PCILUSetUseDropTolerance

The preconditioner will use an ILU based on a drop tolerance.

#include "petscpc.h"  
int PCILUSetUseDropTolerance(PC pc,PetscReal dt,PetscReal dtcol,int maxrowcount)

Collective on PC

	pc	- the preconditioner context
	dt	- the drop tolerance, try from 1.e-10 to .1
	dtcol	- tolerance for column pivot, good values [0.1 to 0.01]
	maxrowcount	- the max number of nonzeros allowed in a row, best value depends on the number of nonzeros in row of original matrix

-pc_ilu_use_drop_tolerance <dt,dtcol,maxrowcount> -Sets drop tolerance

This uses the iludt() code of Saad's SPARSKIT package

PC, levels, reordering, factorization, incomplete, ILU