Actual source code: icc.c
petsc-3.10.5 2019-03-28
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      2:  #include <../src/ksp/pc/impls/factor/icc/icc.h>

      4: static PetscErrorCode PCSetUp_ICC(PC pc)
      5: {
      6:   PC_ICC                 *icc = (PC_ICC*)pc->data;
      7:   IS                     perm,cperm;
      8:   PetscErrorCode         ierr;
      9:   MatInfo                info;
     10:   MatSolverType          stype;
     11:   MatFactorError         err;

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

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

     31:   ISDestroy(&cperm);
     32:   ISDestroy(&perm);

     34:   MatFactorGetError(((PC_Factor*)icc)->fact,&err);
     35:   if (err) { /* FactorSymbolic() fails */
     36:     pc->failedreason = (PCFailedReason)err;
     37:     return(0);
     38:   }
     39:
     40:   MatCholeskyFactorNumeric(((PC_Factor*)icc)->fact,pc->pmat,&((PC_Factor*)icc)->info);
     41:   MatFactorGetError(((PC_Factor*)icc)->fact,&err);
     42:   if (err) { /* FactorNumeric() fails */
     43:     pc->failedreason = (PCFailedReason)err;
     44:   }

     46:   PCFactorGetMatSolverType(pc,&stype);
     47:   if (!stype) {
     48:     MatSolverType solverpackage;
     49:     MatFactorGetSolverType(((PC_Factor*)icc)->fact,&solverpackage);
     50:     PCFactorSetMatSolverType(pc,solverpackage);
     51:   }
     52:   return(0);
     53: }

     55: static PetscErrorCode PCReset_ICC(PC pc)
     56: {
     57:   PC_ICC         *icc = (PC_ICC*)pc->data;

     61:   MatDestroy(&((PC_Factor*)icc)->fact);
     62:   return(0);
     63: }

     65: static PetscErrorCode PCDestroy_ICC(PC pc)
     66: {
     67:   PC_ICC         *icc = (PC_ICC*)pc->data;

     71:   PCReset_ICC(pc);
     72:   PetscFree(((PC_Factor*)icc)->ordering);
     73:   PetscFree(((PC_Factor*)icc)->solvertype);
     74:   PetscFree(pc->data);
     75:   return(0);
     76: }

     78: static PetscErrorCode PCApply_ICC(PC pc,Vec x,Vec y)
     79: {
     80:   PC_ICC         *icc = (PC_ICC*)pc->data;

     84:   MatSolve(((PC_Factor*)icc)->fact,x,y);
     85:   return(0);
     86: }

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

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

     98: static PetscErrorCode PCApplySymmetricRight_ICC(PC pc,Vec x,Vec y)
     99: {
    101:   PC_ICC         *icc = (PC_ICC*)pc->data;

    104:   MatBackwardSolve(((PC_Factor*)icc)->fact,x,y);
    105:   return(0);
    106: }

    108: static PetscErrorCode PCSetFromOptions_ICC(PetscOptionItems *PetscOptionsObject,PC pc)
    109: {
    110:   PC_ICC         *icc = (PC_ICC*)pc->data;
    111:   PetscBool      flg;
    113:   /* PetscReal      dt[3];*/

    116:   PetscOptionsHead(PetscOptionsObject,"ICC Options");
    117:   PCSetFromOptions_Factor(PetscOptionsObject,pc);

    119:   PetscOptionsReal("-pc_factor_levels","levels of fill","PCFactorSetLevels",((PC_Factor*)icc)->info.levels,&((PC_Factor*)icc)->info.levels,&flg);
    120:   /*dt[0] = ((PC_Factor*)icc)->info.dt;
    121:   dt[1] = ((PC_Factor*)icc)->info.dtcol;
    122:   dt[2] = ((PC_Factor*)icc)->info.dtcount;
    123:   PetscInt       dtmax = 3;
    124:   PetscOptionsRealArray("-pc_factor_drop_tolerance","<dt,dtcol,maxrowcount>","PCFactorSetDropTolerance",dt,&dtmax,&flg);
    125:   if (flg) {
    126:     PCFactorSetDropTolerance(pc,dt[0],dt[1],(PetscInt)dt[2]);
    127:   }
    128:   */
    129:   PetscOptionsTail();
    130:   return(0);
    131: }

    133: static PetscErrorCode PCView_ICC(PC pc,PetscViewer viewer)
    134: {

    138:   PCView_Factor(pc,viewer);
    139:   return(0);
    140: }

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

    144: /*MC
    145:      PCICC - Incomplete Cholesky factorization preconditioners.

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

    154:    Level: beginner

    156:   Concepts: incomplete Cholesky factorization

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

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

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

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

    168:    References:
    169: .  1. - TONY F. CHAN AND HENK A. VAN DER VORST, Review article: APPROXIMATE AND INCOMPLETE FACTORIZATIONS,
    170:       Chapter in Parallel Numerical Algorithms, edited by D. Keyes, A. Semah, V. Venkatakrishnan, ICASE/LaRC Interdisciplinary Series in
    171:       Science and Engineering, Kluwer.

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

    179: M*/

    181: PETSC_EXTERN PetscErrorCode PCCreate_ICC(PC pc)
    182: {
    184:   PC_ICC         *icc;

    187:   PetscNewLog(pc,&icc);
    188:   pc->data = (void*)icc;
    189:   PCFactorInitialize(pc);
    190:   PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)icc)->ordering);

    192:   ((PC_Factor*)icc)->factortype     = MAT_FACTOR_ICC;
    193:   ((PC_Factor*)icc)->info.fill      = 1.0;
    194:   ((PC_Factor*)icc)->info.dtcol     = PETSC_DEFAULT;
    195:   ((PC_Factor*)icc)->info.shifttype = (PetscReal) MAT_SHIFT_POSITIVE_DEFINITE;

    197:   pc->ops->apply               = PCApply_ICC;
    198:   pc->ops->applytranspose      = PCApply_ICC;
    199:   pc->ops->setup               = PCSetUp_ICC;
    200:   pc->ops->reset               = PCReset_ICC;
    201:   pc->ops->destroy             = PCDestroy_ICC;
    202:   pc->ops->setfromoptions      = PCSetFromOptions_ICC;
    203:   pc->ops->view                = PCView_ICC;
    204:   pc->ops->applysymmetricleft  = PCApplySymmetricLeft_ICC;
    205:   pc->ops->applysymmetricright = PCApplySymmetricRight_ICC;
    206:   return(0);
    207: }