xref: /petsc/src/ksp/pc/impls/factor/ilu/ilu.c (revision 967c93d3e64042876ac07e1b7cb9c7deaf12a7a1)
1dba47a55SKris Buschelman 
29b54502bSHong Zhang /*
39b54502bSHong Zhang    Defines a ILU factorization preconditioner for any Mat implementation
49b54502bSHong Zhang */
5c6db04a5SJed Brown #include <../src/ksp/pc/impls/factor/ilu/ilu.h>     /*I "petscpc.h"  I*/
69b54502bSHong Zhang 
79b54502bSHong Zhang /* ------------------------------------------------------------------------------------------*/
8afaefe49SHong Zhang #undef __FUNCT__
92401956bSBarry Smith #define __FUNCT__ "PCFactorSetReuseFill_ILU"
107087cfbeSBarry Smith PetscErrorCode  PCFactorSetReuseFill_ILU(PC pc,PetscBool flag)
112401956bSBarry Smith {
12075768bcSBarry Smith   PC_ILU *lu = (PC_ILU*)pc->data;
132401956bSBarry Smith 
142401956bSBarry Smith   PetscFunctionBegin;
152401956bSBarry Smith   lu->reusefill = flag;
162401956bSBarry Smith   PetscFunctionReturn(0);
172401956bSBarry Smith }
182401956bSBarry Smith 
192401956bSBarry Smith #undef __FUNCT__
202401956bSBarry Smith #define __FUNCT__ "PCFactorReorderForNonzeroDiagonal_ILU"
217087cfbeSBarry Smith PetscErrorCode  PCFactorReorderForNonzeroDiagonal_ILU(PC pc,PetscReal z)
229b54502bSHong Zhang {
239b54502bSHong Zhang   PC_ILU *ilu = (PC_ILU*)pc->data;
249b54502bSHong Zhang 
259b54502bSHong Zhang   PetscFunctionBegin;
269b54502bSHong Zhang   ilu->nonzerosalongdiagonal = PETSC_TRUE;
272fa5cd67SKarl Rupp   if (z == PETSC_DECIDE) ilu->nonzerosalongdiagonaltol = 1.e-10;
282fa5cd67SKarl Rupp   else ilu->nonzerosalongdiagonaltol = z;
299b54502bSHong Zhang   PetscFunctionReturn(0);
309b54502bSHong Zhang }
319b54502bSHong Zhang 
329b54502bSHong Zhang #undef __FUNCT__
33574deadeSBarry Smith #define __FUNCT__ "PCReset_ILU"
34574deadeSBarry Smith PetscErrorCode PCReset_ILU(PC pc)
359b54502bSHong Zhang {
369b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
379b54502bSHong Zhang   PetscErrorCode ierr;
389b54502bSHong Zhang 
399b54502bSHong Zhang   PetscFunctionBegin;
40298cc208SBarry Smith   if (!ilu->inplace) {ierr = MatDestroy(&((PC_Factor*)ilu)->fact);CHKERRQ(ierr);}
416bf464f9SBarry Smith   if (ilu->row && ilu->col && ilu->row != ilu->col) {ierr = ISDestroy(&ilu->row);CHKERRQ(ierr);}
42fcfd50ebSBarry Smith   ierr = ISDestroy(&ilu->col);CHKERRQ(ierr);
439b54502bSHong Zhang   PetscFunctionReturn(0);
449b54502bSHong Zhang }
459b54502bSHong Zhang 
469b54502bSHong Zhang #undef __FUNCT__
47b7c853c4SBarry Smith #define __FUNCT__ "PCFactorSetDropTolerance_ILU"
487087cfbeSBarry Smith PetscErrorCode  PCFactorSetDropTolerance_ILU(PC pc,PetscReal dt,PetscReal dtcol,PetscInt dtcount)
499b54502bSHong Zhang {
50075768bcSBarry Smith   PC_ILU *ilu = (PC_ILU*)pc->data;
519b54502bSHong Zhang 
529b54502bSHong Zhang   PetscFunctionBegin;
534c9036c7SBarry Smith   if (pc->setupcalled && (((PC_Factor*)ilu)->info.dt != dt || ((PC_Factor*)ilu)->info.dtcol != dtcol || ((PC_Factor*)ilu)->info.dtcount != dtcount)) {
54ce94432eSBarry Smith     SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Cannot change drop tolerance after using PC");
559b54502bSHong Zhang   }
56075768bcSBarry Smith   ((PC_Factor*)ilu)->info.dt      = dt;
57075768bcSBarry Smith   ((PC_Factor*)ilu)->info.dtcol   = dtcol;
58075768bcSBarry Smith   ((PC_Factor*)ilu)->info.dtcount = dtcount;
594c9036c7SBarry Smith   ((PC_Factor*)ilu)->info.usedt   = 1.0;
609b54502bSHong Zhang   PetscFunctionReturn(0);
