Actual source code: pcmgimpl.h
petsc-3.12.4 2020-02-04
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      1: /*
      2:       Data structure used for Multigrid preconditioner.
      3: */
      6:  #include <petsc/private/pcimpl.h>
      7:  #include <petscksp.h>

      9: /*
     10:      Each level has its own copy of this data.
     11:      Level (0) is always the coarsest level and Level (levels-1) is the finest.
     12: */
     13: typedef struct {
     14:   PetscInt cycles;                             /* Type of cycle to run: 1 V 2 W */
     15:   PetscInt level;                              /* level = 0 coarsest level */
     16:   PetscInt levels;                             /* number of active levels used */
     17:   Vec      b;                                  /* Right hand side */
     18:   Vec      x;                                  /* Solution */
     19:   Vec      r;                                  /* Residual */

     21:   PetscErrorCode (*residual)(Mat,Vec,Vec,Vec);

     23:   Mat           A;                             /* matrix used in forming residual*/
     24:   KSP           smoothd;                       /* pre smoother */
     25:   KSP           smoothu;                       /* post smoother */
     26:   Mat           interpolate;
     27:   Mat           restrct;                       /* restrict is a reserved word in C99 and on Cray */
     28:   Mat           inject;                        /* Used for moving state if provided. */
     29:   Vec           rscale;                        /* scaling of restriction matrix */
     30:   PetscLogEvent eventsmoothsetup;              /* if logging times for each level */
     31:   PetscLogEvent eventsmoothsolve;
     32:   PetscLogEvent eventresidual;
     33:   PetscLogEvent eventinterprestrict;
     34: } PC_MG_Levels;

     36: /*
     37:     This data structure is shared by all the levels.
     38: */
     39: typedef struct {
     40:   PCMGType         am;                        /* Multiplicative, additive or full */
     41:   PetscInt         cyclesperpcapply;          /* Number of cycles to use in each PCApply(), multiplicative only*/
     42:   PetscInt         maxlevels;                 /* total number of levels allocated */
     43:   PCMGGalerkinType galerkin;                  /* use Galerkin process to compute coarser matrices */
     44:   PetscBool        usedmfornumberoflevels;    /* sets the number of levels by getting this information out of the DM */

     46:   PetscInt     nlevels;
     47:   PC_MG_Levels **levels;
     48:   PetscInt     default_smoothu;               /* number of smooths per level if not over-ridden */
     49:   PetscInt     default_smoothd;               /*  with calls to KSPSetTolerances() */
     50:   PetscReal    rtol,abstol,dtol,ttol;         /* tolerances for when running with PCApplyRichardson_MG */

     52:   void          *innerctx;                    /* optional data for preconditioner, like PCEXOTIC that inherits off of PCMG */
     53:   PetscLogStage stageApply;
     54:   PetscErrorCode (*view)(PC,PetscViewer);     /* GAMG and other objects that use PCMG can set their own viewer here */
     55: } PC_MG;

     57: PETSC_INTERN PetscErrorCode PCSetUp_MG(PC);
     58: PETSC_INTERN PetscErrorCode PCDestroy_MG(PC);
     59: PETSC_INTERN PetscErrorCode PCSetFromOptions_MG(PetscOptionItems *PetscOptionsObject,PC);
     60: PETSC_INTERN PetscErrorCode PCView_MG(PC,PetscViewer);
     61: PETSC_INTERN PetscErrorCode PCMGGetLevels_MG(PC,PetscInt *);
     62: PETSC_INTERN PetscErrorCode PCMGSetLevels_MG(PC,PetscInt,MPI_Comm *);
     63: PETSC_DEPRECATED_FUNCTION("Use PCMGResidualDefault() (since version 3.5)") PETSC_STATIC_INLINE PetscErrorCode PCMGResidual_Default(Mat A,Vec b,Vec x,Vec r) {
     64:   return PCMGResidualDefault(A,b,x,r);
     65: }

     67: #endif