Actual source code: evsl.c

slepc-3.15.0 2021-03-31
Report Typos and Errors
  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2021, 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: typedef struct {
 18:   PetscBool         initialized;
 19:   Mat               A;           /* problem matrix */
 20:   Vec               x,y;         /* auxiliary vectors */
 21:   PetscReal         *sli;        /* slice bounds */
 22:   PetscInt          nev;         /* approximate number of wanted eigenvalues in each slice */
 23:   PetscLayout       map;         /* used to distribute slices among MPI processes */
 24:   PetscBool         estimrange;  /* the filter range was not set by the user */
 25:   /* user parameters */
 26:   PetscInt          nslices;     /* number of slices */
 27:   PetscReal         lmin,lmax;   /* numerical range (min and max eigenvalue) */
 28:   EPSEVSLDOSMethod  dos;         /* DOS method, either KPM or Lanczos */
 29:   PetscInt          nvec;        /* number of sample vectors used for DOS */
 30:   PetscInt          deg;         /* polynomial degree used for DOS (KPM only) */
 31:   PetscInt          steps;       /* number of Lanczos steps used for DOS (Lanczos only) */
 32:   PetscInt          npoints;     /* number of sample points used for DOS (Lanczos only) */
 33:   PetscInt          max_deg;     /* maximum degree allowed for the polynomial */
 34:   PetscReal         thresh;      /* threshold for accepting polynomial */
 35:   EPSEVSLDamping    damping;     /* type of damping (for polynomial and for DOS-KPM) */
 36: } EPS_EVSL;

 38: static void AMatvec_EVSL(double *xa,double *ya,void *data)
 39: {
 41:   EPS_EVSL       *ctx = (EPS_EVSL*)data;
 42:   Vec            x = ctx->x,y = ctx->y;
 43:   Mat            A = ctx->A;

 46:   VecPlaceArray(x,(PetscScalar*)xa);CHKERRABORT(PetscObjectComm((PetscObject)A),ierr);
 47:   VecPlaceArray(y,(PetscScalar*)ya);CHKERRABORT(PetscObjectComm((PetscObject)A),ierr);
 48:   MatMult(A,x,y);CHKERRABORT(PetscObjectComm((PetscObject)A),ierr);
 49:   VecResetArray(x);CHKERRABORT(PetscObjectComm((PetscObject)A),ierr);
 50:   VecResetArray(y);CHKERRABORT(PetscObjectComm((PetscObject)A),ierr);
 51:   PetscFunctionReturnVoid();
 52: }

 54: PetscErrorCode EPSSetUp_EVSL(EPS eps)
 55: {
 57:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;
 58:   PetscMPIInt    size,rank;
 59:   PetscBool      isshift;
 60:   PetscScalar    *vinit;
 61:   PetscReal      *mu,ecount,xintv[4],*xdos,*ydos;
 62:   Vec            v0;
 63:   Mat            A;
 64:   PetscRandom    rnd;

 67:   EPSCheckStandard(eps);
 68:   EPSCheckHermitian(eps);
 69:   PetscObjectTypeCompare((PetscObject)eps->st,STSHIFT,&isshift);
 70:   if (!isshift) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver does not support spectral transformations");

 72:   if (ctx->initialized) EVSLFinish();
 73:   EVSLStart();
 74:   ctx->initialized=PETSC_TRUE;

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

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

101:   if (!eps->which) eps->which=EPS_ALL;
102:   if (eps->which!=EPS_ALL || eps->inta==eps->intb) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver requires setting an interval with EPSSetInterval()");

