Date: 2015-10-02T22:19:02+00:00

Actual source code: icc.c
petsc-3.6.2 2015-10-02
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      2: #include <../src/ksp/pc/impls/factor/icc/icc.h>   /*I "petscpc.h" I*/

      6: static PetscErrorCode PCSetup_ICC(PC pc)
      7: {
      8:   PC_ICC         *icc = (PC_ICC*)pc->data;
      9:   IS             perm,cperm;
     11:   MatInfo        info;

     14:   MatGetOrdering(pc->pmat, ((PC_Factor*)icc)->ordering,&perm,&cperm);

     16:   if (!pc->setupcalled) {
     17:     if (!((PC_Factor*)icc)->fact) {
     18:       MatGetFactor(pc->pmat,((PC_Factor*)icc)->solvertype,MAT_FACTOR_ICC,&((PC_Factor*)icc)->fact);
     19:     }
     20:     MatICCFactorSymbolic(((PC_Factor*)icc)->fact,pc->pmat,perm,&((PC_Factor*)icc)->info);
     21:   } else if (pc->flag != SAME_NONZERO_PATTERN) {
     22:     MatDestroy(&((PC_Factor*)icc)->fact);
     23:     MatGetFactor(pc->pmat,((PC_Factor*)icc)->solvertype,MAT_FACTOR_ICC,&((PC_Factor*)icc)->fact);
     24:     MatICCFactorSymbolic(((PC_Factor*)icc)->fact,pc->pmat,perm,&((PC_Factor*)icc)->info);
     25:   }
     26:   MatGetInfo(((PC_Factor*)icc)->fact,MAT_LOCAL,&info);
     27:   icc->actualfill = info.fill_ratio_needed;

     29:   ISDestroy(&cperm);
     30:   ISDestroy(&perm);
     31:   MatCholeskyFactorNumeric(((PC_Factor*)icc)->fact,pc->pmat,&((PC_Factor*)icc)->info);
     32:   return(0);
     33: }

     37: static PetscErrorCode PCReset_ICC(PC pc)
     38: {
     39:   PC_ICC         *icc = (PC_ICC*)pc->data;

     43:   MatDestroy(&((PC_Factor*)icc)->fact);
     44:   return(0);
     45: }

     49: static PetscErrorCode PCDestroy_ICC(PC pc)
     50: {
     51:   PC_ICC         *icc = (PC_ICC*)pc->data;

     55:   PCReset_ICC(pc);
     56:   PetscFree(((PC_Factor*)icc)->ordering);
     57:   PetscFree(((PC_Factor*)icc)->solvertype);
     58:   PetscFree(pc->data);
     59:   return(0);
     60: }

     64: static PetscErrorCode PCApply_ICC(PC pc,Vec x,Vec y)
     65: {
     66:   PC_ICC         *icc = (PC_ICC*)pc->data;

     70:   MatSolve(((PC_Factor*)icc)->fact,x,y);
     71:   return(0);
     72: }

     76: static PetscErrorCode PCApplySymmetricLeft_ICC(PC pc,Vec x,Vec y)
     77: {
     79:   PC_ICC         *icc = (PC_ICC*)pc->data;

     82:   MatForwardSolve(((PC_Factor*)icc)->fact,x,y);
     83:   return(0);
     84: }

     88: static PetscErrorCode PCApplySymmetricRight_ICC(PC pc,Vec x,Vec y)
     89: {
     91:   PC_ICC         *icc = (PC_ICC*)pc->data;

     94:   MatBackwardSolve(((PC_Factor*)icc)->fact,x,y);
     95:   return(0);
     96: }

    100: static PetscErrorCode PCSetFromOptions_ICC(PetscOptions *PetscOptionsObject,PC pc)
    101: {
    102:   PC_ICC         *icc = (PC_ICC*)pc->data;
    103:   PetscBool      flg;
    105:   /* PetscReal      dt[3];*/

    108:   PetscOptionsHead(PetscOptionsObject,"ICC Options");
    109:   PCSetFromOptions_Factor(PetscOptionsObject,pc);

    111:   PetscOptionsReal("-pc_factor_levels","levels of fill","PCFactorSetLevels",((PC_Factor*)icc)->info.levels,&((PC_Factor*)icc)->info.levels,&flg);
    112:   /*dt[0] = ((PC_Factor*)icc)->info.dt;
    113:   dt[1] = ((PC_Factor*)icc)->info.dtcol;
    114:   dt[2] = ((PC_Factor*)icc)->info.dtcount;
    115:   PetscInt       dtmax = 3;
    116:   PetscOptionsRealArray("-pc_factor_drop_tolerance","<dt,dtcol,maxrowcount>","PCFactorSetDropTolerance",dt,&dtmax,&flg);
    117:   if (flg) {
    118:     PCFactorSetDropTolerance(pc,dt[0],dt[1],(PetscInt)dt[2]);
    119:   }
    120:   */
    121:   PetscOptionsTail();
    122:   return(0);
    123: }

    127: static PetscErrorCode PCView_ICC(PC pc,PetscViewer viewer)
    128: {

    132:   PCView_Factor(pc,viewer);
    133:   return(0);
    134: }

    136: extern PetscErrorCode  PCFactorSetDropTolerance_ILU(PC,PetscReal,PetscReal,PetscInt);

    140: PetscErrorCode  PCFactorGetUseInPlace_ICC(PC pc,PetscBool *flg)
    141: {
    143:   *flg = PETSC_FALSE;
    144:   return(0);
    145: }

    147: /*MC
    148:      PCICC - Incomplete Cholesky factorization preconditioners.

