
 |         } | 
 |       } | 
 |       return det; | 
 |     } | 
 |  | 
 |     /** \returns the natural log of the absolute value of the determinant of the matrix | 
 |       * of which **this is the QR decomposition | 
 |       * | 
 |       * \note This method is useful to work around the risk of overflow/underflow that's | 
 |       * inherent to the determinant computation. | 
 |       * | 
 |       * \sa absDeterminant(), signDeterminant() | 
 |       */ | 
 |     Scalar logAbsDeterminant() const | 
 |     { | 
 |       using std::log; | 
 |       using std::abs; | 
 |  | 
 |       eigen_assert(m_factorizationIsOk && "The matrix should be factorized first."); | 
 |       Scalar det = Scalar(0.); | 
 |       for (Index j = 0; j < this->cols(); ++j) | 
 |       { | 
 |         for (typename SCMatrix::InnerIterator it(m_Lstore, j); it; ++it) | 
 |         { | 
 |           if(it.row() < j) continue; | 
 |           if(it.row() == j) | 
 |           { | 
 |             det += log(abs(it.value())); | 
 |             break; | 
 |           } | 
 |         } | 
 |       } | 
 |       return det; | 
 |     } | 
 |  | 
 |     /** \returns A number representing the sign of the determinant | 
 |       * | 
 |       * \sa absDeterminant(), logAbsDeterminant() | 
 |       */ | 
 |     Scalar signDeterminant() | 
 |     { | 
 |       eigen_assert(m_factorizationIsOk && "The matrix should be factorized first."); | 
 |       // Initialize with the determinant of the row matrix | 
 |       Index det = 1; | 
 |       // Note that the diagonal blocks of U are stored in supernodes, | 
 |       // which are available in the  L part :) | 
 |       for (Index j = 0; j < this->cols(); ++j) | 
 |       { | 
 |         for (typename SCMatrix::InnerIterator it(m_Lstore, j); it; ++it) | 
 |         { | 
 |           if(it.index() == j) | 
 |           { | 
 |             if(it.value()<0) | 
 |               det = -det; | 
 |             else if(it.value()==0) | 
 |               return 0; | 
 |             break; | 
 |           } | 
 |         } | 
 |       } | 
 |       return det * m_detPermR * m_detPermC; | 
 |     } | 
 |      | 
 |     /** \returns The determinant of the matrix. | 
 |       * | 
 |       * \sa absDeterminant(), logAbsDeterminant() | 
 |       */ | 
 |     Scalar determinant() | 
 |     { | 
 |       eigen_assert(m_factorizationIsOk && "The matrix should be factorized first."); | 
 |       // Initialize with the determinant of the row matrix | 
 |       Scalar det = Scalar(1.); | 
 |       // Note that the diagonal blocks of U are stored in supernodes, | 
 |       // which are available in the  L part :) | 
 |       for (Index j = 0; j < this->cols(); ++j) | 
 |       { | 
 |         for (typename SCMatrix::InnerIterator it(m_Lstore, j); it; ++it) | 
 |         { | 
 |           if(it.index() == j) | 
 |           { | 
 |             det *= it.value(); | 
 |             break; | 
 |           } | 
 |         } | 
 |       } | 
 |       return (m_detPermR * m_detPermC) > 0 ? det : -det; | 
 |     } | 
 |  | 
 |   protected: | 
 |     // Functions  | 
 |     void initperfvalues() | 
 |     { | 
 |       m_perfv.panel_size = 16; | 
 |       m_perfv.relax = 1;  | 
 |       m_perfv.maxsuper = 128;  | 
 |       m_perfv.rowblk = 16;  | 
 |       m_perfv.colblk = 8;  | 
 |       m_perfv.fillfactor = 20;   | 
 |     } | 
 |        | 
 |     // Variables  | 
