Actual source code: evsl.c

slepc-3.17.1 2022-04-11
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    This file implements a wrapper to eigensolvers in EVSL.
 12: */

 14: #include <slepc/private/epsimpl.h>
 15: #include <evsl.h>

 17: #define PetscCallEVSL(func, ...) do {                                                   \
 18:     PetscStackPush(PetscStringize(func));                                                      \
 19:     PetscErrorCode evsl_ierr_ = func(__VA_ARGS__);                                              \
 20:     PetscStackPop;                                                                             \
 22:   } while (0)

 24: typedef struct {
 25:   PetscBool         initialized;
 26:   Mat               A;           /* problem matrix */
 27:   Vec               x,y;         /* auxiliary vectors */
 28:   PetscReal         *sli;        /* slice bounds */
 29:   PetscInt          nev;         /* approximate number of wanted eigenvalues in each slice */
 30:   PetscLayout       map;         /* used to distribute slices among MPI processes */
 31:   PetscBool         estimrange;  /* the filter range was not set by the user */
 32:   /* user parameters */
 33:   PetscInt          nslices;     /* number of slices */
 34:   PetscReal         lmin,lmax;   /* numerical range (min and max eigenvalue) */
 35:   EPSEVSLDOSMethod  dos;         /* DOS method, either KPM or Lanczos */
 36:   PetscInt          nvec;        /* number of sample vectors used for DOS */
 37:   PetscInt          deg;         /* polynomial degree used for DOS (KPM only) */
 38:   PetscInt          steps;       /* number of Lanczos steps used for DOS (Lanczos only) */
 39:   PetscInt          npoints;     /* number of sample points used for DOS (Lanczos only) */
 40:   PetscInt          max_deg;     /* maximum degree allowed for the polynomial */
 41:   PetscReal         thresh;      /* threshold for accepting polynomial */
 42:   EPSEVSLDamping    damping;     /* type of damping (for polynomial and for DOS-KPM) */
 43: } EPS_EVSL;

 45: static void AMatvec_EVSL(double *xa,double *ya,void *data)
 46: {
 47:   EPS_EVSL       *ctx = (EPS_EVSL*)data;
 48:   Vec            x = ctx->x,y = ctx->y;
 49:   Mat            A = ctx->A;

 51:   PetscObjectComm((PetscObject)A),VecPlaceArray(x,(PetscScalar*)xa);
 52:   PetscObjectComm((PetscObject)A),VecPlaceArray(y,(PetscScalar*)ya);
 53:   PetscObjectComm((PetscObject)A),MatMult(A,x,y);
 54:   PetscObjectComm((PetscObject)A),VecResetArray(x);
 55:   PetscObjectComm((PetscObject)A),VecResetArray(y);
 56:   return;
 57: }

 59: PetscErrorCode EPSSetUp_EVSL(EPS eps)
 60: {
 61:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;
 62:   PetscMPIInt    size,rank;
 63:   PetscBool      isshift;
 64:   PetscScalar    *vinit;
 65:   PetscReal      *mu,ecount,xintv[4],*xdos,*ydos;
 66:   Vec            v0;
 67:   Mat            A;
 68:   PetscRandom    rnd;

 70:   EPSCheckStandard(eps);
 71:   EPSCheckHermitian(eps);
 72:   PetscObjectTypeCompare((PetscObject)eps->st,STSHIFT,&isshift);

 75:   if (ctx->initialized) EVSLFinish();
 76:   EVSLStart();
 77:   ctx->initialized=PETSC_TRUE;

 79:   /* get number of slices per process */
 80:   MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);
 81:   MPI_Comm_rank(PetscObjectComm((PetscObject)eps),&rank);
 82:   if (!ctx->nslices) ctx->nslices = size;
 83:   PetscLayoutDestroy(&ctx->map);
 84:   PetscLayoutCreateFromSizes(PetscObjectComm((PetscObject)eps),PETSC_DECIDE,ctx->nslices,1,&ctx->map);

 86:   /* get matrix and prepare auxiliary vectors */
 87:   MatDestroy(&ctx->A);
 88:   STGetMatrix(eps->st,0,&A);
 89:   if (size==1) {
 90:     PetscObjectReference((PetscObject)A);
 91:     ctx->A = A;
 92:   } else {
 93:     MatCreateRedundantMatrix(A,0,PETSC_COMM_SELF,MAT_INITIAL_MATRIX,&ctx->A);
 94:     PetscLogObjectParent((PetscObject)eps,(PetscObject)ctx->A);
 95:   }
 96:   SetAMatvec(eps->n,&AMatvec_EVSL,(void*)ctx);
 97:   if (!ctx->x) {
 98:     MatCreateVecsEmpty(ctx->A,&ctx->x,&ctx->y);
 99:     PetscLogObjectParent((PetscObject)eps,(PetscObject)ctx->x);
100:     PetscLogObjectParent((PetscObject)eps,(PetscObject)ctx->y);
101:   }
102:   EPSCheckUnsupported(eps,EPS_FEATURE_ARBITRARY | EPS_FEATURE_REGION | EPS_FEATURE_STOPPING);
103:   EPSCheckIgnored(eps,EPS_FEATURE_EXTRACTION | EPS_FEATURE_CONVERGENCE);

105:   if (!eps->which) eps->which=EPS_ALL;

108:   /* estimate numerical range */
109:   if (ctx->estimrange || ctx->lmin == PETSC_MIN_REAL || ctx->lmax == PETSC_MAX_REAL) {
110:     MatCreateVecs(ctx->A,&v0,NULL);
111:     if (!eps->V) EPSGetBV(eps,&eps->V);
112:     BVGetRandomContext(eps->V,&rnd);
113:     VecSetRandom(v0,rnd);
114:     VecGetArray(v0,&vinit);
115:     LanTrbounds,50,200,eps->tol,vinit,1,&ctx->lmin,&ctx->lmax,NULL;
116:     VecRestoreArray(v0,&vinit);
117:     VecDestroy(&v0);
118:     ctx->estimrange = PETSC_TRUE;   /* estimate if called again with another matrix */
119:   }
121:   xintv[0] = eps->inta;
122:   xintv[1] = eps->intb;
123:   xintv[2] = ctx->lmin;
124:   xintv[3] = ctx->lmax;

126:   /* estimate number of eigenvalues in the interval */
127:   switch (ctx->dos) {
128:     case EPS_EVSL_DOS_KPM:
129:       PetscMalloc1(ctx->deg+1,&mu);
130:       if (!rank) kpmdos,ctx->deg,(int)ctx->damping,ctx->nvec,xintv,mu,&ecount;
131:       MPI_Bcast(mu,ctx->deg+1,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));
132:       break;
133:     case EPS_EVSL_DOS_LANCZOS:
134:       PetscMalloc2(ctx->npoints,&xdos,ctx->npoints,&ydos);
135:       if (!rank) LanDos,ctx->nvec,PetscMin(ctx->steps,eps->n/2),ctx->npoints,xdos,ydos,&ecount,xintv;
136:       MPI_Bcast(xdos,ctx->npoints,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));
137:       MPI_Bcast(ydos,ctx->npoints,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));
138:       break;
139:     default:
140:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid DOS method");
141:   }
142:   MPI_Bcast(&ecount,1,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));

144:   PetscInfo(eps,"Estimated eigenvalue count in the interval: %g\n",ecount);
145:   eps->ncv = (PetscInt)PetscCeilReal(1.5*ecount);

147:   /* slice the spectrum */
148:   PetscFree(ctx->sli);
149:   PetscMalloc1(ctx->nslices+1,&ctx->sli);
150:   if (ctx->dos == EPS_EVSL_DOS_KPM) {
151:     spslicer,ctx->sli,mu,ctx->deg,xintv,ctx->nslices,10*(PetscInt)ecount;
152:     PetscFree(mu);
153:   } else if (ctx->dos == EPS_EVSL_DOS_LANCZOS) {
154:     spslicer2(xdos,ydos,ctx->nslices,ctx->npoints,ctx->sli);
155:     PetscFree2(xdos,ydos);
156:   }

158:   /* approximate number of eigenvalues wanted in each slice */
159:   ctx->nev = (PetscInt)(1.0 + ecount/(PetscReal)ctx->nslices) + 2;

161:   if (eps->mpd!=PETSC_DEFAULT) PetscInfo(eps,"Warning: parameter mpd ignored\n");
162:   if (eps->max_it==PETSC_DEFAULT) eps->max_it = 1;
163:   EPSAllocateSolution(eps,0);
164:   PetscFunctionReturn(0);
165: }

167: PetscErrorCode EPSSolve_EVSL(EPS eps)
168: {
169:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;
170:   PetscInt       i,j,k=0,sl,mlan,nevout,*ind,nevmax,rstart,rend,*nevloc,*disp,N;
171:   PetscReal      *res,xintv[4],*errest;
172:   PetscScalar    *lam,*X,*Y,*vinit,*eigr;
173:   PetscMPIInt    size,rank;
174:   PetscRandom    rnd;
175:   Vec            v,w,v0,x;
176:   VecScatter     vs;
177:   IS             is;
178:   polparams      pol;