104:   /* estimate numerical range */
105:   if (ctx->estimrange || ctx->lmin == PETSC_MIN_REAL || ctx->lmax == PETSC_MAX_REAL) {
106:     MatCreateVecs(ctx->A,&v0,NULL);
107:     if (!eps->V) { EPSGetBV(eps,&eps->V); }
108:     BVGetRandomContext(eps->V,&rnd);
109:     VecSetRandom(v0,rnd);
110:     VecGetArray(v0,&vinit);
111:     LanTrbounds(50,200,eps->tol,vinit,1,&ctx->lmin,&ctx->lmax,NULL);
112:     VecRestoreArray(v0,&vinit);
113:     VecDestroy(&v0);
114:     ctx->estimrange = PETSC_TRUE;   /* estimate if called again with another matrix */
115:   }
116:   if (ctx->lmin > eps->inta || ctx->lmax < eps->intb) SETERRQ4(PetscObjectComm((PetscObject)eps),1,"The requested interval [%g,%g] must be contained in the numerical range [%g,%g]",(double)eps->inta,(double)eps->intb,(double)ctx->lmin,(double)ctx->lmax);
117:   xintv[0] = eps->inta;
118:   xintv[1] = eps->intb;
119:   xintv[2] = ctx->lmin;
120:   xintv[3] = ctx->lmax;

122:   /* estimate number of eigenvalues in the interval */
123:   if (ctx->dos == EPS_EVSL_DOS_KPM) {
124:     PetscMalloc1(ctx->deg+1,&mu);
125:     if (!rank) { kpmdos(ctx->deg,(int)ctx->damping,ctx->nvec,xintv,mu,&ecount); }
126:     MPI_Bcast(mu,ctx->deg+1,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);
127:   } else if (ctx->dos == EPS_EVSL_DOS_LANCZOS) {
128:     PetscMalloc2(ctx->npoints,&xdos,ctx->npoints,&ydos);
129:     if (!rank) { LanDos(ctx->nvec,PetscMin(ctx->steps,eps->n/2),ctx->npoints,xdos,ydos,&ecount,xintv); }
130:     MPI_Bcast(xdos,ctx->npoints,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);
131:     MPI_Bcast(ydos,ctx->npoints,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);
132:   } else SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid DOS method");
133:   MPI_Bcast(&ecount,1,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);

135:   PetscInfo1(eps,"Estimated eigenvalue count in the interval: %g\n",ecount);
136:   eps->ncv = (PetscInt)PetscCeilReal(1.5*ecount);

138:   /* slice the spectrum */
139:   PetscFree(ctx->sli);
140:   PetscMalloc1(ctx->nslices+1,&ctx->sli);
141:   if (ctx->dos == EPS_EVSL_DOS_KPM) {
142:     spslicer(ctx->sli,mu,ctx->deg,xintv,ctx->nslices,10*(PetscInt)ecount);
143:     PetscFree(mu);
144:   } else if (ctx->dos == EPS_EVSL_DOS_LANCZOS) {
145:     spslicer2(xdos,ydos,ctx->nslices,ctx->npoints,ctx->sli);
146:     PetscFree2(xdos,ydos);
147:   }

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

152:   if (eps->mpd!=PETSC_DEFAULT) { PetscInfo(eps,"Warning: parameter mpd ignored\n"); }
153:   if (eps->max_it==PETSC_DEFAULT) eps->max_it = 1;
154:   EPSAllocateSolution(eps,0);
155:   return(0);
156: }

158: PetscErrorCode EPSSolve_EVSL(EPS eps)
159: {
161:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;
162:   PetscInt       i,j,k=0,sl,mlan,nevout,*ind,nevmax,rstart,rend,*nevloc,*disp,N;
163:   PetscReal      *res,xintv[4],*errest;
164:   PetscScalar    *lam,*X,*Y,*vinit,*eigr;
165:   PetscMPIInt    size,rank;
166:   PetscRandom    rnd;
167:   Vec            v,w,v0,x;
168:   VecScatter     vs;
169:   IS             is;
170:   polparams      pol;

173:   MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);CHKERRMPI(ierr);
174:   MPI_Comm_rank(PetscObjectComm((PetscObject)eps),&rank);CHKERRMPI(ierr);
175:   PetscLayoutGetRange(ctx->map,&rstart,&rend);
176:   nevmax = (rend-rstart)*ctx->nev;
177:   MatCreateVecs(ctx->A,&v0,NULL);
178:   BVGetRandomContext(eps->V,&rnd);
179:   VecSetRandom(v0,rnd);
180:   VecGetArray(v0,&vinit);
181:   PetscMalloc5(size,&nevloc,size+1,&disp,nevmax,&eigr,nevmax,&errest,nevmax*eps->n,&X);
182:   mlan = PetscMin(PetscMax(5*ctx->nev,300),eps->n);
183:   for (sl=rstart; sl<rend; sl++) {
184:     xintv[0] = ctx->sli[sl];
185:     xintv[1] = ctx->sli[sl+1];
186:     xintv[2] = ctx->lmin;
187:     xintv[3] = ctx->lmax;
188:     PetscInfo3(ctx->A,"Subinterval %D: [%.4e, %.4e]\n",sl+1,xintv[0],xintv[1]);
189:     set_pol_def(&pol);
190:     pol.max_deg    = ctx->max_deg;
191:     pol.damping    = (int)ctx->damping;
192:     pol.thresh_int = ctx->thresh;
193:     find_pol(xintv,&pol);
194:     PetscInfo4(ctx->A,"Polynomial [type = %D], deg %D, bar %e gam %e\n",pol.type,pol.deg,pol.bar,pol.gam);
195:     ChebLanNr(xintv,mlan,eps->tol,vinit,&pol,&nevout,&lam,&Y,&res,NULL);
196:     if (k+nevout>nevmax) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_LIB,"Too low estimation of eigenvalue count, try modifying the sampling parameters");
197:     free_pol(&pol);
198:     PetscInfo1(ctx->A,"Computed %D eigenvalues\n",nevout);
199:     PetscMalloc1(nevout,&ind);
200:     sort_double(nevout,lam,ind);
201:     for (i=0;i<nevout;i++) {
202:       eigr[i+k]   = lam[i];
203:       errest[i+k] = res[ind[i]];
204:       PetscArraycpy(X+(i+k)*eps->n,Y+ind[i]*eps->n,eps->n);
205:     }
206:     k += nevout;
207:     if (lam) evsl_Free(lam);
208:     if (Y)   evsl_Free_device(Y);
209:     if (res) evsl_Free(res);
210:     PetscFree(ind);
211:   }
212:   VecRestoreArray(v0,&vinit);
213:   VecDestroy(&v0);

215:   /* gather eigenvalues computed by each MPI process */
216:   MPI_Allgather(&k,1,MPIU_INT,nevloc,1,MPIU_INT,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);
217:   eps->nev = nevloc[0];
218:   disp[0]  = 0;
219:   for (i=1;i<size;i++) {
220:     eps->nev += nevloc[i];
221:     disp[i]   = disp[i-1]+nevloc[i-1];
222:   }
223:   disp[size] = disp[size-1]+nevloc[size-1];
224:   if (eps->nev>eps->ncv) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_LIB,"Too low estimation of eigenvalue count, try modifying the sampling parameters");
225:   MPI_Allgatherv(eigr,k,MPIU_SCALAR,eps->eigr,nevloc,disp,MPIU_SCALAR,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);
226:   MPI_Allgatherv(errest,k,MPIU_REAL,eps->errest,nevloc,disp,MPIU_REAL,PetscObjectComm((PetscObject)eps));CHKERRMPI(ierr);
227:   eps->nconv  = eps->nev;
228:   eps->its    = 1;
229:   eps->reason = EPS_CONVERGED_TOL;

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

256: static PetscErrorCode EPSEVSLSetSlices_EVSL(EPS eps,PetscInt nslices)
257: {
258:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

261:   if (nslices == PETSC_DECIDE || nslices == PETSC_DEFAULT) nslices = 0;
262:   else if (nslices<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Number of slices must be 1 at least");
263:   if (ctx->nslices != nslices) {
264:     ctx->nslices = nslices;
265:     eps->state   = EPS_STATE_INITIAL;
266:   }
267:   return(0);
268: }

270: /*@
271:    EPSEVSLSetSlices - Set the number of slices in which the interval must be
272:    subdivided.

274:    Logically Collective on eps

276:    Input Parameters:
277: +  eps     - the eigensolver context
278: -  nslices - the number of slices

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

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

288:    Level: intermediate

290: .seealso: EPSEVSLGetSlices()
291: @*/
292: PetscErrorCode EPSEVSLSetSlices(EPS eps,PetscInt nslices)
293: {

299:   PetscTryMethod(eps,"EPSEVSLSetSlices_C",(EPS,PetscInt),(eps,nslices));
300:   return(0);
301: }

303: static PetscErrorCode EPSEVSLGetSlices_EVSL(EPS eps,PetscInt *nslices)
304: {
305:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

308:   *nslices = ctx->nslices;
309:   return(0);
310: }

312: /*@
313:    EPSEVSLGetSlices - Gets the number of slices in which the interval must be
314:    subdivided.

316:    Not Collective

318:    Input Parameter:
319: .  eps - the eigensolver context

321:    Output Parameter:
322: .  nslices - the number of slices

324:    Level: intermediate

326: .seealso: EPSEVSLSetSlices()
327: @*/
328: PetscErrorCode EPSEVSLGetSlices(EPS eps,PetscInt *nslices)
329: {

335:   PetscUseMethod(eps,"EPSEVSLGetSlices_C",(EPS,PetscInt*),(eps,nslices));
336:   return(0);
337: }

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

344:   if (lmin>lmax) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Badly defined interval, must be lmin<lmax");
345:   if (ctx->lmin != lmin || ctx->lmax != lmax) {
346:     ctx->lmin  = lmin;
347:     ctx->lmax  = lmax;
348:     eps->state = EPS_STATE_INITIAL;
349:   }
350:   return(0);
351: }

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

357:    Logically Collective on eps

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

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

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

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

375:    Level: intermediate

377: .seealso: EPSEVSLGetRange(), EPSSetInterval()
378: @*/
379: PetscErrorCode EPSEVSLSetRange(EPS eps,PetscReal lmin,PetscReal lmax)
380: {

387:   PetscTryMethod(eps,"EPSEVSLSetRange_C",(EPS,PetscReal,PetscReal),(eps,lmin,lmax));
388:   return(0);
389: }

391: static PetscErrorCode EPSEVSLGetRange_EVSL(EPS eps,PetscReal *lmin,PetscReal *lmax)
392: {
393:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

396:   if (lmin) *lmin = ctx->lmin;
397:   if (lmax) *lmax = ctx->lmax;
398:   return(0);
399: }

401: /*@
402:    EPSEVSLGetRange - Gets the interval containing all eigenvalues.

404:    Not Collective

406:    Input Parameter:
407: .  eps - the eigensolver context

409:    Output Parameters:
410: +  lmin - left end of the interval
411: -  lmax - right end of the interval

413:    Level: intermediate

415: .seealso: EPSEVSLSetRange()
416: @*/
417: PetscErrorCode EPSEVSLGetRange(EPS eps,PetscReal *lmin,PetscReal *lmax)
418: {

423:   PetscUseMethod(eps,"EPSEVSLGetRange_C",(EPS,PetscReal*,PetscReal*),(eps,lmin,lmax));
424:   return(0);
425: }

427: static PetscErrorCode EPSEVSLSetDOSParameters_EVSL(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)
428: {
429:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

432:   ctx->dos = dos;
433:   if (nvec == PETSC_DECIDE || nvec == PETSC_DEFAULT) ctx->nvec = 80;
434:   else if (nvec<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The nvec argument must be > 0");
435:   else ctx->nvec = nvec;
436:   switch (dos) {
437:     case EPS_EVSL_DOS_KPM:
438:       if (deg == PETSC_DECIDE || deg == PETSC_DEFAULT) ctx->deg = 300;
439:       else if (deg<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The deg argument must be > 0");
440:       else ctx->deg = deg;
441:       break;
442:     case EPS_EVSL_DOS_LANCZOS:
443:       if (steps == PETSC_DECIDE || steps == PETSC_DEFAULT) ctx->steps = 40;
444:       else if (steps<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The steps argument must be > 0");
445:       else ctx->steps = steps;
446:       if (npoints == PETSC_DECIDE || npoints == PETSC_DEFAULT) ctx->npoints = 200;
447:       else if (npoints<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The npoints argument must be > 0");
448:       else ctx->npoints = npoints;
449:       break;
450:   }
451:   eps->state = EPS_STATE_INITIAL;
452:   return(0);
453: }

455: /*@
456:    EPSEVSLSetDOSParameters - Defines the parameters used for computing the
457:    density of states (DOS) in the EVSL solver.

459:    Logically Collective on eps

461:    Input Parameters:
462: +  eps     - the eigensolver context
463: .  dos     - DOS method, either KPM or Lanczos
464: .  nvec    - number of sample vectors
465: .  deg     - polynomial degree (KPM only)
466: .  steps   - number of Lanczos steps (Lanczos only)
467: -  npoints - number of sample points (Lanczos only)

469:    Options Database Keys:
470: +  -eps_evsl_dos_method <dos> - set the DOS method, either kpm or lanczos
471: .  -eps_evsl_dos_nvec <n> - set the number of sample vectors
472: .  -eps_evsl_dos_degree <n> - set the polynomial degree
473: .  -eps_evsl_dos_steps <n> - set the number of Lanczos steps
474: -  -eps_evsl_dos_npoints <n> - set the number of sample points

476:    Notes:
477:    The density of states (or spectral density) can be approximated with two
478:    methods: kernel polynomial method (KPM) or Lanczos. Some parameters for
479:    these methods can be set by the user with this function, with some of
480:    them being relevant for one of the methods only.

482:    Level: intermediate

484: .seealso: EPSEVSLGetDOSParameters()
485: @*/
486: PetscErrorCode EPSEVSLSetDOSParameters(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)
487: {

497:   PetscTryMethod(eps,"EPSEVSLSetDOSParameters_C",(EPS,EPSEVSLDOSMethod,PetscInt,PetscInt,PetscInt,PetscInt),(eps,dos,nvec,deg,steps,npoints));
498:   return(0);
499: }

501: static PetscErrorCode EPSEVSLGetDOSParameters_EVSL(EPS eps,EPSEVSLDOSMethod *dos,PetscInt *nvec,PetscInt *deg,PetscInt *steps,PetscInt *npoints)
502: {
503:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

506:   if (dos)     *dos     = ctx->dos;
507:   if (nvec)    *nvec    = ctx->nvec;
508:   if (deg)     *deg     = ctx->deg;
509:   if (steps)   *steps   = ctx->steps;
510:   if (npoints) *npoints = ctx->npoints;
511:   return(0);
512: }

514: /*@
515:    EPSEVSLGetDOSParameters - Gets the parameters used for computing the
516:    density of states (DOS) in the EVSL solver.

518:    Not Collective

520:    Input Parameter:
521: .  eps - the eigensolver context

523:    Output Parameters:
524: +  dos     - DOS method, either KPM or Lanczos
525: .  nvec    - number of sample vectors
526: .  deg     - polynomial degree (KPM only)
527: .  steps   - number of Lanczos steps (Lanczos only)
528: -  npoints - number of sample points (Lanczos only)

530:    Level: intermediate

532: .seealso: EPSEVSLSetDOSParameters()
533: @*/
534: PetscErrorCode EPSEVSLGetDOSParameters(EPS eps,EPSEVSLDOSMethod *dos,PetscInt *nvec,PetscInt *deg,PetscInt *steps,PetscInt *npoints)
535: {

540:   PetscUseMethod(eps,"EPSEVSLGetDOSParameters_C",(EPS,EPSEVSLDOSMethod*,PetscInt*,PetscInt*,PetscInt*,PetscInt*),(eps,dos,nvec,deg,steps,npoints));
541:   return(0);
542: }

544: static PetscErrorCode EPSEVSLSetPolParameters_EVSL(EPS eps,PetscInt max_deg,PetscReal thresh)
545: {
546:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

549:   if (max_deg == PETSC_DECIDE || max_deg == PETSC_DEFAULT) ctx->max_deg = 10000;
550:   else if (max_deg<3) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The max_deg argument must be > 2");
551:   else ctx->max_deg = max_deg;
552:   if (thresh == PETSC_DECIDE || thresh == PETSC_DEFAULT) ctx->thresh = 0.8;
553:   else if (thresh<0.0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The thresh argument must be > 0.0");
554:   else ctx->thresh = thresh;
555:   eps->state = EPS_STATE_INITIAL;
556:   return(0);
557: }

559: /*@
560:    EPSEVSLSetPolParameters - Defines the parameters used for building the
561:    building the polynomial in the EVSL solver.