 |     mutable ComputationInfo m_info; | 
 |     bool m_factorizationIsOk; | 
 |     bool m_analysisIsOk; | 
 |     std::string m_lastError; | 
 |     NCMatrix m_mat; // The input (permuted ) matrix  | 
 |     SCMatrix m_Lstore; // The lower triangular matrix (supernodal) | 
 |     MappedSparseMatrix<Scalar,ColMajor,StorageIndex> m_Ustore; // The upper triangular matrix | 
 |     PermutationType m_perm_c; // Column permutation  | 
 |     PermutationType m_perm_r ; // Row permutation | 
 |     IndexVector m_etree; // Column elimination tree  | 
 |      | 
 |     typename Base::GlobalLU_t m_glu;  | 
 |                                 | 
 |     // SparseLU options  | 
 |     bool m_symmetricmode; | 
 |     // values for performance  | 
 |     internal::perfvalues m_perfv; | 
 |     RealScalar m_diagpivotthresh; // Specifies the threshold used for a diagonal entry to be an acceptable pivot | 
 |     Index m_nnzL, m_nnzU; // Nonzeros in L and U factors | 
 |     Index m_detPermR, m_detPermC; // Determinants of the permutation matrices | 
 |   private: | 
 |     // Disable copy constructor  | 
 |     SparseLU (const SparseLU& ); | 
 |    | 
 | }; // End class SparseLU | 
 |  | 
 |  | 
 |  | 
 | // Functions needed by the anaysis phase | 
 | /**  | 
 |   * Compute the column permutation to minimize the fill-in | 
 |   *  | 
 |   *  - Apply this permutation to the input matrix -  | 
 |   *  | 
 |   *  - Compute the column elimination tree on the permuted matrix  | 
 |   *  | 
 |   *  - Postorder the elimination tree and the column permutation | 
 |   *  | 
 |   */ | 
 | template <typename MatrixType, typename OrderingType> | 
 | void SparseLU<MatrixType, OrderingType>::analyzePattern(const MatrixType& mat) | 
 | { | 
 |    | 
 |   //TODO  It is possible as in SuperLU to compute row and columns scaling vectors to equilibrate the matrix mat. | 
 |    | 
 |   // Firstly, copy the whole input matrix.  | 
 |   m_mat = mat; | 
 |    | 
 |   // Compute fill-in ordering | 
 |   OrderingType ord;  | 
 |   ord(m_mat,m_perm_c); | 
 |    | 
 |   // Apply the permutation to the column of the input  matrix | 
 |   if (m_perm_c.size()) | 
 |   { | 
 |     m_mat.uncompress(); //NOTE: The effect of this command is only to create the InnerNonzeros pointers. FIXME : This vector is filled but not subsequently used.   | 
 |     // Then, permute only the column pointers | 
 |     ei_declare_aligned_stack_constructed_variable(StorageIndex,outerIndexPtr,mat.cols()+1,mat.isCompressed()?const_cast<StorageIndex*>(mat.outerIndexPtr()):0); | 
 |      | 
 |     // If the input matrix 'mat' is uncompressed, then the outer-indices do not match the ones of m_mat, and a copy is thus needed. | 
 |     if(!mat.isCompressed())  | 
 |       IndexVector::Map(outerIndexPtr, mat.cols()+1) = IndexVector::Map(m_mat.outerIndexPtr(),mat.cols()+1); | 
 |      | 
 |     // Apply the permutation and compute the nnz per column. | 
 |     for (Index i = 0; i < mat.cols(); i++) | 
 |     { | 
 |       m_mat.outerIndexPtr()[m_perm_c.indices()(i)] = outerIndexPtr[i]; | 
 |       m_mat.innerNonZeroPtr()[m_perm_c.indices()(i)] = outerIndexPtr[i+1] - outerIndexPtr[i]; | 
 |     } | 
 |   } | 
 |    | 
 |   // Compute the column elimination tree of the permuted matrix  | 
 |   IndexVector firstRowElt; | 
 |   internal::coletree(m_mat, m_etree,firstRowElt);  | 
 |       | 
 |   // In symmetric mode, do not do postorder here | 
 |   if (!m_symmetricmode) { | 
 |     IndexVector post, iwork;  | 
 |     // Post order etree | 
 |     internal::treePostorder(StorageIndex(m_mat.cols()), m_etree, post);  | 
 |        | 
 |     | 
 |     // Renumber etree in postorder  | 
 |     Index m = m_mat.cols();  | 
 |     iwork.resize(m+1); | 
 |     for (Index i = 0; i < m; ++i) iwork(post(i)) = post(m_etree(i)); | 
 |     m_etree = iwork; | 
 |      | 
 |     // Postmultiply A*Pc by post, i.e reorder the matrix according to the postorder of the etree | 
 |     PermutationType post_perm(m);  | 
 |     for (Index i = 0; i < m; i++)  | 
 |       post_perm.indices()(i) = post(i);  | 
 |          | 
 |     // Combine the two permutations : postorder the permutation for future use | 
 |     if(m_perm_c.size()) { | 
 |       m_perm_c = post_perm * m_perm_c; | 
 |     } | 
 |      | 
 |   } // end postordering  | 
 |    | 
 |   m_analysisIsOk = true;  | 
 | } | 
 |  | 
 | // Functions needed by the numerical factorization phase | 
 |  | 
 |  | 
 | /**  | 
 |   *  - Numerical factorization  | 
 |   *  - Interleaved with the symbolic factorization  | 
 |   * On exit,  info is  | 
 |   *  | 
 |   *    = 0: successful factorization | 
 |   *  | 
 |   *    > 0: if info = i, and i is | 
 |   *  | 
 |   *       <= A->ncol: U(i,i) is exactly zero. The factorization has | 
 |   *          been completed, but the factor U is exactly singular, | 
 |   *          and division by zero will occur if it is used to solve a | 
 |   *          system of equations. | 
 |   *  | 
 |   *       > A->ncol: number of bytes allocated when memory allocation | 
 |   *         failure occurred, plus A->ncol. If lwork = -1, it is | 
 |   *         the estimated amount of space needed, plus A->ncol.   | 
 |   */ | 
 | template <typename MatrixType, typename OrderingType> | 
 | void SparseLU<MatrixType, OrderingType>::factorize(const MatrixType& matrix) | 
 | { | 
 |   using internal::emptyIdxLU; | 
 |   eigen_assert(m_analysisIsOk && "analyzePattern() should be called first");  | 
 |   eigen_assert((matrix.rows() == matrix.cols()) && "Only for squared matrices"); | 
 |    | 
 |   typedef typename IndexVector::Scalar StorageIndex;  | 
 |    | 
 |   m_isInitialized = true; | 
 |    | 
 |    | 
 |   // Apply the column permutation computed in analyzepattern() | 
 |   //   m_mat = matrix * m_perm_c.inverse();  | 
 |   m_mat = matrix; | 
 |   if (m_perm_c.size())  | 
 |   { | 
 |     m_mat.uncompress(); //NOTE: The effect of this command is only to create the InnerNonzeros pointers. | 
 |     //Then, permute only the column pointers | 
 |     const StorageIndex * outerIndexPtr; | 
 |     if (matrix.isCompressed()) outerIndexPtr = matrix.outerIndexPtr(); | 
 |     else | 
 |     { | 
 |       StorageIndex* outerIndexPtr_t = new StorageIndex[matrix.cols()+1]; | 
 |       for(Index i = 0; i <= matrix.cols(); i++) outerIndexPtr_t[i] = m_mat.outerIndexPtr()[i]; | 
 |       outerIndexPtr = outerIndexPtr_t; | 
 |     } | 
 |     for (Index i = 0; i < matrix.cols(); i++) | 
 |     { | 
 |       m_mat.outerIndexPtr()[m_perm_c.indices()(i)] = outerIndexPtr[i]; | 
 |       m_mat.innerNonZeroPtr()[m_perm_c.indices()(i)] = outerIndexPtr[i+1] - outerIndexPtr[i]; | 
 |     } | 
 |     if(!matrix.isCompressed()) delete[] outerIndexPtr; | 
 |   }  | 
 |   else  | 
 |   { //FIXME This should not be needed if the empty permutation is handled transparently | 
 |     m_perm_c.resize(matrix.cols()); | 
 |     for(StorageIndex i = 0; i < matrix.cols(); ++i) m_perm_c.indices()(i) = i; | 
 |   } | 
 |    | 
 |   Index m = m_mat.rows(); | 
 |   Index n = m_mat.cols(); | 
 |   Index nnz = m_mat.nonZeros(); | 
 |   Index maxpanel = m_perfv.panel_size * m; | 
 |   // Allocate working storage common to the factor routines | 
 |   Index lwork = 0; | 
 |   Index info = Base::memInit(m, n, nnz, lwork, m_perfv.fillfactor, m_perfv.panel_size, m_glu);  | 
 |   if (info)  | 
 |   { | 
 |     m_lastError = "UNABLE TO ALLOCATE WORKING MEMORY\n\n" ; | 
 |     m_factorizationIsOk = false; | 
 |     return ;  | 
 |   } | 
 |    | 
 |   // Set up pointers for integer working arrays  | 
 |   IndexVector segrep(m); segrep.setZero(); | 
 |   IndexVector parent(m); parent.setZero(); | 
 |   IndexVector xplore(m); xplore.setZero(); | 
 |   IndexVector repfnz(maxpanel); | 
 |   IndexVector panel_lsub(maxpanel); | 
 |   IndexVector xprune(n); xprune.setZero(); | 
 |   IndexVector marker(m*internal::LUNoMarker); marker.setZero(); | 
 |    | 
 |   repfnz.setConstant(-1);  | 
 |   panel_lsub.setConstant(-1); | 
 |    | 
 |   // Set up pointers for scalar working arrays  | 
 |   ScalarVector dense;  | 
 |   dense.setZero(maxpanel); | 
 |   ScalarVector tempv;  | 
 |   tempv.setZero(internal::LUnumTempV(m, m_perfv.panel_size, m_perfv.maxsuper, /*m_perfv.rowblk*/m) ); | 
 |    | 
 |   // Compute the inverse of perm_c | 
 |   PermutationType iperm_c(m_perm_c.inverse());  | 
 |    | 
 |   // Identify initial relaxed snodes | 
 |   IndexVector relax_end(n); | 
 |   if ( m_symmetricmode == true )  | 
 |     Base::heap_relax_snode(n, m_etree, m_perfv.relax, marker, relax_end); | 
 |   else | 
 |     Base::relax_snode(n, m_etree, m_perfv.relax, marker, relax_end); | 
 |    | 
 |    | 
 |   m_perm_r.resize(m);  | 
 |   m_perm_r.indices().setConstant(-1); | 
 |   marker.setConstant(-1); | 
 |   m_detPermR = 1; // Record the determinant of the row permutation | 
 |    | 
 |   m_glu.supno(0) = emptyIdxLU; m_glu.xsup.setConstant(0); | 
 |   m_glu.xsup(0) = m_glu.xlsub(0) = m_glu.xusub(0) = m_glu.xlusup(0) = Index(0); | 
 |    | 
 |   // Work on one 'panel' at a time. A panel is one of the following : | 
 |   //  (a) a relaxed supernode at the bottom of the etree, or | 
 |   //  (b) panel_size contiguous columns, <panel_size> defined by the user | 
 |   Index jcol;  | 
 |   IndexVector panel_histo(n); | 
 |   Index pivrow; // Pivotal row number in the original row matrix | 
 |   Index nseg1; // Number of segments in U-column above panel row jcol | 
 |   Index nseg; // Number of segments in each U-column  | 
 |   Index irep;  | 
 |   Index i, k, jj;  | 
 |   for (jcol = 0; jcol < n; ) | 
 |   { | 
 |     // Adjust panel size so that a panel won't overlap with the next relaxed snode.  | 
 |     Index panel_size = m_perfv.panel_size; // upper bound on panel width | 
 |     for (k = jcol + 1; k < (std::min)(jcol+panel_size, n); k++) | 
 |     { | 
 |       if (relax_end(k) != emptyIdxLU)  | 
 |       { | 
 |         panel_size = k - jcol;  | 
 |         break;  | 
 |       } | 
 |     } | 
 |     if (k == n)  | 
 |       panel_size = n - jcol;  | 
 |        | 
 |     // Symbolic outer factorization on a panel of columns  | 
 |     Base::panel_dfs(m, panel_size, jcol, m_mat, m_perm_r.indices(), nseg1, dense, panel_lsub, segrep, repfnz, xprune, marker, parent, xplore, m_glu);  | 
