libMesh

Callable abstract base class to be used as a callback to provide the solver with a basis for the system's Jacobian's nullspace (the kernel or the "zero energy modes") or nearnullspace (the "low energy modes"). More...
#include <nonlinear_implicit_system.h>
Public Member Functions  
virtual  ~ComputeVectorSubspace () 
virtual void  operator() (std::vector< NumericVector< Number > *> &sp, sys_type &s)=0 
This function will be called to compute the subspace basis (e.g., nullspace or nearnullspace). More...  
Callable abstract base class to be used as a callback to provide the solver with a basis for the system's Jacobian's nullspace (the kernel or the "zero energy modes") or nearnullspace (the "low energy modes").
A nullspace can be used to solve a degenerate problem iteratively (e.g., with a Krylov subspace method). A near nullspace can be used by an Algebraic Multigrid (AMG) preconditioner to construct smoothed aggregationlike coarse spaces.
Definition at line 147 of file nonlinear_implicit_system.h.

virtual 
Definition at line 150 of file nonlinear_implicit_system.h.

pure virtual 
This function will be called to compute the subspace basis (e.g., nullspace or nearnullspace).
It must be implemented by the user in a derived class.