563:    Logically Collective on eps

565:    Input Parameters:
566: +  eps     - the eigensolver context
567: .  max_deg - maximum degree allowed for the polynomial
568: -  thresh  - threshold for accepting polynomial

570:    Options Database Keys:
571: +  -eps_evsl_pol_max_deg <d> - set maximum polynomial degree
572: -  -eps_evsl_pol_thresh <t> - set the threshold

574:    Level: intermediate

576: .seealso: EPSEVSLGetPolParameters()
577: @*/
578: PetscErrorCode EPSEVSLSetPolParameters(EPS eps,PetscInt max_deg,PetscReal thresh)
579: {

586:   PetscTryMethod(eps,"EPSEVSLSetPolParameters_C",(EPS,PetscInt,PetscReal),(eps,max_deg,thresh));
587:   return(0);
588: }

590: static PetscErrorCode EPSEVSLGetPolParameters_EVSL(EPS eps,PetscInt *max_deg,PetscReal *thresh)
591: {
592:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

595:   if (max_deg) *max_deg = ctx->max_deg;
596:   if (thresh)  *thresh  = ctx->thresh;
597:   return(0);
598: }

600: /*@
601:    EPSEVSLGetPolParameters - Gets the parameters used for building the
602:    polynomial in the EVSL solver.

604:    Not Collective

606:    Input Parameter:
607: .  eps - the eigensolver context

609:    Output Parameters:
610: +  max_deg - the maximum degree of the polynomial
611: -  thresh  - the threshold

613:    Level: intermediate

615: .seealso: EPSEVSLSetPolParameters()
616: @*/
617: PetscErrorCode EPSEVSLGetPolParameters(EPS eps,PetscInt *max_deg,PetscReal *thresh)
618: {

623:   PetscUseMethod(eps,"EPSEVSLGetPolParameters_C",(EPS,PetscInt*,PetscReal*),(eps,max_deg,thresh));
624:   return(0);
625: }

627: static PetscErrorCode EPSEVSLSetDamping_EVSL(EPS eps,EPSEVSLDamping damping)
628: {
629:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

632:   if (ctx->damping != damping) {
633:     ctx->damping = damping;
634:     eps->state   = EPS_STATE_INITIAL;
635:   }
636:   return(0);
637: }

639: /*@
640:    EPSEVSLSetDamping - Set the type of damping to be used in EVSL.

642:    Logically Collective on eps

644:    Input Parameters:
645: +  eps     - the eigensolver context
646: -  damping - the type of damping

648:    Options Database Key:
649: .  -eps_evsl_damping <n> - set the type of damping

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

655:    Level: intermediate

657: .seealso: EPSEVSLGetDamping(), EPSEVSLSetDOSParameters()
658: @*/
659: PetscErrorCode EPSEVSLSetDamping(EPS eps,EPSEVSLDamping damping)
660: {

666:   PetscTryMethod(eps,"EPSEVSLSetDamping_C",(EPS,EPSEVSLDamping),(eps,damping));
667:   return(0);
668: }

670: static PetscErrorCode EPSEVSLGetDamping_EVSL(EPS eps,EPSEVSLDamping *damping)
671: {
672:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

675:   *damping = ctx->damping;
676:   return(0);
677: }

679: /*@
680:    EPSEVSLGetDamping - Gets the type of damping.

682:    Not Collective

684:    Input Parameter:
685: .  eps - the eigensolver context

687:    Output Parameter:
688: .  damping - the type of damping

690:    Level: intermediate

692: .seealso: EPSEVSLSetDamping()
693: @*/
694: PetscErrorCode EPSEVSLGetDamping(EPS eps,EPSEVSLDamping *damping)
695: {

701:   PetscUseMethod(eps,"EPSEVSLGetDamping_C",(EPS,EPSEVSLDamping*),(eps,damping));
702:   return(0);
703: }

705: PetscErrorCode EPSView_EVSL(EPS eps,PetscViewer viewer)
706: {
708:   PetscBool      isascii;
709:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

712:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
713:   if (isascii) {
714:     PetscViewerASCIIPrintf(viewer,"  numerical range = [%g,%g]\n",(double)ctx->lmin,(double)ctx->lmax);
715:     PetscViewerASCIIPrintf(viewer,"  number of slices = %D\n",ctx->nslices);
716:     PetscViewerASCIIPrintf(viewer,"  type of damping = %s\n",EPSEVSLDampings[ctx->damping]);
717:     PetscViewerASCIIPrintf(viewer,"  computing DOS with %s: nvec=%D, ",EPSEVSLDOSMethods[ctx->dos],ctx->nvec);
718:     PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);
719:     switch (ctx->dos) {
720:       case EPS_EVSL_DOS_KPM:
721:         PetscViewerASCIIPrintf(viewer,"degree=%D\n",ctx->deg);
722:         break;
723:       case EPS_EVSL_DOS_LANCZOS:
724:         PetscViewerASCIIPrintf(viewer,"steps=%D, npoints=%D\n",ctx->steps,ctx->npoints);
725:         break;
726:     }
727:     PetscViewerASCIIPrintf(viewer,"  polynomial parameters: max degree = %D, threshold = %g\n",ctx->max_deg,(double)ctx->thresh);
728:     PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);
729:   }
730:   return(0);
731: }

733: PetscErrorCode EPSSetFromOptions_EVSL(PetscOptionItems *PetscOptionsObject,EPS eps)
734: {
735:   PetscErrorCode   ierr;
736:   PetscReal        array[2]={0,0},th;
737:   PetscInt         k,i1,i2,i3,i4;
738:   PetscBool        flg,flg1;
739:   EPSEVSLDOSMethod dos;
740:   EPSEVSLDamping   damping;
741:   EPS_EVSL         *ctx = (EPS_EVSL*)eps->data;

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

746:     k = 2;
747:     PetscOptionsRealArray("-eps_evsl_range","Interval containing all eigenvalues (two real values separated with a comma without spaces)","EPSEVSLSetRange",array,&k,&flg);
748:     if (flg) {
749:       if (k<2) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_SIZ,"Must pass two values in -eps_evsl_range (comma-separated without spaces)");
750:       EPSEVSLSetRange(eps,array[0],array[1]);
751:     }

753:     PetscOptionsInt("-eps_evsl_slices","Number of slices","EPSEVSLSetSlices",ctx->nslices,&i1,&flg);
754:     if (flg) { EPSEVSLSetSlices(eps,i1); }

756:     PetscOptionsEnum("-eps_evsl_damping","Type of damping","EPSEVSLSetDamping",EPSEVSLDampings,(PetscEnum)ctx->damping,(PetscEnum*)&damping,&flg);
757:     if (flg) { EPSEVSLSetDamping(eps,damping); }

759:     EPSEVSLGetDOSParameters(eps,&dos,&i1,&i2,&i3,&i4);
760:     PetscOptionsEnum("-eps_evsl_dos_method","Method to compute the DOS","EPSEVSLSetDOSParameters",EPSEVSLDOSMethods,(PetscEnum)ctx->dos,(PetscEnum*)&dos,&flg);
761:     PetscOptionsInt("-eps_evsl_dos_nvec","Number of sample vectors for DOS","EPSEVSLSetDOSParameters",i1,&i1,&flg1);
762:     flg = flg || flg1;
763:     PetscOptionsInt("-eps_evsl_dos_degree","Polynomial degree used for DOS","EPSEVSLSetDOSParameters",i2,&i2,&flg1);
764:     flg = flg || flg1;
765:     PetscOptionsInt("-eps_evsl_dos_steps","Number of Lanczos steps in DOS","EPSEVSLSetDOSParameters",i3,&i3,&flg1);
766:     flg = flg || flg1;
767:     PetscOptionsInt("-eps_evsl_dos_npoints","Number of sample points used for DOS","EPSEVSLSetDOSParameters",i4,&i4,&flg1);
768:     if (flg || flg1) { EPSEVSLSetDOSParameters(eps,dos,i1,i2,i3,i4); }

770:     EPSEVSLGetPolParameters(eps,&i1,&th);
771:     PetscOptionsInt("-eps_evsl_pol_max_deg","Maximum degree allowed for the polynomial","EPSEVSLSetPolParameters",i1,&i1,&flg);
772:     PetscOptionsReal("-eps_evsl_pol_threshold","Threshold for accepting polynomial","EPSEVSLSetPolParameters",th,&th,&flg1);
773:     if (flg || flg1) { EPSEVSLSetPolParameters(eps,i1,th); }

775:   PetscOptionsTail();
776:   return(0);
777: }

779: PetscErrorCode EPSDestroy_EVSL(EPS eps)
780: {
782:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

785:   if (ctx->initialized) EVSLFinish();
786:   PetscLayoutDestroy(&ctx->map);
787:   PetscFree(ctx->sli);
788:   PetscFree(eps->data);
789:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetRange_C",NULL);
790:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetRange_C",NULL);
791:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetSlices_C",NULL);
792:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetSlices_C",NULL);
793:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDOSParameters_C",NULL);
794:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDOSParameters_C",NULL);
795:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetPolParameters_C",NULL);
796:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetPolParameters_C",NULL);
797:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDamping_C",NULL);
798:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDamping_C",NULL);
799:   return(0);
800: }

802: PetscErrorCode EPSReset_EVSL(EPS eps)
803: {
805:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

808:   MatDestroy(&ctx->A);
809:   VecDestroy(&ctx->x);
810:   VecDestroy(&ctx->y);
811:   return(0);
812: }

814: SLEPC_EXTERN PetscErrorCode EPSCreate_EVSL(EPS eps)
815: {
816:   EPS_EVSL       *ctx;

820:   PetscNewLog(eps,&ctx);
821:   eps->data = (void*)ctx;

823:   ctx->nslices = 0;
824:   ctx->lmin    = PETSC_MIN_REAL;
825:   ctx->lmax    = PETSC_MAX_REAL;
826:   ctx->dos     = EPS_EVSL_DOS_KPM;
827:   ctx->nvec    = 80;
828:   ctx->deg     = 300;
829:   ctx->steps   = 40;
830:   ctx->npoints = 200;
831:   ctx->max_deg = 10000;
832:   ctx->thresh  = 0.8;
833:   ctx->damping = EPS_EVSL_DAMPING_SIGMA;

835:   eps->categ = EPS_CATEGORY_OTHER;

837:   eps->ops->solve          = EPSSolve_EVSL;
838:   eps->ops->setup          = EPSSetUp_EVSL;
839:   eps->ops->setupsort      = EPSSetUpSort_Basic;
840:   eps->ops->setfromoptions = EPSSetFromOptions_EVSL;
841:   eps->ops->destroy        = EPSDestroy_EVSL;
842:   eps->ops->reset          = EPSReset_EVSL;
843:   eps->ops->view           = EPSView_EVSL;
844:   eps->ops->backtransform  = EPSBackTransform_Default;
845:   eps->ops->setdefaultst   = EPSSetDefaultST_NoFactor;

847:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetRange_C",EPSEVSLSetRange_EVSL);
848:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetRange_C",EPSEVSLGetRange_EVSL);
849:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetSlices_C",EPSEVSLSetSlices_EVSL);
850:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetSlices_C",EPSEVSLGetSlices_EVSL);
851:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDOSParameters_C",EPSEVSLSetDOSParameters_EVSL);
852:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDOSParameters_C",EPSEVSLGetDOSParameters_EVSL);
853:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetPolParameters_C",EPSEVSLSetPolParameters_EVSL);
854:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetPolParameters_C",EPSEVSLGetPolParameters_EVSL);
855:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDamping_C",EPSEVSLSetDamping_EVSL);
856:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDamping_C",EPSEVSLGetDamping_EVSL);
857:   return(0);
858: }