 |      | 
 |     // Numeric sup-panel updates in topological order  | 
 |     Base::panel_bmod(m, panel_size, jcol, nseg1, dense, tempv, segrep, repfnz, m_glu);  | 
 |      | 
 |     // Sparse LU within the panel, and below the panel diagonal  | 
 |     for ( jj = jcol; jj< jcol + panel_size; jj++)  | 
 |     { | 
 |       k = (jj - jcol) * m; // Column index for w-wide arrays  | 
 |        | 
 |       nseg = nseg1; // begin after all the panel segments | 
 |       //Depth-first-search for the current column | 
 |       VectorBlock<IndexVector> panel_lsubk(panel_lsub, k, m); | 
 |       VectorBlock<IndexVector> repfnz_k(repfnz, k, m);  | 
 |       info = Base::column_dfs(m, jj, m_perm_r.indices(), m_perfv.maxsuper, nseg, panel_lsubk, segrep, repfnz_k, xprune, marker, parent, xplore, m_glu);  | 
 |       if ( info )  | 
 |       { | 
 |         m_lastError =  "UNABLE TO EXPAND MEMORY IN COLUMN_DFS() "; | 
 |         m_info = NumericalIssue;  | 
 |         m_factorizationIsOk = false;  | 
 |         return;  | 
 |       } | 
 |       // Numeric updates to this column  | 
 |       VectorBlock<ScalarVector> dense_k(dense, k, m);  | 
 |       VectorBlock<IndexVector> segrep_k(segrep, nseg1, m-nseg1);  | 
 |       info = Base::column_bmod(jj, (nseg - nseg1), dense_k, tempv, segrep_k, repfnz_k, jcol, m_glu);  | 
 |       if ( info )  | 
 |       { | 
 |         m_lastError = "UNABLE TO EXPAND MEMORY IN COLUMN_BMOD() "; | 
 |         m_info = NumericalIssue;  | 
 |         m_factorizationIsOk = false;  | 
 |         return;  | 
 |       } | 
 |        | 
 |       // Copy the U-segments to ucol(*) | 
 |       info = Base::copy_to_ucol(jj, nseg, segrep, repfnz_k ,m_perm_r.indices(), dense_k, m_glu);  | 
 |       if ( info )  | 
 |       { | 
 |         m_lastError = "UNABLE TO EXPAND MEMORY IN COPY_TO_UCOL() "; | 
 |         m_info = NumericalIssue;  | 
 |         m_factorizationIsOk = false;  | 
 |         return;  | 
 |       } | 
 |        | 
 |       // Form the L-segment  | 
 |       info = Base::pivotL(jj, m_diagpivotthresh, m_perm_r.indices(), iperm_c.indices(), pivrow, m_glu); | 
 |       if ( info )  | 
 |       { | 
 |         m_lastError = "THE MATRIX IS STRUCTURALLY SINGULAR ... ZERO COLUMN AT "; | 
 |         std::ostringstream returnInfo; | 
 |         returnInfo << info;  | 
 |         m_lastError += returnInfo.str(); | 
 |         m_info = NumericalIssue;  | 
 |         m_factorizationIsOk = false;  | 
 |         return;  | 
 |       } | 
 |        | 
 |       // Update the determinant of the row permutation matrix | 
 |       // FIXME: the following test is not correct, we should probably take iperm_c into account and pivrow is not directly the row pivot. | 
 |       if (pivrow != jj) m_detPermR = -m_detPermR; | 
 |  | 
 |       // Prune columns (0:jj-1) using column jj | 
 |       Base::pruneL(jj, m_perm_r.indices(), pivrow, nseg, segrep, repfnz_k, xprune, m_glu);  | 
 |        | 
 |       // Reset repfnz for this column  | 
 |       for (i = 0; i < nseg; i++) | 
 |       { | 
 |         irep = segrep(i);  | 
 |         repfnz_k(irep) = emptyIdxLU;  | 
 |       } | 
 |     } // end SparseLU within the panel   | 
 |     jcol += panel_size;  // Move to the next panel | 
 |   } // end for -- end elimination  | 
 |    | 
 |   m_detPermR = m_perm_r.determinant(); | 
 |   m_detPermC = m_perm_c.determinant(); | 