180:   MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);
181:   MPI_Comm_rank(PetscObjectComm((PetscObject)eps),&rank);
182:   PetscLayoutGetRange(ctx->map,&rstart,&rend);
183:   nevmax = (rend-rstart)*ctx->nev;
184:   MatCreateVecs(ctx->A,&v0,NULL);
185:   BVGetRandomContext(eps->V,&rnd);
186:   VecSetRandom(v0,rnd);
187:   VecGetArray(v0,&vinit);
188:   PetscMalloc5(size,&nevloc,size+1,&disp,nevmax,&eigr,nevmax,&errest,nevmax*eps->n,&X);
189:   mlan = PetscMin(PetscMax(5*ctx->nev,300),eps->n);
190:   for (sl=rstart; sl<rend; sl++) {
191:     xintv[0] = ctx->sli[sl];
192:     xintv[1] = ctx->sli[sl+1];
193:     xintv[2] = ctx->lmin;
194:     xintv[3] = ctx->lmax;
195:     PetscInfo(ctx->A,"Subinterval %" PetscInt_FMT ": [%.4e, %.4e]\n",sl+1,xintv[0],xintv[1]);
196:     set_pol_def(&pol);
197:     pol.max_deg    = ctx->max_deg;
198:     pol.damping    = (int)ctx->damping;
199:     pol.thresh_int = ctx->thresh;
200:     find_pol(xintv,&pol);
201:     PetscInfo(ctx->A,"Polynomial [type = %" PetscInt_FMT "], deg %" PetscInt_FMT ", bar %e gam %e\n",pol.type,pol.deg,pol.bar,pol.gam);
202:     ChebLanNr,xintv,mlan,eps->tol,vinit,&pol,&nevout,&lam,&Y,&res,NULL;
204:     free_pol(&pol);
205:     PetscInfo(ctx->A,"Computed %" PetscInt_FMT " eigenvalues\n",nevout);
206:     PetscMalloc1(nevout,&ind);
207:     sort_double(nevout,lam,ind);
208:     for (i=0;i<nevout;i++) {
209:       eigr[i+k]   = lam[i];
210:       errest[i+k] = res[ind[i]];
211:       PetscArraycpy(X+(i+k)*eps->n,Y+ind[i]*eps->n,eps->n);
212:     }
213:     k += nevout;
214:     if (lam) evsl_Free(lam);
215:     if (Y)   evsl_Free_device(Y);
216:     if (res) evsl_Free(res);
217:     PetscFree(ind);
218:   }
219:   VecRestoreArray(v0,&vinit);
220:   VecDestroy(&v0);

222:   /* gather eigenvalues computed by each MPI process */
223:   MPI_Allgather(&k,1,MPIU_INT,nevloc,1,MPIU_INT,PetscObjectComm((PetscObject)eps));
224:   eps->nev = nevloc[0];
225:   disp[0]  = 0;
226:   for (i=1;i<size;i++) {
227:     eps->nev += nevloc[i];
228:     disp[i]   = disp[i-1]+nevloc[i-1];
229:   }
230:   disp[size] = disp[size-1]+nevloc[size-1];
232:   MPI_Allgatherv(eigr,k,MPIU_SCALAR,eps->eigr,nevloc,disp,MPIU_SCALAR,PetscObjectComm((PetscObject)eps));
233:   MPI_Allgatherv(errest,k,MPIU_REAL,eps->errest,nevloc,disp,MPIU_REAL,PetscObjectComm((PetscObject)eps));
234:   eps->nconv  = eps->nev;
235:   eps->its    = 1;
236:   eps->reason = EPS_CONVERGED_TOL;

238:   /* scatter computed eigenvectors and store them in eps->V */
239:   BVCreateVec(eps->V,&w);
240:   for (i=0;i<size;i++) {
241:     N = (rank==i)? eps->n: 0;
242:     VecCreateSeq(PETSC_COMM_SELF,N,&x);
243:     VecSetFromOptions(x);
244:     ISCreateStride(PETSC_COMM_SELF,N,0,1,&is);
245:     VecScatterCreate(x,is,w,is,&vs);
246:     ISDestroy(&is);
247:     for (j=disp[i];j<disp[i+1];j++) {
248:       BVGetColumn(eps->V,j,&v);
249:       if (rank==i) VecPlaceArray(x,X+(j-disp[i])*eps->n);
250:       VecScatterBegin(vs,x,v,INSERT_VALUES,SCATTER_FORWARD);
251:       VecScatterEnd(vs,x,v,INSERT_VALUES,SCATTER_FORWARD);
252:       if (rank==i) VecResetArray(x);
253:       BVRestoreColumn(eps->V,j,&v);
254:     }
255:     VecScatterDestroy(&vs);
256:     VecDestroy(&x);
257:   }
258:   VecDestroy(&w);
259:   PetscFree5(nevloc,disp,eigr,errest,X);
260:   PetscFunctionReturn(0);
261: }

263: static PetscErrorCode EPSEVSLSetSlices_EVSL(EPS eps,PetscInt nslices)
264: {
265:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

267:   if (nslices == PETSC_DECIDE || nslices == PETSC_DEFAULT) nslices = 0;
269:   if (ctx->nslices != nslices) {
270:     ctx->nslices = nslices;
271:     eps->state   = EPS_STATE_INITIAL;
272:   }
273:   PetscFunctionReturn(0);
274: }

276: /*@
277:    EPSEVSLSetSlices - Set the number of slices in which the interval must be
278:    subdivided.

280:    Logically Collective on eps

282:    Input Parameters:
283: +  eps     - the eigensolver context
284: -  nslices - the number of slices

286:    Options Database Key:
287: .  -eps_evsl_slices <n> - set the number of slices to n

289:    Notes:
290:    By default, one slice per MPI process is used. Depending on the number of
291:    eigenvalues, using more slices may be beneficial, but very narrow subintervals
292:    imply higher polynomial degree.

294:    Level: intermediate

296: .seealso: EPSEVSLGetSlices()
297: @*/
298: PetscErrorCode EPSEVSLSetSlices(EPS eps,PetscInt nslices)
299: {
302:   PetscTryMethod(eps,"EPSEVSLSetSlices_C",(EPS,PetscInt),(eps,nslices));
303:   PetscFunctionReturn(0);
304: }

306: static PetscErrorCode EPSEVSLGetSlices_EVSL(EPS eps,PetscInt *nslices)
307: {
308:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

310:   *nslices = ctx->nslices;
311:   PetscFunctionReturn(0);
312: }

314: /*@
315:    EPSEVSLGetSlices - Gets the number of slices in which the interval must be
316:    subdivided.

318:    Not Collective

320:    Input Parameter:
321: .  eps - the eigensolver context

323:    Output Parameter:
324: .  nslices - the number of slices

326:    Level: intermediate

328: .seealso: EPSEVSLSetSlices()
329: @*/
330: PetscErrorCode EPSEVSLGetSlices(EPS eps,PetscInt *nslices)
331: {
334:   PetscUseMethod(eps,"EPSEVSLGetSlices_C",(EPS,PetscInt*),(eps,nslices));
335:   PetscFunctionReturn(0);
336: }

338: static PetscErrorCode EPSEVSLSetRange_EVSL(EPS eps,PetscReal lmin,PetscReal lmax)
339: {
340:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

343:   if (ctx->lmin != lmin || ctx->lmax != lmax) {
344:     ctx->lmin  = lmin;
345:     ctx->lmax  = lmax;
346:     eps->state = EPS_STATE_INITIAL;
347:   }
348:   PetscFunctionReturn(0);
349: }

351: /*@
352:    EPSEVSLSetRange - Defines the numerical range (or field of values) of the problem,
353:    that is, the interval containing all eigenvalues.

355:    Logically Collective on eps

357:    Input Parameters:
358: +  eps  - the eigensolver context
359: .  lmin - left end of the interval
360: -  lmax - right end of the interval

362:    Options Database Key:
363: .  -eps_evsl_range <a,b> - set [a,b] as the numerical range

365:    Notes:
366:    The filter will be most effective if the numerical range is tight, that is, lmin
367:    and lmax are good approximations to the leftmost and rightmost eigenvalues,
368:    respectively. If not set by the user, an approximation is computed internally.

370:    The wanted computational interval specified via EPSSetInterval() must be
371:    contained in the numerical range.

373:    Level: intermediate

375: .seealso: EPSEVSLGetRange(), EPSSetInterval()
376: @*/
377: PetscErrorCode EPSEVSLSetRange(EPS eps,PetscReal lmin,PetscReal lmax)
378: {
382:   PetscTryMethod(eps,"EPSEVSLSetRange_C",(EPS,PetscReal,PetscReal),(eps,lmin,lmax));
383:   PetscFunctionReturn(0);
384: }

386: static PetscErrorCode EPSEVSLGetRange_EVSL(EPS eps,PetscReal *lmin,PetscReal *lmax)
387: {
388:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

390:   if (lmin) *lmin = ctx->lmin;
391:   if (lmax) *lmax = ctx->lmax;
392:   PetscFunctionReturn(0);
393: }

395: /*@
396:    EPSEVSLGetRange - Gets the interval containing all eigenvalues.

398:    Not Collective

400:    Input Parameter:
401: .  eps - the eigensolver context

403:    Output Parameters:
404: +  lmin - left end of the interval
405: -  lmax - right end of the interval

407:    Level: intermediate

409: .seealso: EPSEVSLSetRange()
410: @*/
411: PetscErrorCode EPSEVSLGetRange(EPS eps,PetscReal *lmin,PetscReal *lmax)
412: {
414:   PetscUseMethod(eps,"EPSEVSLGetRange_C",(EPS,PetscReal*,PetscReal*),(eps,lmin,lmax));
415:   PetscFunctionReturn(0);
416: }

418: static PetscErrorCode EPSEVSLSetDOSParameters_EVSL(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)
419: {
420:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

422:   ctx->dos = dos;
423:   if (nvec == PETSC_DECIDE || nvec == PETSC_DEFAULT) ctx->nvec = 80;
425:   else ctx->nvec = nvec;
426:   switch (dos) {
427:     case EPS_EVSL_DOS_KPM:
428:       if (deg == PETSC_DECIDE || deg == PETSC_DEFAULT) ctx->deg = 300;
430:       else ctx->deg = deg;
431:       break;
432:     case EPS_EVSL_DOS_LANCZOS:
433:       if (steps == PETSC_DECIDE || steps == PETSC_DEFAULT) ctx->steps = 40;
435:       else ctx->steps = steps;
436:       if (npoints == PETSC_DECIDE || npoints == PETSC_DEFAULT) ctx->npoints = 200;
438:       else ctx->npoints = npoints;
439:       break;
440:   }
441:   eps->state = EPS_STATE_INITIAL;
442:   PetscFunctionReturn(0);
443: }

445: /*@
446:    EPSEVSLSetDOSParameters - Defines the parameters used for computing the
447:    density of states (DOS) in the EVSL solver.

449:    Logically Collective on eps

451:    Input Parameters:
452: +  eps     - the eigensolver context
453: .  dos     - DOS method, either KPM or Lanczos
454: .  nvec    - number of sample vectors
455: .  deg     - polynomial degree (KPM only)
456: .  steps   - number of Lanczos steps (Lanczos only)
457: -  npoints - number of sample points (Lanczos only)

459:    Options Database Keys:
460: +  -eps_evsl_dos_method <dos> - set the DOS method, either kpm or lanczos
461: .  -eps_evsl_dos_nvec <n> - set the number of sample vectors
462: .  -eps_evsl_dos_degree <n> - set the polynomial degree
463: .  -eps_evsl_dos_steps <n> - set the number of Lanczos steps
464: -  -eps_evsl_dos_npoints <n> - set the number of sample points

466:    Notes:
467:    The density of states (or spectral density) can be approximated with two
468:    methods, kernel polynomial method (KPM) or Lanczos. Some parameters for
469:    these methods can be set by the user with this function, with some of
470:    them being relevant for one of the methods only.

472:    Level: intermediate

474: .seealso: EPSEVSLGetDOSParameters()
475: @*/
476: PetscErrorCode EPSEVSLSetDOSParameters(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)
477: {
484:   PetscTryMethod(eps,"EPSEVSLSetDOSParameters_C",(EPS,EPSEVSLDOSMethod,PetscInt,PetscInt,PetscInt,PetscInt),(eps,dos,nvec,deg,steps,npoints));
485:   PetscFunctionReturn(0);
486: }

488: static PetscErrorCode EPSEVSLGetDOSParameters_EVSL(EPS eps,EPSEVSLDOSMethod *dos,PetscInt *nvec,PetscInt *deg,PetscInt *steps,PetscInt *npoints)
489: {
490:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

492:   if (dos)     *dos     = ctx->dos;
493:   if (nvec)    *nvec    = ctx->nvec;
494:   if (deg)     *deg     = ctx->deg;
495:   if (steps)   *steps   = ctx->steps;
496:   if (npoints) *npoints = ctx->npoints;
497:   PetscFunctionReturn(0);
498: }

500: /*@
501:    EPSEVSLGetDOSParameters - Gets the parameters used for computing the
502:    density of states (DOS) in the EVSL solver.

504:    Not Collective

506:    Input Parameter:
507: .  eps - the eigensolver context

509:    Output Parameters:
510: +  dos     - DOS method, either KPM or Lanczos
511: .  nvec    - number of sample vectors
512: .  deg     - polynomial degree (KPM only)
513: .  steps   - number of Lanczos steps (Lanczos only)
514: -  npoints - number of sample points (Lanczos only)

516:    Level: intermediate

518: .seealso: EPSEVSLSetDOSParameters()
519: @*/
520: PetscErrorCode EPSEVSLGetDOSParameters(EPS eps,EPSEVSLDOSMethod *dos,PetscInt *nvec,PetscInt *deg,PetscInt *steps,PetscInt *npoints)
521: {
523:   PetscUseMethod(eps,"EPSEVSLGetDOSParameters_C",(EPS,EPSEVSLDOSMethod*,PetscInt*,PetscInt*,PetscInt*,PetscInt*),(eps,dos,nvec,deg,steps,npoints));
524:   PetscFunctionReturn(0);
525: }

527: static PetscErrorCode EPSEVSLSetPolParameters_EVSL(EPS eps,PetscInt max_deg,PetscReal thresh)
528: {
529:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

531:   if (max_deg == PETSC_DECIDE || max_deg == PETSC_DEFAULT) ctx->max_deg = 10000;
533:   else ctx->max_deg = max_deg;
534:   if (thresh == PETSC_DECIDE || thresh == PETSC_DEFAULT) ctx->thresh = 0.8;
536:   else ctx->thresh = thresh;
537:   eps->state = EPS_STATE_INITIAL;
538:   PetscFunctionReturn(0);
539: }

541: /*@
542:    EPSEVSLSetPolParameters - Defines the parameters used for building the
543:    building the polynomial in the EVSL solver.

545:    Logically Collective on eps

547:    Input Parameters:
548: +  eps     - the eigensolver context
549: .  max_deg - maximum degree allowed for the polynomial
550: -  thresh  - threshold for accepting polynomial

552:    Options Database Keys:
553: +  -eps_evsl_pol_max_deg <d> - set maximum polynomial degree
554: -  -eps_evsl_pol_thresh <t> - set the threshold

556:    Level: intermediate

558: .seealso: EPSEVSLGetPolParameters()
559: @*/
560: PetscErrorCode EPSEVSLSetPolParameters(EPS eps,PetscInt max_deg,PetscReal thresh)
561: {
565:   PetscTryMethod(eps,"EPSEVSLSetPolParameters_C",(EPS,PetscInt,PetscReal),(eps,max_deg,thresh));
566:   PetscFunctionReturn(0);
567: }

569: static PetscErrorCode EPSEVSLGetPolParameters_EVSL(EPS eps,PetscInt *max_deg,PetscReal *thresh)
570: {
571:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

573:   if (max_deg) *max_deg = ctx->max_deg;
574:   if (thresh)  *thresh  = ctx->thresh;
575:   PetscFunctionReturn(0);
576: }

578: /*@
579:    EPSEVSLGetPolParameters - Gets the parameters used for building the
580:    polynomial in the EVSL solver.

582:    Not Collective

584:    Input Parameter:
585: .  eps - the eigensolver context

587:    Output Parameters:
588: +  max_deg - the maximum degree of the polynomial
589: -  thresh  - the threshold

591:    Level: intermediate

593: .seealso: EPSEVSLSetPolParameters()
594: @*/
595: PetscErrorCode EPSEVSLGetPolParameters(EPS eps,PetscInt *max_deg,PetscReal *thresh)
596: {
598:   PetscUseMethod(eps,"EPSEVSLGetPolParameters_C",(EPS,PetscInt*,PetscReal*),(eps,max_deg,thresh));
599:   PetscFunctionReturn(0);
600: }

602: static PetscErrorCode EPSEVSLSetDamping_EVSL(EPS eps,EPSEVSLDamping damping)
603: {
604:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

606:   if (ctx->damping != damping) {
607:     ctx->damping = damping;
608:     eps->state   = EPS_STATE_INITIAL;
609:   }
610:   PetscFunctionReturn(0);
611: }

613: /*@
614:    EPSEVSLSetDamping - Set the type of damping to be used in EVSL.

616:    Logically Collective on eps

618:    Input Parameters:
619: +  eps     - the eigensolver context
620: -  damping - the type of damping

622:    Options Database Key:
623: .  -eps_evsl_damping <n> - set the type of damping

625:    Notes:
626:    Damping is applied when building the polynomial to be used when solving the
627:    eigenproblem, and also during estimation of DOS with the KPM method.

629:    Level: intermediate

631: .seealso: EPSEVSLGetDamping(), EPSEVSLSetDOSParameters()
632: @*/
633: PetscErrorCode EPSEVSLSetDamping(EPS eps,EPSEVSLDamping damping)
634: {
637:   PetscTryMethod(eps,"EPSEVSLSetDamping_C",(EPS,EPSEVSLDamping),(eps,damping));
638:   PetscFunctionReturn(0);
639: }

641: static PetscErrorCode EPSEVSLGetDamping_EVSL(EPS eps,EPSEVSLDamping *damping)
642: {
643:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

645:   *damping = ctx->damping;
646:   PetscFunctionReturn(0);
647: }

649: /*@
650:    EPSEVSLGetDamping - Gets the type of damping.

652:    Not Collective

654:    Input Parameter:
655: .  eps - the eigensolver context

657:    Output Parameter:
658: .  damping - the type of damping

660:    Level: intermediate

662: .seealso: EPSEVSLSetDamping()
663: @*/
664: PetscErrorCode EPSEVSLGetDamping(EPS eps,EPSEVSLDamping *damping)
665: {
668:   PetscUseMethod(eps,"EPSEVSLGetDamping_C",(EPS,EPSEVSLDamping*),(eps,damping));
669:   PetscFunctionReturn(0);
670: }

672: PetscErrorCode EPSView_EVSL(EPS eps,PetscViewer viewer)
673: {
674:   PetscBool      isascii;
675:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

677:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
678:   if (isascii) {
679:     PetscViewerASCIIPrintf(viewer,"  numerical range = [%g,%g]\n",(double)ctx->lmin,(double)ctx->lmax);
680:     PetscViewerASCIIPrintf(viewer,"  number of slices = %" PetscInt_FMT "\n",ctx->nslices);
681:     PetscViewerASCIIPrintf(viewer,"  type of damping = %s\n",EPSEVSLDampings[ctx->damping]);
682:     PetscViewerASCIIPrintf(viewer,"  computing DOS with %s: nvec=%" PetscInt_FMT ", ",EPSEVSLDOSMethods[ctx->dos],ctx->nvec);
683:     PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);
684:     switch (ctx->dos) {
685:       case EPS_EVSL_DOS_KPM:
686:         PetscViewerASCIIPrintf(viewer,"degree=%" PetscInt_FMT "\n",ctx->deg);
687:         break;
688:       case EPS_EVSL_DOS_LANCZOS:
689:         PetscViewerASCIIPrintf(viewer,"steps=%" PetscInt_FMT ", npoints=%" PetscInt_FMT "\n",ctx->steps,ctx->npoints);
690:         break;
691:     }
692:     PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);
693:     PetscViewerASCIIPrintf(viewer,"  polynomial parameters: max degree = %" PetscInt_FMT ", threshold = %g\n",ctx->max_deg,(double)ctx->thresh);
694:   }
695:   PetscFunctionReturn(0);
696: }

698: PetscErrorCode EPSSetFromOptions_EVSL(PetscOptionItems *PetscOptionsObject,EPS eps)
699: {
700:   PetscReal        array[2]={0,0},th;
701:   PetscInt         k,i1,i2,i3,i4;
702:   PetscBool        flg,flg1;
703:   EPSEVSLDOSMethod dos;
704:   EPSEVSLDamping   damping;
705:   EPS_EVSL         *ctx = (EPS_EVSL*)eps->data;

707:   PetscOptionsHead(PetscOptionsObject,"EPS EVSL Options");

709:     k = 2;
710:     PetscOptionsRealArray("-eps_evsl_range","Interval containing all eigenvalues (two real values separated with a comma without spaces)","EPSEVSLSetRange",array,&k,&flg);
711:     if (flg) {
713:       EPSEVSLSetRange(eps,array[0],array[1]);
714:     }

716:     PetscOptionsInt("-eps_evsl_slices","Number of slices","EPSEVSLSetSlices",ctx->nslices,&i1,&flg);
717:     if (flg) EPSEVSLSetSlices(eps,i1);

719:     PetscOptionsEnum("-eps_evsl_damping","Type of damping","EPSEVSLSetDamping",EPSEVSLDampings,(PetscEnum)ctx->damping,(PetscEnum*)&damping,&flg);
720:     if (flg) EPSEVSLSetDamping(eps,damping);

722:     EPSEVSLGetDOSParameters(eps,&dos,&i1,&i2,&i3,&i4);
723:     PetscOptionsEnum("-eps_evsl_dos_method","Method to compute the DOS","EPSEVSLSetDOSParameters",EPSEVSLDOSMethods,(PetscEnum)ctx->dos,(PetscEnum*)&dos,&flg);
724:     PetscOptionsInt("-eps_evsl_dos_nvec","Number of sample vectors for DOS","EPSEVSLSetDOSParameters",i1,&i1,&flg1);
725:     if (flg1) flg = PETSC_TRUE;
726:     PetscOptionsInt("-eps_evsl_dos_degree","Polynomial degree used for DOS","EPSEVSLSetDOSParameters",i2,&i2,&flg1);
727:     if (flg1) flg = PETSC_TRUE;
728:     PetscOptionsInt("-eps_evsl_dos_steps","Number of Lanczos steps in DOS","EPSEVSLSetDOSParameters",i3,&i3,&flg1);
729:     if (flg1) flg = PETSC_TRUE;
730:     PetscOptionsInt("-eps_evsl_dos_npoints","Number of sample points used for DOS","EPSEVSLSetDOSParameters",i4,&i4,&flg1);
731:     if (flg || flg1) EPSEVSLSetDOSParameters(eps,dos,i1,i2,i3,i4);

733:     EPSEVSLGetPolParameters(eps,&i1,&th);
734:     PetscOptionsInt("-eps_evsl_pol_max_deg","Maximum degree allowed for the polynomial","EPSEVSLSetPolParameters",i1,&i1,&flg);
735:     PetscOptionsReal("-eps_evsl_pol_threshold","Threshold for accepting polynomial","EPSEVSLSetPolParameters",th,&th,&flg1);
736:     if (flg || flg1) EPSEVSLSetPolParameters(eps,i1,th);

738:   PetscOptionsTail();
739:   PetscFunctionReturn(0);
740: }

742: PetscErrorCode EPSDestroy_EVSL(EPS eps)
743: {
744:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

746:   if (ctx->initialized) EVSLFinish();
747:   PetscLayoutDestroy(&ctx->map);
748:   PetscFree(ctx->sli);
749:   PetscFree(eps->data);
750:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetRange_C",NULL);
751:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetRange_C",NULL);
752:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetSlices_C",NULL);
753:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetSlices_C",NULL);
754:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDOSParameters_C",NULL);
755:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDOSParameters_C",NULL);
756:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetPolParameters_C",NULL);
757:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetPolParameters_C",NULL);
758:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDamping_C",NULL);
759:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDamping_C",NULL);
760:   PetscFunctionReturn(0);
761: }

763: PetscErrorCode EPSReset_EVSL(EPS eps)
764: {
765:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

767:   MatDestroy(&ctx->A);
768:   VecDestroy(&ctx->x);
769:   VecDestroy(&ctx->y);
770:   PetscFunctionReturn(0);
771: }

773: SLEPC_EXTERN PetscErrorCode EPSCreate_EVSL(EPS eps)
774: {
775:   EPS_EVSL       *ctx;

777:   PetscNewLog(eps,&ctx);
778:   eps->data = (void*)ctx;

780:   ctx->nslices = 0;
781:   ctx->lmin    = PETSC_MIN_REAL;
782:   ctx->lmax    = PETSC_MAX_REAL;
783:   ctx->dos     = EPS_EVSL_DOS_KPM;
784:   ctx->nvec    = 80;
785:   ctx->deg     = 300;
786:   ctx->steps   = 40;
787:   ctx->npoints = 200;
788:   ctx->max_deg = 10000;
789:   ctx->thresh  = 0.8;
790:   ctx->damping = EPS_EVSL_DAMPING_SIGMA;

792:   eps->categ = EPS_CATEGORY_OTHER;

794:   eps->ops->solve          = EPSSolve_EVSL;
795:   eps->ops->setup          = EPSSetUp_EVSL;
796:   eps->ops->setupsort      = EPSSetUpSort_Basic;
797:   eps->ops->setfromoptions = EPSSetFromOptions_EVSL;
798:   eps->ops->destroy        = EPSDestroy_EVSL;
799:   eps->ops->reset          = EPSReset_EVSL;
800:   eps->ops->view           = EPSView_EVSL;
801:   eps->ops->backtransform  = EPSBackTransform_Default;
802:   eps->ops->setdefaultst   = EPSSetDefaultST_NoFactor;

804:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetRange_C",EPSEVSLSetRange_EVSL);
805:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetRange_C",EPSEVSLGetRange_EVSL);
806:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetSlices_C",EPSEVSLSetSlices_EVSL);
807:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetSlices_C",EPSEVSLGetSlices_EVSL);
808:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDOSParameters_C",EPSEVSLSetDOSParameters_EVSL);
809:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDOSParameters_C",EPSEVSLGetDOSParameters_EVSL);
810:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetPolParameters_C",EPSEVSLSetPolParameters_EVSL);
811:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetPolParameters_C",EPSEVSLGetPolParameters_EVSL);
812:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDamping_C",EPSEVSLSetDamping_EVSL);
813:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDamping_C",EPSEVSLGetDamping_EVSL);
814:   PetscFunctionReturn(0);
815: }