Date: 2013-07-02T14:51:10+00:00

Actual source code: gladapt.c
petsc-3.4.2 2013-07-02

      2: #include <../src/ts/impls/implicit/gl/gl.h> /*I  "petscts.h" I*/

      4: static PetscFunctionList TSGLAdaptList;
      5: static PetscBool         TSGLAdaptPackageInitialized;
      6: static PetscBool         TSGLAdaptRegisterAllCalled;
      7: static PetscClassId      TSGLADAPT_CLASSID;

      9: struct _TSGLAdaptOps {
     10:   PetscErrorCode (*choose)(TSGLAdapt,PetscInt,const PetscInt[],const PetscReal[],const PetscReal[],PetscInt,PetscReal,PetscReal,PetscInt*,PetscReal*,PetscBool*);
     11:   PetscErrorCode (*destroy)(TSGLAdapt);
     12:   PetscErrorCode (*view)(TSGLAdapt,PetscViewer);
     13:   PetscErrorCode (*setfromoptions)(TSGLAdapt);
     14: };

     16: struct _p_TSGLAdapt {
     17:   PETSCHEADER(struct _TSGLAdaptOps);
     18:   void *data;
     19: };

     21: PETSC_EXTERN PetscErrorCode TSGLAdaptCreate_None(TSGLAdapt);
     22: PETSC_EXTERN PetscErrorCode TSGLAdaptCreate_Size(TSGLAdapt);
     23: PETSC_EXTERN PetscErrorCode TSGLAdaptCreate_Both(TSGLAdapt);

     27: /*@C
     28:    TSGLAdaptRegister -  adds a TSGLAdapt implementation

     30:    Not Collective

     32:    Input Parameters:
     33: +  name_scheme - name of user-defined adaptivity scheme
     34: -  routine_create - routine to create method context

     36:    Notes:
     37:    TSGLAdaptRegister() may be called multiple times to add several user-defined families.

     39:    Sample usage:
     40: .vb
     41:    TSGLAdaptRegister("my_scheme",MySchemeCreate);
     42: .ve

     44:    Then, your scheme can be chosen with the procedural interface via
     45: $     TSGLAdaptSetType(ts,"my_scheme")
     46:    or at runtime via the option
     47: $     -ts_adapt_type my_scheme

     49:    Level: advanced

     51: .keywords: TSGLAdapt, register

     53: .seealso: TSGLAdaptRegisterAll()
     54: @*/
     55: PetscErrorCode  TSGLAdaptRegister(const char sname[],PetscErrorCode (*function)(TSGLAdapt))
     56: {

     60:   PetscFunctionListAdd(&TSGLAdaptList,sname,function);
     61:   return(0);
     62: }

     66: /*@C
     67:   TSGLAdaptRegisterAll - Registers all of the adaptivity schemes in TSGLAdapt

     69:   Not Collective

     71:   Level: advanced

     73: .keywords: TSGLAdapt, register, all

     75: .seealso: TSGLAdaptRegisterDestroy()
     76: @*/
     77: PetscErrorCode  TSGLAdaptRegisterAll(void)
     78: {

     82:   TSGLAdaptRegister(TSGLADAPT_NONE,TSGLAdaptCreate_None);
     83:   TSGLAdaptRegister(TSGLADAPT_SIZE,TSGLAdaptCreate_Size);
     84:   TSGLAdaptRegister(TSGLADAPT_BOTH,TSGLAdaptCreate_Both);
     85:   return(0);
     86: }

     90: /*@C
     91:   TSGLFinalizePackage - This function destroys everything in the TSGL package. It is
     92:   called from PetscFinalize().

     94:   Level: developer

     96: .keywords: Petsc, destroy, package
     97: .seealso: PetscFinalize()
     98: @*/
     99: PetscErrorCode  TSGLAdaptFinalizePackage(void)
    100: {

    104:   PetscFunctionListDestroy(&TSGLAdaptList);
    105:   TSGLAdaptPackageInitialized = PETSC_FALSE;
    106:   TSGLAdaptRegisterAllCalled  = PETSC_FALSE;
    107:   return(0);
    108: }

    112: /*@C
    113:   TSGLAdaptInitializePackage - This function initializes everything in the TSGLAdapt package. It is
    114:   called from PetscDLLibraryRegister() when using dynamic libraries, and on the first call to
    115:   TSCreate_GL() when using static libraries.

    117:   Level: developer

    119: .keywords: TSGLAdapt, initialize, package
    120: .seealso: PetscInitialize()
    121: @*/
    122: PetscErrorCode  TSGLAdaptInitializePackage(void)
    123: {

    127:   if (TSGLAdaptPackageInitialized) return(0);
    128:   TSGLAdaptPackageInitialized = PETSC_TRUE;
    129:   PetscClassIdRegister("TSGLAdapt",&TSGLADAPT_CLASSID);
    130:   TSGLAdaptRegisterAll();
    131:   PetscRegisterFinalize(TSGLAdaptFinalizePackage);
    132:   return(0);
    133: }

    137: PetscErrorCode  TSGLAdaptSetType(TSGLAdapt adapt,TSGLAdaptType type)
    138: {
    139:   PetscErrorCode ierr,(*r)(TSGLAdapt);

    142:   PetscFunctionListFind(TSGLAdaptList,type,&r);
    143:   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unknown TSGLAdapt type \"%s\" given",type);
    144:   if (((PetscObject)adapt)->type_name) {(*adapt->ops->destroy)(adapt);}
    145:   (*r)(adapt);
    146:   PetscObjectChangeTypeName((PetscObject)adapt,type);
    147:   return(0);
    148: }

    152: PetscErrorCode  TSGLAdaptSetOptionsPrefix(TSGLAdapt adapt,const char prefix[])
    153: {

    157:   PetscObjectSetOptionsPrefix((PetscObject)adapt,prefix);
    158:   return(0);
    159: }

    163: PetscErrorCode  TSGLAdaptView(TSGLAdapt adapt,PetscViewer viewer)
    164: {
    166:   PetscBool      iascii;

    169:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
    170:   if (iascii) {
    171:     PetscObjectPrintClassNamePrefixType((PetscObject)adapt,viewer,"TSGLAdapt Object");
    172:     if (adapt->ops->view) {
    173:       PetscViewerASCIIPushTab(viewer);
    174:       (*adapt->ops->view)(adapt,viewer);
    175:       PetscViewerASCIIPopTab(viewer);
    176:     }
    177:   }
    178:   return(0);
    179: }

    183: PetscErrorCode  TSGLAdaptDestroy(TSGLAdapt *adapt)
    184: {

    188:   if (!*adapt) return(0);
    190:   if (--((PetscObject)(*adapt))->refct > 0) {*adapt = 0; return(0);}
    191:   if ((*adapt)->ops->destroy) {(*(*adapt)->ops->destroy)(*adapt);}
    192:   PetscHeaderDestroy(adapt);
    193:   return(0);
    194: }

    198: PetscErrorCode  TSGLAdaptSetFromOptions(TSGLAdapt adapt)
    199: {
    201:   char           type[256] = TSGLADAPT_BOTH;
    202:   PetscBool      flg;

    205:   /* This should use PetscOptionsBegin() if/when this becomes an object used outside of TSGL, but currently this
    206:   * function can only be called from inside TSSetFromOptions_GL()  */
    207:   PetscOptionsHead("TSGL Adaptivity options");
    208:   PetscOptionsList("-ts_adapt_type","Algorithm to use for adaptivity","TSGLAdaptSetType",TSGLAdaptList,
    209:                           ((PetscObject)adapt)->type_name ? ((PetscObject)adapt)->type_name : type,type,sizeof(type),&flg);
    210:   if (flg || !((PetscObject)adapt)->type_name) {
    211:     TSGLAdaptSetType(adapt,type);
    212:   }
    213:   if (adapt->ops->setfromoptions) {(*adapt->ops->setfromoptions)(adapt);}
    214:   PetscOptionsTail();
    215:   return(0);
    216: }

    220: PetscErrorCode  TSGLAdaptChoose(TSGLAdapt adapt,PetscInt n,const PetscInt orders[],const PetscReal errors[],const PetscReal cost[],PetscInt cur,PetscReal h,PetscReal tleft,PetscInt *next_sc,PetscReal *next_h,PetscBool  *finish)
    221: {

    232:   (*adapt->ops->choose)(adapt,n,orders,errors,cost,cur,h,tleft,next_sc,next_h,finish);
    233:   return(0);
    234: }

    238: PetscErrorCode  TSGLAdaptCreate(MPI_Comm comm,TSGLAdapt *inadapt)
    239: {
    241:   TSGLAdapt      adapt;

    244:   *inadapt = 0;
    245:   PetscHeaderCreate(adapt,_p_TSGLAdapt,struct _TSGLAdaptOps,TSGLADAPT_CLASSID,"TSGLAdapt","General Linear adaptivity","TS",comm,TSGLAdaptDestroy,TSGLAdaptView);
    246:   *inadapt = adapt;
    247:   return(0);
    248: }

    251: /*
    252: *  Implementations
    253: */

    257: static PetscErrorCode TSGLAdaptDestroy_JustFree(TSGLAdapt adapt)
    258: {

    262:   PetscFree(adapt->data);
    263:   return(0);
    264: }

    266: /* -------------------------------- None ----------------------------------- */
    267: typedef struct {
    268:   PetscInt  scheme;
    269:   PetscReal h;
    270: } TSGLAdapt_None;

    274: static PetscErrorCode TSGLAdaptChoose_None(TSGLAdapt adapt,PetscInt n,const PetscInt orders[],const PetscReal errors[],const PetscReal cost[],PetscInt cur,PetscReal h,PetscReal tleft,PetscInt *next_sc,PetscReal *next_h,PetscBool  *finish)
    275: {

    278:   *next_sc = cur;
    279:   *next_h  = h;
    280:   if (*next_h > tleft) {
    281:     *finish = PETSC_TRUE;
    282:     *next_h = tleft;
    283:   } else *finish = PETSC_FALSE;
    284:   return(0);
    285: }

    289: PetscErrorCode  TSGLAdaptCreate_None(TSGLAdapt adapt)
    290: {
    292:   TSGLAdapt_None *a;

    295:   PetscNewLog(adapt,TSGLAdapt_None,&a);
    296:   adapt->data         = (void*)a;
    297:   adapt->ops->choose  = TSGLAdaptChoose_None;
    298:   adapt->ops->destroy = TSGLAdaptDestroy_JustFree;
    299:   return(0);
    300: }

    302: /* -------------------------------- Size ----------------------------------- */
    303: typedef struct {
    304:   PetscReal desired_h;
    305: } TSGLAdapt_Size;

    310: static PetscErrorCode TSGLAdaptChoose_Size(TSGLAdapt adapt,PetscInt n,const PetscInt orders[],const PetscReal errors[],const PetscReal cost[],PetscInt cur,PetscReal h,PetscReal tleft,PetscInt *next_sc,PetscReal *next_h,PetscBool  *finish)
    311: {
    312:   TSGLAdapt_Size *sz = (TSGLAdapt_Size*)adapt->data;
    313:   PetscReal      dec = 0.2,inc = 5.0,safe = 0.9,optimal,last_desired_h;

    316:   *next_sc = cur;
    317:   optimal  = PetscPowReal((PetscReal)errors[cur],(PetscReal)-1./(safe*orders[cur]));
    318:   /* Step sizes oscillate when there is no smoothing.  Here we use a geometric mean of the the current step size and the
    319:   * one that would have been taken (without smoothing) on the last step. */
    320:   last_desired_h = sz->desired_h;
    321:   sz->desired_h  = h*PetscMax(dec,PetscMin(inc,optimal)); /* Trim to [dec,inc] */

    323:   /* Normally only happens on the first step */
    324:   if (last_desired_h > 1e-14) *next_h = PetscSqrtReal(last_desired_h * sz->desired_h);
    325:   else *next_h = sz->desired_h;

    327:   if (*next_h > tleft) {
    328:     *finish = PETSC_TRUE;
    329:     *next_h = tleft;
    330:   } else *finish = PETSC_FALSE;
    331:   return(0);
    332: }

    336: PetscErrorCode  TSGLAdaptCreate_Size(TSGLAdapt adapt)
    337: {
    339:   TSGLAdapt_Size *a;

    342:   PetscNewLog(adapt,TSGLAdapt_Size,&a);
    343:   adapt->data         = (void*)a;
    344:   adapt->ops->choose  = TSGLAdaptChoose_Size;
    345:   adapt->ops->destroy = TSGLAdaptDestroy_JustFree;
    346:   return(0);
    347: }

    349: /* -------------------------------- Both ----------------------------------- */
    350: typedef struct {
    351:   PetscInt  count_at_order;
    352:   PetscReal desired_h;
    353: } TSGLAdapt_Both;

    358: static PetscErrorCode TSGLAdaptChoose_Both(TSGLAdapt adapt,PetscInt n,const PetscInt orders[],const PetscReal errors[],const PetscReal cost[],PetscInt cur,PetscReal h,PetscReal tleft,PetscInt *next_sc,PetscReal *next_h,PetscBool  *finish)
    359: {
    360:   TSGLAdapt_Both *both = (TSGLAdapt_Both*)adapt->data;
    362:   PetscReal      dec = 0.2,inc = 5.0,safe = 0.9;
    363:   struct {PetscInt id; PetscReal h,eff;} best={-1,0,0},trial={-1,0,0},current={-1,0,0};
    364:   PetscInt i;

    367:   for (i=0; i<n; i++) {
    368:     PetscReal optimal;
    369:     trial.id  = i;
    370:     optimal   = PetscPowReal((PetscReal)errors[i],(PetscReal)-1./(safe*orders[i]));
    371:     trial.h   = h*optimal;
    372:     trial.eff = trial.h/cost[i];
    373:     if (trial.eff > best.eff) {PetscMemcpy(&best,&trial,sizeof(trial));}
    374:     if (i == cur) {PetscMemcpy(&current,&trial,sizeof(trial));}
    375:   }
    376:   /* Only switch orders if the scheme offers significant benefits over the current one.
    377:   When the scheme is not changing, only change step size if it offers significant benefits. */
    378:   if (best.eff < 1.2*current.eff || both->count_at_order < orders[cur]+2) {
    379:     PetscReal last_desired_h;
    380:     *next_sc        = current.id;
    381:     last_desired_h  = both->desired_h;
    382:     both->desired_h = PetscMax(h*dec,PetscMin(h*inc,current.h));
    383:     *next_h         = (both->count_at_order > 0)
    384:                       ? PetscSqrtReal(last_desired_h * both->desired_h)
    385:                       : both->desired_h;
    386:     both->count_at_order++;
    387:   } else {
    388:     PetscReal rat = cost[best.id]/cost[cur];
    389:     *next_sc = best.id;
    390:     *next_h  = PetscMax(h*rat*dec,PetscMin(h*rat*inc,best.h));
    391:     both->count_at_order = 0;
    392:     both->desired_h      = best.h;
    393:   }

    395:   if (*next_h > tleft) {
    396:     *finish = PETSC_TRUE;
    397:     *next_h = tleft;
    398:   } else *finish = PETSC_FALSE;
    399:   return(0);
    400: }

    404: PetscErrorCode TSGLAdaptCreate_Both(TSGLAdapt adapt)
    405: {
    407:   TSGLAdapt_Both *a;

    410:   PetscNewLog(adapt,TSGLAdapt_Both,&a);
    411:   adapt->data         = (void*)a;
    412:   adapt->ops->choose  = TSGLAdaptChoose_Both;
    413:   adapt->ops->destroy = TSGLAdaptDestroy_JustFree;
    414:   return(0);
    415: }