 |    | 
 |   // Count the number of nonzeros in factors  | 
 |   Base::countnz(n, m_nnzL, m_nnzU, m_glu);  | 
 |   // Apply permutation  to the L subscripts  | 
 |   Base::fixupL(n, m_perm_r.indices(), m_glu); | 
 |    | 
 |   // Create supernode matrix L  | 
 |   m_Lstore.setInfos(m, n, m_glu.lusup, m_glu.xlusup, m_glu.lsub, m_glu.xlsub, m_glu.supno, m_glu.xsup);  | 
 |   // Create the column major upper sparse matrix  U;  | 
 |   new (&m_Ustore) MappedSparseMatrix<Scalar, ColMajor, StorageIndex> ( m, n, m_nnzU, m_glu.xusub.data(), m_glu.usub.data(), m_glu.ucol.data() ); | 
 |    | 
 |   m_info = Success; | 
 |   m_factorizationIsOk = true; | 
 | } | 
 |  | 
 | template<typename MappedSupernodalType> | 
 | struct SparseLUMatrixLReturnType : internal::no_assignment_operator | 
 | { | 
 |   typedef typename MappedSupernodalType::Scalar Scalar; | 
 |   explicit SparseLUMatrixLReturnType(const MappedSupernodalType& mapL) : m_mapL(mapL) | 
 |   { } | 
 |   Index rows() { return m_mapL.rows(); } | 
 |   Index cols() { return m_mapL.cols(); } | 
 |   template<typename Dest> | 
 |   void solveInPlace( MatrixBase<Dest> &X) const | 
 |   { | 
 |     m_mapL.solveInPlace(X); | 
 |   } | 
 |   const MappedSupernodalType& m_mapL; | 
 | }; | 
 |  | 
 | template<typename MatrixLType, typename MatrixUType> | 
 | struct SparseLUMatrixUReturnType : internal::no_assignment_operator | 
 | { | 
 |   typedef typename MatrixLType::Scalar Scalar; | 
 |   explicit SparseLUMatrixUReturnType(const MatrixLType& mapL, const MatrixUType& mapU) | 
 |   : m_mapL(mapL),m_mapU(mapU) | 
 |   { } | 
 |   Index rows() { return m_mapL.rows(); } | 
 |   Index cols() { return m_mapL.cols(); } | 
 |  | 
 |   template<typename Dest>   void solveInPlace(MatrixBase<Dest> &X) const | 
 |   { | 
 |     Index nrhs = X.cols(); | 
 |     Index n    = X.rows(); | 
 |     // Backward solve with U | 
 |     for (Index k = m_mapL.nsuper(); k >= 0; k--) | 
 |     { | 
 |       Index fsupc = m_mapL.supToCol()[k]; | 
 |       Index lda = m_mapL.colIndexPtr()[fsupc+1] - m_mapL.colIndexPtr()[fsupc]; // leading dimension | 
 |       Index nsupc = m_mapL.supToCol()[k+1] - fsupc; | 
 |       Index luptr = m_mapL.colIndexPtr()[fsupc]; | 
 |  | 
 |       if (nsupc == 1) | 
 |       { | 
 |         for (Index j = 0; j < nrhs; j++) | 
 |         { | 
 |           X(fsupc, j) /= m_mapL.valuePtr()[luptr]; | 
 |         } | 
 |       } | 
 |       else | 
 |       { | 
 |         Map<const Matrix<Scalar,Dynamic,Dynamic, ColMajor>, 0, OuterStride<> > A( &(m_mapL.valuePtr()[luptr]), nsupc, nsupc, OuterStride<>(lda) ); | 
 |         Map< Matrix<Scalar,Dynamic,Dynamic, ColMajor>, 0, OuterStride<> > U (&(X(fsupc,0)), nsupc, nrhs, OuterStride<>(n) ); | 
 |         U = A.template triangularView<Upper>().solve(U); | 
 |       } | 
 |  | 
 |       for (Index j = 0; j < nrhs; ++j) | 
 |       { | 
 |         for (Index jcol = fsupc; jcol < fsupc + nsupc; jcol++) | 
 |         { | 
 |           typename MatrixUType::InnerIterator it(m_mapU, jcol); | 
 |           for ( ; it; ++it) | 
 |           { | 
 |             Index irow = it.index(); | 
 |             X(irow, j) -= X(jcol, j) * it.value(); | 
 |           } | 
 |         } | 
 |       } | 
 |     } // End For U-solve | 
 |   } | 
 |   const MatrixLType& m_mapL; | 
 |   const MatrixUType& m_mapU; | 
 | }; | 
 |  | 
 | } // End namespace Eigen  | 
 |  | 
 | #endif |