619b54502bSHong Zhang }
629b54502bSHong Zhang 
639b54502bSHong Zhang #undef __FUNCT__
642401956bSBarry Smith #define __FUNCT__ "PCFactorSetReuseOrdering_ILU"
657087cfbeSBarry Smith PetscErrorCode  PCFactorSetReuseOrdering_ILU(PC pc,PetscBool flag)
669b54502bSHong Zhang {
67075768bcSBarry Smith   PC_ILU *ilu = (PC_ILU*)pc->data;
689b54502bSHong Zhang 
699b54502bSHong Zhang   PetscFunctionBegin;
709b54502bSHong Zhang   ilu->reuseordering = flag;
719b54502bSHong Zhang   PetscFunctionReturn(0);
729b54502bSHong Zhang }
739b54502bSHong Zhang 
749b54502bSHong Zhang #undef __FUNCT__
752401956bSBarry Smith #define __FUNCT__ "PCFactorSetUseInPlace_ILU"
768e37d05fSBarry Smith PetscErrorCode  PCFactorSetUseInPlace_ILU(PC pc,PetscBool flg)
779b54502bSHong Zhang {
78075768bcSBarry Smith   PC_ILU *dir = (PC_ILU*)pc->data;
799b54502bSHong Zhang 
809b54502bSHong Zhang   PetscFunctionBegin;
818e37d05fSBarry Smith   dir->inplace = flg;
828e37d05fSBarry Smith   PetscFunctionReturn(0);
838e37d05fSBarry Smith }
848e37d05fSBarry Smith 
858e37d05fSBarry Smith #undef __FUNCT__
868e37d05fSBarry Smith #define __FUNCT__ "PCFactorGetUseInPlace_ILU"
878e37d05fSBarry Smith PetscErrorCode  PCFactorGetUseInPlace_ILU(PC pc,PetscBool *flg)
888e37d05fSBarry Smith {
898e37d05fSBarry Smith   PC_ILU *dir = (PC_ILU*)pc->data;
908e37d05fSBarry Smith 
918e37d05fSBarry Smith   PetscFunctionBegin;
928e37d05fSBarry Smith   *flg = dir->inplace;
939b54502bSHong Zhang   PetscFunctionReturn(0);
949b54502bSHong Zhang }
959b54502bSHong Zhang 
969b54502bSHong Zhang #undef __FUNCT__
979b54502bSHong Zhang #define __FUNCT__ "PCSetFromOptions_ILU"
988c34d3f5SBarry Smith static PetscErrorCode PCSetFromOptions_ILU(PetscOptions *PetscOptionsObject,PC pc)
999b54502bSHong Zhang {
1009b54502bSHong Zhang   PetscErrorCode ierr;
10178fc6b22SHong Zhang   PetscInt       itmp;
1028afaa268SBarry Smith   PetscBool      flg,set;
1039b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
1049b54502bSHong Zhang   PetscReal      tol;
1059b54502bSHong Zhang 
1069b54502bSHong Zhang   PetscFunctionBegin;
107e55864a3SBarry Smith   ierr = PetscOptionsHead(PetscOptionsObject,"ILU Options");CHKERRQ(ierr);
108e55864a3SBarry Smith   ierr = PCSetFromOptions_Factor(PetscOptionsObject,pc);CHKERRQ(ierr);
1098ff23777SHong Zhang 
110075768bcSBarry Smith   ierr = PetscOptionsInt("-pc_factor_levels","levels of fill","PCFactorSetLevels",(PetscInt)((PC_Factor*)ilu)->info.levels,&itmp,&flg);CHKERRQ(ierr);
111075768bcSBarry Smith   if (flg) ((PC_Factor*)ilu)->info.levels = itmp;
1122fa5cd67SKarl Rupp 
1138afaa268SBarry Smith   ierr = PetscOptionsBool("-pc_factor_diagonal_fill","Allow fill into empty diagonal entry","PCFactorSetAllowDiagonalFill",((PC_Factor*)ilu)->info.diagonal_fill ? PETSC_TRUE : PETSC_FALSE,&flg,&set);CHKERRQ(ierr);
1148afaa268SBarry Smith   if (set) ((PC_Factor*)ilu)->info.diagonal_fill = (PetscReal) flg;
1152401956bSBarry Smith   ierr = PetscOptionsName("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",&flg);CHKERRQ(ierr);
1169b54502bSHong Zhang   if (flg) {
1179b54502bSHong Zhang     tol  = PETSC_DECIDE;
1182401956bSBarry Smith     ierr = PetscOptionsReal("-pc_factor_nonzeros_along_diagonal","Reorder to remove zeros from diagonal","PCFactorReorderForNonzeroDiagonal",ilu->nonzerosalongdiagonaltol,&tol,0);CHKERRQ(ierr);
1192401956bSBarry Smith     ierr = PCFactorReorderForNonzeroDiagonal(pc,tol);CHKERRQ(ierr);
1209b54502bSHong Zhang   }
1219b54502bSHong Zhang 
1229b54502bSHong Zhang   ierr = PetscOptionsTail();CHKERRQ(ierr);
1239b54502bSHong Zhang   PetscFunctionReturn(0);
1249b54502bSHong Zhang }
1259b54502bSHong Zhang 
1269b54502bSHong Zhang #undef __FUNCT__
1279b54502bSHong Zhang #define __FUNCT__ "PCView_ILU"
1289b54502bSHong Zhang static PetscErrorCode PCView_ILU(PC pc,PetscViewer viewer)
1299b54502bSHong Zhang {
1309b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
1319b54502bSHong Zhang   PetscErrorCode ierr;
132ace3abfcSBarry Smith   PetscBool      iascii;
1339b54502bSHong Zhang 
1349b54502bSHong Zhang   PetscFunctionBegin;
135251f4c67SDmitry Karpeev   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
1369b54502bSHong Zhang   if (iascii) {
137914a5d51SHong Zhang     if (ilu->inplace) {
138914a5d51SHong Zhang       ierr = PetscViewerASCIIPrintf(viewer,"  ILU: in-place factorization\n");CHKERRQ(ierr);
1399b54502bSHong Zhang     } else {
140914a5d51SHong Zhang       ierr = PetscViewerASCIIPrintf(viewer,"  ILU: out-of-place factorization\n");CHKERRQ(ierr);
141145b9266SHong Zhang     }
142145b9266SHong Zhang 
143914a5d51SHong Zhang     if (ilu->reusefill)     {ierr = PetscViewerASCIIPrintf(viewer,"  ILU: Reusing fill from past factorization\n");CHKERRQ(ierr);}
144914a5d51SHong Zhang     if (ilu->reuseordering) {ierr = PetscViewerASCIIPrintf(viewer,"  ILU: Reusing reordering from past factorization\n");CHKERRQ(ierr);}
1459b54502bSHong Zhang   }
146914a5d51SHong Zhang   ierr = PCView_Factor(pc,viewer);CHKERRQ(ierr);
1479b54502bSHong Zhang   PetscFunctionReturn(0);
1489b54502bSHong Zhang }
1499b54502bSHong Zhang 
1509b54502bSHong Zhang #undef __FUNCT__
1519b54502bSHong Zhang #define __FUNCT__ "PCSetUp_ILU"
1529b54502bSHong Zhang static PetscErrorCode PCSetUp_ILU(PC pc)
1539b54502bSHong Zhang {
1549b54502bSHong Zhang   PetscErrorCode ierr;
1559b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
156f3a39becSBarry Smith   MatInfo        info;
157ace3abfcSBarry Smith   PetscBool      flg;
1589b54502bSHong Zhang 
1599b54502bSHong Zhang   PetscFunctionBegin;
16092927226SBarry Smith   /* ugly hack to change default, since it is not support by some matrix types */
16192927226SBarry Smith   if (((PC_Factor*)ilu)->info.shifttype == (PetscReal)MAT_SHIFT_NONZERO) {
16222d28d08SBarry Smith     ierr = PetscObjectTypeCompare((PetscObject)pc->pmat,MATSEQAIJ,&flg);CHKERRQ(ierr);
16392927226SBarry Smith     if (!flg) {
16422d28d08SBarry Smith       ierr = PetscObjectTypeCompare((PetscObject)pc->pmat,MATMPIAIJ,&flg);CHKERRQ(ierr);
16592927226SBarry Smith       if (!flg) {
16692927226SBarry Smith         ((PC_Factor*)ilu)->info.shifttype = (PetscReal)MAT_SHIFT_INBLOCKS;
167955c1f14SBarry Smith         PetscInfo(pc,"Changing shift type from NONZERO to INBLOCKS because block matrices do not support NONZERO\n");CHKERRQ(ierr);
16892927226SBarry Smith       }
16992927226SBarry Smith     }
17092927226SBarry Smith   }
17192927226SBarry Smith 
1729b54502bSHong Zhang   if (ilu->inplace) {
1739b54502bSHong Zhang     if (!pc->setupcalled) {
1749b54502bSHong Zhang 
1759b54502bSHong Zhang       /* In-place factorization only makes sense with the natural ordering,
1769b54502bSHong Zhang          so we only need to get the ordering once, even if nonzero structure changes */
177075768bcSBarry Smith       ierr = MatGetOrdering(pc->pmat,((PC_Factor*)ilu)->ordering,&ilu->row,&ilu->col);CHKERRQ(ierr);
1783bb1ff40SBarry Smith       if (ilu->row) {ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilu->row);CHKERRQ(ierr);}
1793bb1ff40SBarry Smith       if (ilu->col) {ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilu->col);CHKERRQ(ierr);}
1809b54502bSHong Zhang     }
1819b54502bSHong Zhang 
1829b54502bSHong Zhang     /* In place ILU only makes sense with fill factor of 1.0 because
1839b54502bSHong Zhang        cannot have levels of fill */
184075768bcSBarry Smith     ((PC_Factor*)ilu)->info.fill          = 1.0;
18575567043SBarry Smith     ((PC_Factor*)ilu)->info.diagonal_fill = 0.0;
1862fa5cd67SKarl Rupp 
187365a8a9eSBarry Smith     ierr = MatILUFactor(pc->pmat,ilu->row,ilu->col,&((PC_Factor*)ilu)->info);CHKERRQ(ierr);CHKERRQ(ierr);
188075768bcSBarry Smith     ((PC_Factor*)ilu)->fact = pc->pmat;
189b33856dcSBarry Smith     /* must update the pc record of the matrix state or the PC will attempt to run PCSetUp() yet again */
190b33856dcSBarry Smith     ierr = PetscObjectStateGet((PetscObject)pc->pmat,&pc->matstate);CHKERRQ(ierr);
1919b54502bSHong Zhang   } else {
1929b54502bSHong Zhang     if (!pc->setupcalled) {
1939b54502bSHong Zhang       /* first time in so compute reordering and symbolic factorization */
194075768bcSBarry Smith       ierr = MatGetOrdering(pc->pmat,((PC_Factor*)ilu)->ordering,&ilu->row,&ilu->col);CHKERRQ(ierr);
1953bb1ff40SBarry Smith       if (ilu->row) {ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilu->row);CHKERRQ(ierr);}
1963bb1ff40SBarry Smith       if (ilu->col) {ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilu->col);CHKERRQ(ierr);}
1979b54502bSHong Zhang       /*  Remove zeros along diagonal?     */
1989b54502bSHong Zhang       if (ilu->nonzerosalongdiagonal) {
1999b54502bSHong Zhang         ierr = MatReorderForNonzeroDiagonal(pc->pmat,ilu->nonzerosalongdiagonaltol,ilu->row,ilu->col);CHKERRQ(ierr);
2009b54502bSHong Zhang       }
20186daa42cSBarry Smith       if (!((PC_Factor*)ilu)->fact) {
20211bfe483SHong Zhang         ierr = MatGetFactor(pc->pmat,((PC_Factor*)ilu)->solvertype,MAT_FACTOR_ILU,&((PC_Factor*)ilu)->fact);CHKERRQ(ierr);
203a1f19f5aSHong Zhang       }
204075768bcSBarry Smith       ierr = MatILUFactorSymbolic(((PC_Factor*)ilu)->fact,pc->pmat,ilu->row,ilu->col,&((PC_Factor*)ilu)->info);CHKERRQ(ierr);
205075768bcSBarry Smith       ierr = MatGetInfo(((PC_Factor*)ilu)->fact,MAT_LOCAL,&info);CHKERRQ(ierr);
2062fa5cd67SKarl Rupp 
207f3a39becSBarry Smith       ilu->actualfill = info.fill_ratio_needed;
2082fa5cd67SKarl Rupp 
2093bb1ff40SBarry Smith       ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)ilu)->fact);CHKERRQ(ierr);
2109b54502bSHong Zhang     } else if (pc->flag != SAME_NONZERO_PATTERN) {
2119b54502bSHong Zhang       if (!ilu->reuseordering) {
2129b54502bSHong Zhang         /* compute a new ordering for the ILU */
213fcfd50ebSBarry Smith         ierr = ISDestroy(&ilu->row);CHKERRQ(ierr);
214fcfd50ebSBarry Smith         ierr = ISDestroy(&ilu->col);CHKERRQ(ierr);
215075768bcSBarry Smith         ierr = MatGetOrdering(pc->pmat,((PC_Factor*)ilu)->ordering,&ilu->row,&ilu->col);CHKERRQ(ierr);
2163bb1ff40SBarry Smith         if (ilu->row) {ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilu->row);CHKERRQ(ierr);}
2173bb1ff40SBarry Smith         if (ilu->col) {ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)ilu->col);CHKERRQ(ierr);}
2189b54502bSHong Zhang         /*  Remove zeros along diagonal?     */
2199b54502bSHong Zhang         if (ilu->nonzerosalongdiagonal) {
2209b54502bSHong Zhang           ierr = MatReorderForNonzeroDiagonal(pc->pmat,ilu->nonzerosalongdiagonaltol,ilu->row,ilu->col);CHKERRQ(ierr);
2219b54502bSHong Zhang         }
2229b54502bSHong Zhang       }
2236bf464f9SBarry Smith       ierr = MatDestroy(&((PC_Factor*)ilu)->fact);CHKERRQ(ierr);
22414798fb4SJed Brown       ierr = MatGetFactor(pc->pmat,((PC_Factor*)ilu)->solvertype,MAT_FACTOR_ILU,&((PC_Factor*)ilu)->fact);CHKERRQ(ierr);
225075768bcSBarry Smith       ierr = MatILUFactorSymbolic(((PC_Factor*)ilu)->fact,pc->pmat,ilu->row,ilu->col,&((PC_Factor*)ilu)->info);CHKERRQ(ierr);
226075768bcSBarry Smith       ierr = MatGetInfo(((PC_Factor*)ilu)->fact,MAT_LOCAL,&info);CHKERRQ(ierr);
2272fa5cd67SKarl Rupp 
228f3a39becSBarry Smith       ilu->actualfill = info.fill_ratio_needed;
2292fa5cd67SKarl Rupp 
2303bb1ff40SBarry Smith       ierr = PetscLogObjectParent((PetscObject)pc,(PetscObject)((PC_Factor*)ilu)->fact);CHKERRQ(ierr);
2319b54502bSHong Zhang     }
232422a814eSBarry Smith     ierr = MatSetErrorIfFPE(pc->pmat,pc->erroriffailure);CHKERRQ(ierr);
233075768bcSBarry Smith     ierr = MatLUFactorNumeric(((PC_Factor*)ilu)->fact,pc->pmat,&((PC_Factor*)ilu)->info);CHKERRQ(ierr);
2349b54502bSHong Zhang   }
2359b54502bSHong Zhang   PetscFunctionReturn(0);
2369b54502bSHong Zhang }
2379b54502bSHong Zhang 
2389b54502bSHong Zhang #undef __FUNCT__
2399b54502bSHong Zhang #define __FUNCT__ "PCDestroy_ILU"
2409b54502bSHong Zhang static PetscErrorCode PCDestroy_ILU(PC pc)
2419b54502bSHong Zhang {
2429b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
2439b54502bSHong Zhang   PetscErrorCode ierr;
2449b54502bSHong Zhang 
2459b54502bSHong Zhang   PetscFunctionBegin;
246574deadeSBarry Smith   ierr = PCReset_ILU(pc);CHKERRQ(ierr);
247503cfb0cSBarry Smith   ierr = PetscFree(((PC_Factor*)ilu)->solvertype);CHKERRQ(ierr);
248503cfb0cSBarry Smith   ierr = PetscFree(((PC_Factor*)ilu)->ordering);CHKERRQ(ierr);
249c31cb41cSBarry Smith   ierr = PetscFree(pc->data);CHKERRQ(ierr);
2509b54502bSHong Zhang   PetscFunctionReturn(0);
2519b54502bSHong Zhang }
2529b54502bSHong Zhang 
2539b54502bSHong Zhang #undef __FUNCT__
2549b54502bSHong Zhang #define __FUNCT__ "PCApply_ILU"
2559b54502bSHong Zhang static PetscErrorCode PCApply_ILU(PC pc,Vec x,Vec y)
2569b54502bSHong Zhang {
2579b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
2589b54502bSHong Zhang   PetscErrorCode ierr;
2599b54502bSHong Zhang 
2609b54502bSHong Zhang   PetscFunctionBegin;
261075768bcSBarry Smith   ierr = MatSolve(((PC_Factor*)ilu)->fact,x,y);CHKERRQ(ierr);
2629b54502bSHong Zhang   PetscFunctionReturn(0);
2639b54502bSHong Zhang }
2649b54502bSHong Zhang 
2659b54502bSHong Zhang #undef __FUNCT__
2669b54502bSHong Zhang #define __FUNCT__ "PCApplyTranspose_ILU"
2679b54502bSHong Zhang static PetscErrorCode PCApplyTranspose_ILU(PC pc,Vec x,Vec y)
2689b54502bSHong Zhang {
2699b54502bSHong Zhang   PC_ILU         *ilu = (PC_ILU*)pc->data;
2709b54502bSHong Zhang   PetscErrorCode ierr;
2719b54502bSHong Zhang 
2729b54502bSHong Zhang   PetscFunctionBegin;
273075768bcSBarry Smith   ierr = MatSolveTranspose(((PC_Factor*)ilu)->fact,x,y);CHKERRQ(ierr);
2749b54502bSHong Zhang   PetscFunctionReturn(0);
2759b54502bSHong Zhang }
2769b54502bSHong Zhang 
277f0b9ad6cSBarry Smith #undef __FUNCT__
278f0b9ad6cSBarry Smith #define __FUNCT__ "PCApplySymmetricLeft_ILU"
279f0b9ad6cSBarry Smith static PetscErrorCode PCApplySymmetricLeft_ILU(PC pc,Vec x,Vec y)
280f0b9ad6cSBarry Smith {
281f0b9ad6cSBarry Smith   PetscErrorCode ierr;
282f0b9ad6cSBarry Smith   PC_ILU         *icc = (PC_ILU*)pc->data;
283f0b9ad6cSBarry Smith 
284f0b9ad6cSBarry Smith   PetscFunctionBegin;
285f0b9ad6cSBarry Smith   ierr = MatForwardSolve(((PC_Factor*)icc)->fact,x,y);CHKERRQ(ierr);
286f0b9ad6cSBarry Smith   PetscFunctionReturn(0);
287f0b9ad6cSBarry Smith }
288f0b9ad6cSBarry Smith 
289f0b9ad6cSBarry Smith #undef __FUNCT__
290f0b9ad6cSBarry Smith #define __FUNCT__ "PCApplySymmetricRight_ILU"
291f0b9ad6cSBarry Smith static PetscErrorCode PCApplySymmetricRight_ILU(PC pc,Vec x,Vec y)
292f0b9ad6cSBarry Smith {
293f0b9ad6cSBarry Smith   PetscErrorCode ierr;
294f0b9ad6cSBarry Smith   PC_ILU         *icc = (PC_ILU*)pc->data;
295f0b9ad6cSBarry Smith 
296f0b9ad6cSBarry Smith   PetscFunctionBegin;
297f0b9ad6cSBarry Smith   ierr = MatBackwardSolve(((PC_Factor*)icc)->fact,x,y);CHKERRQ(ierr);
298f0b9ad6cSBarry Smith   PetscFunctionReturn(0);
299f0b9ad6cSBarry Smith }
300f0b9ad6cSBarry Smith 
3019b54502bSHong Zhang /*MC
3029b54502bSHong Zhang      PCILU - Incomplete factorization preconditioners.
3039b54502bSHong Zhang 
3049b54502bSHong Zhang    Options Database Keys:
3052401956bSBarry Smith +  -pc_factor_levels <k> - number of levels of fill for ILU(k)
3062401956bSBarry Smith .  -pc_factor_in_place - only for ILU(0) with natural ordering, reuses the space of the matrix for
3079b54502bSHong Zhang                       its factorization (overwrites original matrix)
3082401956bSBarry Smith .  -pc_factor_diagonal_fill - fill in a zero diagonal even if levels of fill indicate it wouldn't be fill
3092401956bSBarry Smith .  -pc_factor_reuse_ordering - reuse ordering of factorized matrix from previous factorization
31055ba2a51SBarry Smith .  -pc_factor_fill <nfill> - expected amount of fill in factored matrix compared to original matrix, nfill > 1
3112401956bSBarry Smith .  -pc_factor_nonzeros_along_diagonal - reorder the matrix before factorization to remove zeros from the diagonal,
3129b54502bSHong Zhang                                    this decreases the chance of getting a zero pivot
3132401956bSBarry Smith .  -pc_factor_mat_ordering_type <natural,nd,1wd,rcm,qmd> - set the row/column ordering of the factored matrix
314*967c93d3SBarry Smith -  -pc_factor_pivot_in_blocks - for block ILU(k) factorization, i.e. with BAIJ matrices with block size larger
3159b54502bSHong Zhang                              than 1 the diagonal blocks are factored with partial pivoting (this increases the
3169b54502bSHong Zhang                              stability of the ILU factorization
3179b54502bSHong Zhang 
3189b54502bSHong Zhang    Level: beginner
3199b54502bSHong Zhang 
3209b54502bSHong Zhang   Concepts: incomplete factorization
3219b54502bSHong Zhang 
322d9ba8547SBarry Smith    Notes: Only implemented for some matrix formats. (for parallel see PCHYPRE for hypre's ILU)
3239b54502bSHong Zhang 
3249b54502bSHong Zhang           For BAIJ matrices this implements a point block ILU
3259b54502bSHong Zhang 
326f0b9ad6cSBarry Smith           The "symmetric" application of this preconditioner is not actually symmetric since L is not transpose(U)
327f0b9ad6cSBarry Smith           even when the matrix is not symmetric since the U stores the diagonals of the factorization.
328f0b9ad6cSBarry Smith 
329cd0a26f6SPaul Mullowney           If you are using MATSEQAIJCUSPARSE matrices (or MATMPIAIJCUSPARESE matrices with block Jacobi), factorization
330cd0a26f6SPaul Mullowney           is never done on the GPU).
331ac793be5SBarry Smith 
332c582cd25SBarry Smith    References:
333c582cd25SBarry Smith    T. Dupont, R. Kendall, and H. Rachford. An approximate factorization procedure for solving
334c582cd25SBarry Smith    self-adjoint elliptic difference equations. SIAM J. Numer. Anal., 5:559--573, 1968.
335c582cd25SBarry Smith 
336c582cd25SBarry Smith    T.A. Oliphant. An implicit numerical method for solving two-dimensional time-dependent dif-
337c582cd25SBarry Smith    fusion problems. Quart. Appl. Math., 19:221--229, 1961.
338c582cd25SBarry Smith 
339*967c93d3SBarry Smith    Review article:
340*967c93d3SBarry Smith     APPROXIMATE AND INCOMPLETE FACTORIZATIONS, TONY F. CHAN AND HENK A. VAN DER VORST
341c582cd25SBarry Smith       http://igitur-archive.library.uu.nl/math/2001-0621-115821/proc.pdf chapter in Parallel Numerical
342c582cd25SBarry Smith       Algorithms, edited by D. Keyes, A. Semah, V. Venkatakrishnan, ICASE/LaRC Interdisciplinary Series in
343c582cd25SBarry Smith       Science and Engineering, Kluwer, pp. 167--202.
344c582cd25SBarry Smith 
345c582cd25SBarry Smith 
3469b54502bSHong Zhang .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC, PCSOR, MatOrderingType,
347145b9266SHong Zhang            PCFactorSetZeroPivot(), PCFactorSetShiftSetType(), PCFactorSetAmount(),
348b7c853c4SBarry Smith            PCFactorSetDropTolerance(),PCFactorSetFill(), PCFactorSetMatOrderingType(), PCFactorSetReuseOrdering(),
34992e9c092SBarry Smith            PCFactorSetLevels(), PCFactorSetUseInPlace(), PCFactorSetAllowDiagonalFill(), PCFactorSetPivotInBlocks(),
35092e9c092SBarry Smith            PCFactorGetAllowDiagonalFill(), PCFactorGetUseInPlace()
3519b54502bSHong Zhang 
3529b54502bSHong Zhang M*/
3539b54502bSHong Zhang 
3549b54502bSHong Zhang #undef __FUNCT__
3559b54502bSHong Zhang #define __FUNCT__ "PCCreate_ILU"
3568cc058d9SJed Brown PETSC_EXTERN PetscErrorCode PCCreate_ILU(PC pc)
3579b54502bSHong Zhang {
3589b54502bSHong Zhang   PetscErrorCode ierr;
3599b54502bSHong Zhang   PC_ILU         *ilu;
3609b54502bSHong Zhang 
3619b54502bSHong Zhang   PetscFunctionBegin;
362b00a9115SJed Brown   ierr = PetscNewLog(pc,&ilu);CHKERRQ(ierr);
3639b54502bSHong Zhang 
364075768bcSBarry Smith   ((PC_Factor*)ilu)->fact               = 0;
365075768bcSBarry Smith   ierr                                  = MatFactorInfoInitialize(&((PC_Factor*)ilu)->info);CHKERRQ(ierr);
366879e8a4dSBarry Smith   ((PC_Factor*)ilu)->factortype         = MAT_FACTOR_ILU;
36775567043SBarry Smith   ((PC_Factor*)ilu)->info.levels        = 0.;
368075768bcSBarry Smith   ((PC_Factor*)ilu)->info.fill          = 1.0;
3699b54502bSHong Zhang   ilu->col                              = 0;
3709b54502bSHong Zhang   ilu->row                              = 0;
3719b54502bSHong Zhang   ilu->inplace                          = PETSC_FALSE;
3722692d6eeSBarry Smith   ierr                                  = PetscStrallocpy(MATSOLVERPETSC,&((PC_Factor*)ilu)->solvertype);CHKERRQ(ierr);
37319fd82e9SBarry Smith   ierr                                  = PetscStrallocpy(MATORDERINGNATURAL,(char**)&((PC_Factor*)ilu)->ordering);CHKERRQ(ierr);
3749b54502bSHong Zhang   ilu->reuseordering                    = PETSC_FALSE;
375075768bcSBarry Smith   ((PC_Factor*)ilu)->info.dt            = PETSC_DEFAULT;
376075768bcSBarry Smith   ((PC_Factor*)ilu)->info.dtcount       = PETSC_DEFAULT;
377075768bcSBarry Smith   ((PC_Factor*)ilu)->info.dtcol         = PETSC_DEFAULT;
378c378d667SBarry Smith   ((PC_Factor*)ilu)->info.shifttype     = (PetscReal)MAT_SHIFT_NONE;
3790ed735ceSHong Zhang   ((PC_Factor*)ilu)->info.shiftamount   = 100.0*PETSC_MACHINE_EPSILON;
3800ed735ceSHong Zhang   ((PC_Factor*)ilu)->info.zeropivot     = 100.0*PETSC_MACHINE_EPSILON;
381075768bcSBarry Smith   ((PC_Factor*)ilu)->info.pivotinblocks = 1.0;
3829b54502bSHong Zhang   ilu->reusefill                        = PETSC_FALSE;
3830ed735ceSHong Zhang   ((PC_Factor*)ilu)->info.diagonal_fill = 0.0;
3849b54502bSHong Zhang   pc->data                              = (void*)ilu;
3859b54502bSHong Zhang 
386574deadeSBarry Smith   pc->ops->reset               = PCReset_ILU;
3879b54502bSHong Zhang   pc->ops->destroy             = PCDestroy_ILU;
3889b54502bSHong Zhang   pc->ops->apply               = PCApply_ILU;
3899b54502bSHong Zhang   pc->ops->applytranspose      = PCApplyTranspose_ILU;
3909b54502bSHong Zhang   pc->ops->setup               = PCSetUp_ILU;
3919b54502bSHong Zhang   pc->ops->setfromoptions      = PCSetFromOptions_ILU;
39285317021SBarry Smith   pc->ops->getfactoredmatrix   = PCFactorGetMatrix_Factor;
3939b54502bSHong Zhang   pc->ops->view                = PCView_ILU;
394f0b9ad6cSBarry Smith   pc->ops->applysymmetricleft  = PCApplySymmetricLeft_ILU;
395f0b9ad6cSBarry Smith   pc->ops->applysymmetricright = PCApplySymmetricRight_ILU;
3969b54502bSHong Zhang   pc->ops->applyrichardson     = 0;
3979b54502bSHong Zhang 
398bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetZeroPivot_C",PCFactorSetZeroPivot_Factor);CHKERRQ(ierr);
399bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftType_C",PCFactorSetShiftType_Factor);CHKERRQ(ierr);
400bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetShiftAmount_C",PCFactorSetShiftAmount_Factor);CHKERRQ(ierr);
401bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetMatSolverPackage_C",PCFactorGetMatSolverPackage_Factor);CHKERRQ(ierr);
402bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatSolverPackage_C",PCFactorSetMatSolverPackage_Factor);CHKERRQ(ierr);
403bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUpMatSolverPackage_C",PCFactorSetUpMatSolverPackage_Factor);CHKERRQ(ierr);
404bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetDropTolerance_C",PCFactorSetDropTolerance_ILU);CHKERRQ(ierr);
405bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetFill_C",PCFactorSetFill_Factor);CHKERRQ(ierr);
406bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetMatOrderingType_C",PCFactorSetMatOrderingType_Factor);CHKERRQ(ierr);
407bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetReuseOrdering_C",PCFactorSetReuseOrdering_ILU);CHKERRQ(ierr);
408bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetReuseFill_C",PCFactorSetReuseFill_ILU);CHKERRQ(ierr);
409bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetLevels_C",PCFactorSetLevels_Factor);CHKERRQ(ierr);
4102591b318SToby Isaac   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetLevels_C",PCFactorGetLevels_Factor);CHKERRQ(ierr);
411bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetUseInPlace_C",PCFactorSetUseInPlace_ILU);CHKERRQ(ierr);
4128e37d05fSBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetUseInPlace_C",PCFactorGetUseInPlace_ILU);CHKERRQ(ierr);
413bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetAllowDiagonalFill_C",PCFactorSetAllowDiagonalFill_Factor);CHKERRQ(ierr);
41492e9c092SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetAllowDiagonalFill_C",PCFactorGetAllowDiagonalFill_Factor);CHKERRQ(ierr);
415bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorSetPivotInBlocks_C",PCFactorSetPivotInBlocks_Factor);CHKERRQ(ierr);
416bdf89e91SBarry Smith   ierr = PetscObjectComposeFunction((PetscObject)pc,"PCFactorReorderForNonzeroDiagonal_C",PCFactorReorderForNonzeroDiagonal_ILU);CHKERRQ(ierr);
4179b54502bSHong Zhang   PetscFunctionReturn(0);
4189b54502bSHong Zhang }
419