Specific auxiliaries

• Fill Strategy. Routine:

  
  Command: int AMLSetFillMethod(PC pc,AMLFillMethod fill_method)
  		Option:T-multilevel_fillmethod <method>      
  

  where the method parameter is one of the following:

  • No fill-in:

    
     		Argument:TAMLFillNone
    Option value: 		none      
    

  • Diagonal fill-in:

    
     		Argument:TAMLFillDiag
    Option value: 		diag      
    

  • Only fill-in large elements:

    
     		Argument:TAMLFillStrong
    Option value: 		strong      
    

    This is a drop tolerance method.

  • Accept the full matrix:

    
     		Argument:TAMLFillFull
    Option value: 		full      
    

    .

  See further section .
• Coarse Grid Choice. With

  
  Command: int AMLSetCoarseGridDependent(PC pc)
  		Option:T-multilevel_coarsegrid dependent      
  

  the coarse grid is taken as the complement of the independent set; with

  
  Command: int AMLSetCoarseGridIndependent(PC pc)
  		Option:T-multilevel_coarsegrid independent      
  

  the coarse grid is taken as the independent set itself. See further section .

• Solution Scheme. Routine:

  int AMLSetSolutionScheme(PC pc,AMLSolveScheme scheme)
  

  where the scheme parameter is one of the following:

  AMLSolveILU

  a straightforward Gaussian factorisation solve.

  AMLSolveMG

  same, but with pre and post smoother; see section .

  AMLSolvePolynomial

  a generalised W-cycle solver. Not implemented yet.

• Smoothers. See section .