Performs symbolic ILU factorization of a matrix. Uses levels of fill only, not drop tolerance. Use MatLUFactorNumeric() to complete the factorization.


#include "petscmat.h" 
PetscErrorCode  MatILUFactorSymbolic(Mat mat,IS row,IS col,MatFactorInfo *info,Mat *fact)
Collective on Mat

Input Parameters

mat - the matrix
row - row permutation
column - column permutation
info - structure containing
     levels - number of levels of fill.
     expected fill - as ratio of original fill.
     1 or 0 - indicating force fill on diagonal (improves robustness for matrices
missing diagonal entries)

Output Parameters

fact -new matrix that has been symbolically factored


See the users manual for additional information about choosing the fill factor for better efficiency.

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

See Also

MatLUFactorSymbolic(), MatLUFactorNumeric(), MatCholeskyFactor()
MatGetOrdering(), MatFactorInfo

Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages