Actual source code: dvdutils.c

slepc-3.11.2 2019-07-30
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2019, 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:    SLEPc eigensolver: "davidson"

 13:    Some utils
 14: */

 16: #include "davidson.h"

 18: typedef struct {
 19:   PC pc;
 20: } dvdPCWrapper;

 22: /*
 23:   Configure the harmonics.
 24:   switch (mode) {
 25:   DVD_HARM_RR:    harmonic RR
 26:   DVD_HARM_RRR:   relative harmonic RR
 27:   DVD_HARM_REIGS: rightmost eigenvalues
 28:   DVD_HARM_LEIGS: largest eigenvalues
 29:   }
 30:   fixedTarged, if true use the target instead of the best eigenvalue
 31:   target, the fixed target to be used
 32: */
 33: typedef struct {
 34:   PetscScalar Wa,Wb;       /* span{W} = span{Wa*AV - Wb*BV} */
 35:   PetscScalar Pa,Pb;       /* H=W'*(Pa*AV - Pb*BV), G=W'*(Wa*AV - Wb*BV) */
 36:   PetscBool   withTarget;
 37:   HarmType_t  mode;
 38: } dvdHarmonic;

 40: typedef struct {
 41:   Vec diagA, diagB;
 42: } dvdJacobiPrecond;

 44: static PetscErrorCode dvd_improvex_precond_d(dvdDashboard *d)
 45: {
 47:   dvdPCWrapper   *dvdpc = (dvdPCWrapper*)d->improvex_precond_data;

 50:   /* Free local data */
 51:   PCDestroy(&dvdpc->pc);
 52:   PetscFree(d->improvex_precond_data);
 53:   return(0);
 54: }

 56: static PetscErrorCode dvd_static_precond_PC_0(dvdDashboard *d,PetscInt i,Vec x,Vec Px)
 57: {
 59:   dvdPCWrapper   *dvdpc = (dvdPCWrapper*)d->improvex_precond_data;

 62:   PCApply(dvdpc->pc,x,Px);
 63:   return(0);
 64: }

 66: /*
 67:   Create a trivial preconditioner
 68: */
 69: static PetscErrorCode dvd_precond_none(dvdDashboard *d,PetscInt i,Vec x,Vec Px)
 70: {

 74:   VecCopy(x,Px);
 75:   return(0);
 76: }

 78: /*
 79:   Create a static preconditioner from a PC
 80: */
 81: PetscErrorCode dvd_static_precond_PC(dvdDashboard *d,dvdBlackboard *b,PC pc)
 82: {
 84:   dvdPCWrapper   *dvdpc;
 85:   Mat            P;
 86:   PetscBool      t0,t1,t2;

 89:   /* Setup the step */
 90:   if (b->state >= DVD_STATE_CONF) {
 91:     /* If the preconditioner is valid */
 92:     if (pc) {
 93:       PetscNewLog(d->eps,&dvdpc);
 94:       dvdpc->pc = pc;
 95:       PetscObjectReference((PetscObject)pc);
 96:       d->improvex_precond_data = dvdpc;
 97:       d->improvex_precond = dvd_static_precond_PC_0;

 99:       /* PC saves the matrix associated with the linear system, and it has to
100:          be initialize to a valid matrix */
101:       PCGetOperatorsSet(pc,NULL,&t0);
102:       PetscObjectTypeCompare((PetscObject)pc,PCNONE,&t1);
103:       PetscObjectTypeCompare((PetscObject)pc,PCSHELL,&t2);
104:       if (t0 && !t1) {
105:         PCGetOperators(pc,NULL,&P);
106:         PetscObjectReference((PetscObject)P);
107:         PCSetOperators(pc,P,P);
108:         PCSetReusePreconditioner(pc,PETSC_TRUE);
109:         MatDestroy(&P);
110:       } else if (t2) {
111:         PCSetOperators(pc,d->A,d->A);
112:         PCSetReusePreconditioner(pc,PETSC_TRUE);
113:       } else {
114:         d->improvex_precond = dvd_precond_none;
115:       }

117:       EPSDavidsonFLAdd(&d->destroyList,dvd_improvex_precond_d);

119:     /* Else, use no preconditioner */
120:     } else d->improvex_precond = dvd_precond_none;
121:   }
122:   return(0);
123: }

125: static PetscErrorCode dvd_harm_d(dvdDashboard *d)
126: {

130:   /* Free local data */
131:   PetscFree(d->calcpairs_W_data);
132:   return(0);
133: }

135: static PetscErrorCode dvd_harm_transf(dvdHarmonic *dvdh,PetscScalar t)
136: {
138:   switch (dvdh->mode) {
139:   case DVD_HARM_RR:    /* harmonic RR */
140:     dvdh->Wa = 1.0; dvdh->Wb = t;   dvdh->Pa = 0.0; dvdh->Pb = -1.0;
141:     break;
142:   case DVD_HARM_RRR:   /* relative harmonic RR */
143:     dvdh->Wa = 1.0; dvdh->Wb = t;   dvdh->Pa = 1.0; dvdh->Pb = 0.0;
144:     break;
145:   case DVD_HARM_REIGS: /* rightmost eigenvalues */
146:     dvdh->Wa = 1.0; dvdh->Wb = t;   dvdh->Pa = 1.0; dvdh->Pb = -PetscConj(t);
147:     break;
148:   case DVD_HARM_LEIGS: /* largest eigenvalues */
149:     dvdh->Wa = 0.0; dvdh->Wb = 1.0; dvdh->Pa = 1.0; dvdh->Pb = 0.0;
150:     break;
151:   case DVD_HARM_NONE:
152:   default:
153:     SETERRQ(PETSC_COMM_SELF,1,"Harmonic type not supported");
154:   }

156:   /* Check the transformation does not change the sign of the imaginary part */
157: #if !defined(PETSC_USE_COMPLEX)
158:   if (dvdh->Pb*dvdh->Wa - dvdh->Wb*dvdh->Pa < 0.0) {
159:     dvdh->Pa *= -1.0;
160:     dvdh->Pb *= -1.0;
161:   }
162: #endif
163:   return(0);
164: }

166: static PetscErrorCode dvd_harm_updateW(dvdDashboard *d)
167: {
168:   dvdHarmonic    *data = (dvdHarmonic*)d->calcpairs_W_data;
170:   PetscInt       l,k;
171:   BV             BX = d->BX?d->BX:d->eps->V;

174:   /* Update the target if it is necessary */
175:   if (!data->withTarget) {
176:     dvd_harm_transf(data,d->eigr[0]);
177:   }

179:   /* W(i) <- Wa*AV(i) - Wb*BV(i) */
180:   BVGetActiveColumns(d->eps->V,&l,&k);
181:   if (k != l+d->V_new_s) SETERRQ(PETSC_COMM_SELF,1,"Consistency broken");
182:   BVSetActiveColumns(d->W,l+d->V_new_s,l+d->V_new_e);
183:   BVSetActiveColumns(d->AX,l+d->V_new_s,l+d->V_new_e);
184:   BVSetActiveColumns(BX,l+d->V_new_s,l+d->V_new_e);
185:   BVCopy(d->AX,d->W);
186:   BVScale(d->W,data->Wa);
187:   BVMult(d->W,-data->Wb,1.0,BX,NULL);
188:   BVSetActiveColumns(d->W,l,k);
189:   BVSetActiveColumns(d->AX,l,k);
190:   BVSetActiveColumns(BX,l,k);
191:   return(0);
192: }

194: static PetscErrorCode dvd_harm_proj(dvdDashboard *d)
195: {
197:   dvdHarmonic    *data = (dvdHarmonic*)d->calcpairs_W_data;
198:   PetscInt       i,j,l0,l,k,ld;
199:   PetscScalar    h,g,*H,*G;

202:   BVGetActiveColumns(d->eps->V,&l0,&k);
203:   l = l0 + d->V_new_s;
204:   k = l0 + d->V_new_e;
205:   MatGetSize(d->H,&ld,NULL);
206:   MatDenseGetArray(d->H,&H);
207:   MatDenseGetArray(d->G,&G);
208:   /* [H G] <- [Pa*H - Pb*G, Wa*H - Wb*G] */
209:   /* Right part */
210:   for (i=l;i<k;i++) {
211:     for (j=l0;j<k;j++) {
212:       h = H[ld*i+j];
213:       g = G[ld*i+j];
214:       H[ld*i+j] = data->Pa*h - data->Pb*g;
215:       G[ld*i+j] = data->Wa*h - data->Wb*g;
216:     }
217:   }
218:   /* Left part */
219:   for (i=l0;i<l;i++) {
220:     for (j=l;j<k;j++) {
221:       h = H[ld*i+j];
222:       g = G[ld*i+j];
223:       H[ld*i+j] = data->Pa*h - data->Pb*g;
224:       G[ld*i+j] = data->Wa*h - data->Wb*g;
225:     }
226:   }
227:   MatDenseRestoreArray(d->H,&H);
228:   MatDenseRestoreArray(d->G,&G);
229:   return(0);
230: }

232: PetscErrorCode dvd_harm_updateproj(dvdDashboard *d)
233: {
235:   dvdHarmonic    *data = (dvdHarmonic*)d->calcpairs_W_data;
236:   PetscInt       i,j,l,k,ld;
237:   PetscScalar    h,g,*H,*G;

240:   BVGetActiveColumns(d->eps->V,&l,&k);
241:   k = l + d->V_tra_s;
242:   MatGetSize(d->H,&ld,NULL);
243:   MatDenseGetArray(d->H,&H);
244:   MatDenseGetArray(d->G,&G);
245:   /* [H G] <- [Pa*H - Pb*G, Wa*H - Wb*G] */
246:   /* Right part */
247:   for (i=l;i<k;i++) {
248:     for (j=0;j<l;j++) {
249:       h = H[ld*i+j];
250:       g = G[ld*i+j];
251:       H[ld*i+j] = data->Pa*h - data->Pb*g;
252:       G[ld*i+j] = data->Wa*h - data->Wb*g;
253:     }
254:   }
255:   /* Lower triangular part */
256:   for (i=0;i<l;i++) {
257:     for (j=l;j<k;j++) {
258:       h = H[ld*i+j];
259:       g = G[ld*i+j];
260:       H[ld*i+j] = data->Pa*h - data->Pb*g;
261:       G[ld*i+j] = data->Wa*h - data->Wb*g;
262:     }
263:   }
264:   MatDenseRestoreArray(d->H,&H);
265:   MatDenseRestoreArray(d->G,&G);
266:   return(0);
267: }

269: static PetscErrorCode dvd_harm_backtrans(dvdHarmonic *data,PetscScalar *ar,PetscScalar *ai)
270: {
271:   PetscScalar xr;
272: #if !defined(PETSC_USE_COMPLEX)
273:   PetscScalar xi, k;
274: #endif

278:   xr = *ar;
279: #if !defined(PETSC_USE_COMPLEX)
281:   xi = *ai;

283:   if (xi != 0.0) {
284:     k = (data->Pa - data->Wa*xr)*(data->Pa - data->Wa*xr) + data->Wa*data->Wa*xi*xi;
285:     *ar = (data->Pb*data->Pa - (data->Pb*data->Wa + data->Wb*data->Pa)*xr + data->Wb*data->Wa*(xr*xr + xi*xi))/k;
286:     *ai = (data->Pb*data->Wa - data->Wb*data->Pa)*xi/k;
287:   } else
288: #endif
289:     *ar = (data->Pb - data->Wb*xr) / (data->Pa - data->Wa*xr);
290:   return(0);
291: }

293: static PetscErrorCode dvd_harm_eig_backtrans(dvdDashboard *d,PetscScalar ar,PetscScalar ai,PetscScalar *br,PetscScalar *bi)
294: {
295:   dvdHarmonic    *data = (dvdHarmonic*)d->calcpairs_W_data;

299:   dvd_harm_backtrans(data,&ar,&ai);
300:   *br = ar;
301:   *bi = ai;
302:   return(0);
303: }

305: static PetscErrorCode dvd_harm_eigs_trans(dvdDashboard *d)
306: {
307:   dvdHarmonic    *data = (dvdHarmonic*)d->calcpairs_W_data;
308:   PetscInt       i,l,k;

312:   BVGetActiveColumns(d->eps->V,&l,&k);
313:   for (i=0;i<k-l;i++) {
314:     dvd_harm_backtrans(data,&d->eigr[i],&d->eigi[i]);
315:   }
316:   return(0);
317: }

319: PetscErrorCode dvd_harm_conf(dvdDashboard *d,dvdBlackboard *b,HarmType_t mode,PetscBool fixedTarget,PetscScalar t)
320: {
322:   dvdHarmonic    *dvdh;

325:   /* Set the problem to GNHEP:
326:      d->G maybe is upper triangular due to biorthogonality of V and W */
327:   d->sEP = d->sA = d->sB = 0;

329:   /* Setup the step */
330:   if (b->state >= DVD_STATE_CONF) {
331:     PetscNewLog(d->eps,&dvdh);
332:     dvdh->withTarget = fixedTarget;
333:     dvdh->mode = mode;
334:     if (fixedTarget) dvd_harm_transf(dvdh, t);
335:     d->calcpairs_W_data = dvdh;
336:     d->calcpairs_W = dvd_harm_updateW;
337:     d->calcpairs_proj_trans = dvd_harm_proj;
338:     d->calcpairs_eigs_trans = dvd_harm_eigs_trans;
339:     d->calcpairs_eig_backtrans = dvd_harm_eig_backtrans;

341:     EPSDavidsonFLAdd(&d->destroyList,dvd_harm_d);
342:   }
343:   return(0);
344: }