MatLUFactor

Performs in-place LU factorization of matrix.

Synopsis

#include "petscmat.h" 
PetscErrorCode MatLUFactor(Mat mat, IS row, IS col, const MatFactorInfo *info)

Collective

Input Parameters

• mat - the matrix

• row - row permutation

• col - column permutation

• info - options for factorization, includes

          fill - expected fill as ratio of original fill.
          dtcol - pivot tolerance (0 no pivot, 1 full column pivoting)
                   Run with the option -info to determine an optimal value to use

Notes

Most users should employ the KSP interface for linear solvers instead of working directly with matrix algebra routines such as this. See, e.g., KSPCreate().

This changes the state of the matrix to a factored matrix; it cannot be used for example with MatSetValues() unless one first calls MatSetUnfactored().

This is really in-place only for dense matrices, the preferred approach is to use MatGetFactor(), MatLUFactorSymbolic(), and MatLUFactorNumeric() when not using KSP.

Developer Note

The Fortran interface is not autogenerated as the interface definition cannot be generated correctly [due to MatFactorInfo]

See Also

Matrices, Matrix Factorization, Mat, MatFactorType, MatLUFactorSymbolic(), MatLUFactorNumeric(), MatCholeskyFactor(), MatGetOrdering(), MatSetUnfactored(), MatFactorInfo, MatGetFactor()

Level

developer

Location

src/mat/interface/matrix.c

Examples

src/ksp/ksp/tutorials/ex74.c

Implementations

MatLUFactor_SeqAIJ() in src/mat/impls/aij/seq/aijfact.c
MatLUFactor_SeqBAIJ() in src/mat/impls/baij/seq/baijfact.c
MatLUFactor_SeqDense() in src/mat/impls/dense/seq/dense.c
MatLUFactor_Elemental() in src/mat/impls/elemental/matelem.cxx
MatLUFactor_ScaLAPACK() in src/mat/impls/scalapack/matscalapack.c
MatLUFactor_HT() in src/mat/impls/transpose/htransm.c
MatLUFactor_Transpose() in src/mat/impls/transpose/transm.c

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