    150:    Options Database Keys:
    151: +  -pc_factor_levels <k> - number of levels of fill for ICC(k)
    152: .  -pc_factor_in_place - only for ICC(0) with natural ordering, reuses the space of the matrix for
    153:                       its factorization (overwrites original matrix)
    154: .  -pc_factor_fill <nfill> - expected amount of fill in factored matrix compared to original matrix, nfill > 1
    155: -  -pc_factor_mat_ordering_type <natural,nd,1wd,rcm,qmd> - set the row/column ordering of the factored matrix

    157:    Level: beginner

    159:   Concepts: incomplete Cholesky factorization

    161:    Notes: Only implemented for some matrix formats. Not implemented in parallel.

    163:           For BAIJ matrices this implements a point block ICC.

    165:           The Manteuffel shift is only implemented for matrices with block size 1

    167:           By default, the Manteuffel is applied (for matrices with block size 1). Call PCFactorSetShiftType(pc,MAT_SHIFT_POSITIVE_DEFINITE);
    168:           to turn off the shift.

    170:    References:
    171:    Review article: APPROXIMATE AND INCOMPLETE FACTORIZATIONS, TONY F. CHAN AND HENK A. VAN DER VORST
    172:       http://igitur-archive.library.uu.nl/math/2001-0621-115821/proc.pdf chapter in Parallel Numerical
    173:       Algorithms, edited by D. Keyes, A. Semah, V. Venkatakrishnan, ICASE/LaRC Interdisciplinary Series in
    174:       Science and Engineering, Kluwer, pp. 167--202.

    177: .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC, PCSOR, MatOrderingType,
    178:            PCFactorSetZeroPivot(), PCFactorSetShiftType(), PCFactorSetShiftAmount(),
    179:            PCFactorSetFill(), PCFactorSetMatOrderingType(), PCFactorSetReuseOrdering(),
    180:            PCFactorSetLevels()

    182: M*/

    186: PETSC_EXTERN PetscErrorCode PCCreate_ICC(PC pc)
    187: {
    189:   PC_ICC         *icc;

    192:   PetscNewLog(pc,&icc);

    194:   ((PC_Factor*)icc)->fact = 0;

    196:   PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)icc)->ordering);
    197:   PetscStrallocpy(MATSOLVERPETSC,&((PC_Factor*)icc)->solvertype);
    198:   MatFactorInfoInitialize(&((PC_Factor*)icc)->info);

    200:   ((PC_Factor*)icc)->factortype  = MAT_FACTOR_ICC;
    201:   ((PC_Factor*)icc)->info.levels = 0.;
    202:   ((PC_Factor*)icc)->info.fill   = 1.0;
    203:   icc->implctx                   = 0;

    205:   ((PC_Factor*)icc)->info.dtcol       = PETSC_DEFAULT;
    206:   ((PC_Factor*)icc)->info.shifttype   = (PetscReal) MAT_SHIFT_POSITIVE_DEFINITE;
    207:   ((PC_Factor*)icc)->info.shiftamount = 100.0*PETSC_MACHINE_EPSILON;
    208:   ((PC_Factor*)icc)->info.zeropivot   = 100.0*PETSC_MACHINE_EPSILON;

    210:   pc->data                     = (void*)icc;
    211:   pc->ops->apply               = PCApply_ICC;
    212:   pc->ops->applytranspose      = PCApply_ICC;
    213:   pc->ops->setup               = PCSetup_ICC;
    214:   pc->ops->reset               = PCReset_ICC;
    215:   pc->ops->destroy             = PCDestroy_ICC;
    216:   pc->ops->setfromoptions      = PCSetFromOptions_ICC;
    217:   pc->ops->view                = PCView_ICC;
    218:   pc->ops->getfactoredmatrix   = PCFactorGetMatrix_Factor;
    219:   pc->ops->applysymmetricleft  = PCApplySymmetricLeft_ICC;
    220:   pc->ops->applysymmetricright = PCApplySymmetricRight_ICC;

    222:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUpMatSolverPackage_C",PCFactorSetUpMatSolverPackage_Factor);
    223:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetMatSolverPackage_C",PCFactorGetMatSolverPackage_Factor);
    224:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetZeroPivot_C",PCFactorSetZeroPivot_Factor);
    225:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftType_C",PCFactorSetShiftType_Factor);
    226:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftAmount_C",PCFactorSetShiftAmount_Factor);
    227:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetLevels_C",PCFactorSetLevels_Factor);
    228:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetLevels_C",PCFactorGetLevels_Factor);
    229:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetFill_C",PCFactorSetFill_Factor);
    230:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatOrderingType_C",PCFactorSetMatOrderingType_Factor);
    231:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatSolverPackage_C",PCFactorSetMatSolverPackage_Factor);
    232:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetDropTolerance_C",PCFactorSetDropTolerance_ILU);
    233:   PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetUseInPlace_C",PCFactorGetUseInPlace_ICC);
    234:   return(0);
    235: }