Reference documentation for deal.II version 9.4.0

#include <deal.II/lac/trilinos_precondition.h>

## Public Member Functions

AdditionalData (const unsigned int ic_fill=0, const double ic_atol=0., const double ic_rtol=1., const unsigned int overlap=0)

## Public Attributes

unsigned int ic_fill

double ic_atol

double ic_rtol

unsigned int overlap

## Detailed Description

Standardized data struct to pipe additional parameters to the preconditioner. The Trilinos IC decomposition allows for some fill-in, so it actually is a threshold incomplete Cholesky factorization. The amount of fill-in, and hence, the amount of memory used by this preconditioner, is controlled by the parameter ic_fill, which specifies this as a double. When forming the preconditioner, for certain problems bad conditioning (or just bad luck) can cause the preconditioner to be very poorly conditioned. Hence it can help to add diagonal perturbations to the original matrix and form the preconditioner for this slightly better matrix. ic_atol is an absolute perturbation that is added to the diagonal before forming the prec, and ic_rtol is a scaling factor $$rtol \geq 1$$. The last parameter specifies the overlap of the partitions when the preconditioner runs in parallel.

Definition at line 876 of file trilinos_precondition.h.

The documentation for this struct was generated from the following files: