Actual source code: dsnhepts.c

  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: */

 11: #include <slepc/private/dsimpl.h>
 12: #include <slepcblaslapack.h>

 14: typedef struct {
 15:   PetscScalar *wr,*wi;     /* eigenvalues of B */
 16: } DS_NHEPTS;

 18: static PetscErrorCode DSAllocate_NHEPTS(DS ds,PetscInt ld)
 19: {
 20:   DS_NHEPTS      *ctx = (DS_NHEPTS*)ds->data;

 22:   PetscFunctionBegin;
 23:   PetscCall(DSAllocateMat_Private(ds,DS_MAT_A));
 24:   PetscCall(DSAllocateMat_Private(ds,DS_MAT_B));
 25:   PetscCall(DSAllocateMat_Private(ds,DS_MAT_Q));
 26:   PetscCall(DSAllocateMat_Private(ds,DS_MAT_Z));
 27:   PetscCall(PetscFree(ds->perm));
 28:   PetscCall(PetscMalloc1(ld,&ds->perm));
 29:   PetscCall(PetscMalloc1(ld,&ctx->wr));
 30: #if !PetscDefined(USE_COMPLEX)
 31:   PetscCall(PetscMalloc1(ld,&ctx->wi));
 32: #endif
 33:   PetscFunctionReturn(PETSC_SUCCESS);
 34: }

 36: static PetscErrorCode DSView_NHEPTS(DS ds,PetscViewer viewer)
 37: {
 38:   PetscViewerFormat format;

 40:   PetscFunctionBegin;
 41:   PetscCall(PetscViewerGetFormat(viewer,&format));
 42:   if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscFunctionReturn(PETSC_SUCCESS);
 43:   PetscCall(DSViewMat(ds,viewer,DS_MAT_A));
 44:   PetscCall(DSViewMat(ds,viewer,DS_MAT_B));
 45:   if (ds->state>DS_STATE_INTERMEDIATE) {
 46:     PetscCall(DSViewMat(ds,viewer,DS_MAT_Q));
 47:     PetscCall(DSViewMat(ds,viewer,DS_MAT_Z));
 48:   }
 49:   if (ds->omat[DS_MAT_X]) PetscCall(DSViewMat(ds,viewer,DS_MAT_X));
 50:   if (ds->omat[DS_MAT_Y]) PetscCall(DSViewMat(ds,viewer,DS_MAT_Y));
 51:   PetscFunctionReturn(PETSC_SUCCESS);
 52: }

 54: static PetscErrorCode DSVectors_NHEPTS_Eigen_Some(DS ds,PetscInt *k,PetscReal *rnorm,PetscBool left)
 55: {
 56:   PetscInt          i;
 57:   PetscBLASInt      mm=1,mout,ld,n,*select,inc=1,cols=1,zero=0;
 58:   PetscScalar       sone=1.0,szero=0.0;
 59:   PetscReal         norm,done=1.0;
 60:   PetscBool         iscomplex = PETSC_FALSE;
 61:   PetscScalar       *X,*Y;
 62:   const PetscScalar *A,*Q;

 64:   PetscFunctionBegin;
 65:   PetscCall(PetscBLASIntCast(ds->n,&n));
 66:   PetscCall(PetscBLASIntCast(ds->ld,&ld));
 67:   PetscCall(DSAllocateWork_Private(ds,0,0,ld));
 68:   select = ds->iwork;
 69:   for (i=0;i<n;i++) select[i] = (PetscBLASInt)PETSC_FALSE;

 71:   /* compute k-th eigenvector Y of A */
 72:   PetscCall(MatDenseGetArrayRead(ds->omat[left?DS_MAT_B:DS_MAT_A],&A));
 73:   PetscCall(MatDenseGetArray(ds->omat[left?DS_MAT_Y:DS_MAT_X],&X));
 74:   Y = X+(*k)*ld;
 75:   select[*k] = (PetscBLASInt)PETSC_TRUE;
 76: #if !PetscDefined(USE_COMPLEX)
 77:   if ((*k)<n-1 && A[(*k)+1+(*k)*ld]!=0.0) iscomplex = PETSC_TRUE;
 78:   mm = iscomplex? 2: 1;
 79:   if (iscomplex) select[(*k)+1] = (PetscBLASInt)PETSC_TRUE;
 80:   PetscCall(DSAllocateWork_Private(ds,3*ld,0,0));
 81:   PetscCallLAPACKInfo("LAPACKtrevc",LAPACKtrevc_("R","S",select,&n,(PetscScalar*)A,&ld,Y,&ld,Y,&ld,&mm,&mout,ds->work,&info));
 82: #else
 83:   PetscCall(DSAllocateWork_Private(ds,2*ld,ld,0));
 84:   PetscCallLAPACKInfo("LAPACKtrevc",LAPACKtrevc_("R","S",select,&n,(PetscScalar*)A,&ld,Y,&ld,Y,&ld,&mm,&mout,ds->work,ds->rwork,&info));
 85: #endif
 86:   PetscCheck(mout==mm,PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Inconsistent arguments");
 87:   PetscCall(MatDenseRestoreArrayRead(ds->omat[left?DS_MAT_B:DS_MAT_A],&A));

 89:   /* accumulate and normalize eigenvectors */
 90:   if (ds->state>=DS_STATE_CONDENSED) {
 91:     PetscCall(MatDenseGetArrayRead(ds->omat[left?DS_MAT_Z:DS_MAT_Q],&Q));
 92:     PetscCall(PetscArraycpy(ds->work,Y,mout*ld));
 93:     PetscCallBLAS("BLASgemv",BLASgemv_("N",&n,&n,&sone,Q,&ld,ds->work,&inc,&szero,Y,&inc));
 94: #if !PetscDefined(USE_COMPLEX)
 95:     if (iscomplex) PetscCallBLAS("BLASgemv",BLASgemv_("N",&n,&n,&sone,Q,&ld,ds->work+ld,&inc,&szero,Y+ld,&inc));
 96: #endif
 97:     PetscCall(MatDenseRestoreArrayRead(ds->omat[left?DS_MAT_Z:DS_MAT_Q],&Q));
 98:     cols = 1;
 99:     norm = BLASnrm2_(&n,Y,&inc);
100: #if !PetscDefined(USE_COMPLEX)
101:     if (iscomplex) {
102:       norm = SlepcAbsEigenvalue(norm,BLASnrm2_(&n,Y+ld,&inc));
103:       cols = 2;
104:     }
105: #endif
106:     PetscCallLAPACKInfo("LAPACKlascl",LAPACKlascl_("G",&zero,&zero,&norm,&done,&n,&cols,Y,&ld,&info));
107:   }

109:   /* set output arguments */
110:   if (iscomplex) (*k)++;
111:   if (rnorm) {
112:     if (iscomplex) *rnorm = SlepcAbsEigenvalue(Y[n-1],Y[n-1+ld]);
113:     else *rnorm = PetscAbsScalar(Y[n-1]);
114:   }
115:   PetscCall(MatDenseRestoreArray(ds->omat[left?DS_MAT_Y:DS_MAT_X],&X));
116:   PetscFunctionReturn(PETSC_SUCCESS);
117: }

119: static PetscErrorCode DSVectors_NHEPTS_Eigen_All(DS ds,PetscBool left)
120: {
121:   PetscInt          i;
122:   PetscBLASInt      n,ld,mout,inc=1,cols,zero=0;
123:   PetscBool         iscomplex;
124:   PetscScalar       *X;
125:   const PetscScalar *A;
126:   PetscReal         norm,done=1.0;
127:   const char        *back;

129:   PetscFunctionBegin;
130:   PetscCall(PetscBLASIntCast(ds->n,&n));
131:   PetscCall(PetscBLASIntCast(ds->ld,&ld));
132:   PetscCall(MatDenseGetArrayRead(ds->omat[left?DS_MAT_B:DS_MAT_A],&A));
133:   PetscCall(MatDenseGetArrayWrite(ds->omat[left?DS_MAT_Y:DS_MAT_X],&X));
134:   if (ds->state>=DS_STATE_CONDENSED) {
135:     /* DSSolve() has been called, backtransform with matrix Q */
136:     back = "B";
137:     PetscCall(MatCopy(ds->omat[left?DS_MAT_Z:DS_MAT_Q],ds->omat[left?DS_MAT_Y:DS_MAT_X],SAME_NONZERO_PATTERN));
138:   } else back = "A";
139: #if !PetscDefined(USE_COMPLEX)
140:   PetscCall(DSAllocateWork_Private(ds,3*ld,0,0));
141:   PetscCallLAPACKInfo("LAPACKtrevc",LAPACKtrevc_("R",back,NULL,&n,(PetscScalar*)A,&ld,X,&ld,X,&ld,&n,&mout,ds->work,&info));
142: #else
143:   PetscCall(DSAllocateWork_Private(ds,2*ld,ld,0));
144:   PetscCallLAPACKInfo("LAPACKtrevc",LAPACKtrevc_("R",back,NULL,&n,(PetscScalar*)A,&ld,X,&ld,X,&ld,&n,&mout,ds->work,ds->rwork,&info));
145: #endif

147:   /* normalize eigenvectors */
148:   for (i=0;i<n;i++) {
149:     iscomplex = (i<n-1 && A[i+1+i*ld]!=0.0)? PETSC_TRUE: PETSC_FALSE;
150:     cols = 1;
151:     norm = BLASnrm2_(&n,X+i*ld,&inc);
152: #if !PetscDefined(USE_COMPLEX)
153:     if (iscomplex) {
154:       norm = SlepcAbsEigenvalue(norm,BLASnrm2_(&n,X+(i+1)*ld,&inc));
155:       cols = 2;
156:     }
157: #endif
158:     PetscCallLAPACKInfo("LAPACKlascl",LAPACKlascl_("G",&zero,&zero,&norm,&done,&n,&cols,X+i*ld,&ld,&info));
159:     if (iscomplex) i++;
160:   }
161:   PetscCall(MatDenseRestoreArrayRead(ds->omat[left?DS_MAT_B:DS_MAT_A],&A));
162:   PetscCall(MatDenseRestoreArrayWrite(ds->omat[left?DS_MAT_Y:DS_MAT_X],&X));
163:   PetscFunctionReturn(PETSC_SUCCESS);
164: }

166: static PetscErrorCode DSVectors_NHEPTS(DS ds,DSMatType mat,PetscInt *j,PetscReal *rnorm)
167: {
168:   PetscFunctionBegin;
169:   switch (mat) {
170:     case DS_MAT_X:
171:       PetscCheck(!ds->refined,PetscObjectComm((PetscObject)ds),PETSC_ERR_SUP,"Not implemented yet");
172:       if (j) PetscCall(DSVectors_NHEPTS_Eigen_Some(ds,j,rnorm,PETSC_FALSE));
173:       else PetscCall(DSVectors_NHEPTS_Eigen_All(ds,PETSC_FALSE));
174:       break;
175:     case DS_MAT_Y:
176:       PetscCheck(!ds->refined,PetscObjectComm((PetscObject)ds),PETSC_ERR_SUP,"Not implemented yet");
177:       if (j) PetscCall(DSVectors_NHEPTS_Eigen_Some(ds,j,rnorm,PETSC_TRUE));
178:       else PetscCall(DSVectors_NHEPTS_Eigen_All(ds,PETSC_TRUE));
179:       break;
180:     case DS_MAT_U:
181:     case DS_MAT_V:
182:       SETERRQ(PetscObjectComm((PetscObject)ds),PETSC_ERR_SUP,"Not implemented yet");
183:     default:
184:       SETERRQ(PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_OUTOFRANGE,"Invalid mat parameter");
185:   }
186:   PetscFunctionReturn(PETSC_SUCCESS);
187: }

189: static PetscErrorCode DSSort_NHEPTS(DS ds,PetscScalar *wr,PetscScalar *wi,PetscScalar *rr,PetscScalar *ri,PetscInt *k)
190: {
191:   DS_NHEPTS      *ctx = (DS_NHEPTS*)ds->data;
192:   PetscInt       i,j,cont,id=0,*p,*idx,*idx2;
193:   PetscReal      s,t;
194: #if PetscDefined(USE_COMPLEX)
195:   Mat            A,U;
196: #endif

198:   PetscFunctionBegin;
199:   PetscCheck(!rr || wr==rr,PetscObjectComm((PetscObject)ds),PETSC_ERR_SUP,"Not implemented yet");
200:   PetscCall(PetscMalloc3(ds->ld,&idx,ds->ld,&idx2,ds->ld,&p));
201:   PetscCall(DSSort_NHEP_Total(ds,DS_MAT_A,DS_MAT_Q,wr,wi));
202: #if PetscDefined(USE_COMPLEX)
203:   PetscCall(DSGetMat(ds,DS_MAT_B,&A));
204:   PetscCall(MatConjugate(A));
205:   PetscCall(DSRestoreMat(ds,DS_MAT_B,&A));
206:   PetscCall(DSGetMat(ds,DS_MAT_Z,&U));
207:   PetscCall(MatConjugate(U));
208:   PetscCall(DSRestoreMat(ds,DS_MAT_Z,&U));
209:   for (i=0;i<ds->n;i++) ctx->wr[i] = PetscConj(ctx->wr[i]);
210: #endif
211:   PetscCall(DSSort_NHEP_Total(ds,DS_MAT_B,DS_MAT_Z,ctx->wr,ctx->wi));
212:   /* check correct eigenvalue correspondence */
213:   cont = 0;
214:   for (i=0;i<ds->n;i++) {
215:     if (SlepcAbsEigenvalue(ctx->wr[i]-wr[i],ctx->wi[i]-wi[i])>PETSC_SQRT_MACHINE_EPSILON) {idx2[cont] = i; idx[cont++] = i;}
216:     p[i] = -1;
217:   }
218:   if (cont) {
219:     for (i=0;i<cont;i++) {
220:       t = PETSC_MAX_REAL;
221:       for (j=0;j<cont;j++) if (idx2[j]!=-1 && (s=SlepcAbsEigenvalue(ctx->wr[idx[j]]-wr[idx[i]],ctx->wi[idx[j]]-wi[idx[i]]))<t) { id = j; t = s; }
222:       p[idx[i]] = idx[id];
223:       idx2[id] = -1;
224:     }
225:     for (i=0;i<ds->n;i++) if (p[i]==-1) p[i] = i;
226:     PetscCall(DSSortWithPermutation_NHEP_Private(ds,p,DS_MAT_B,DS_MAT_Z,ctx->wr,ctx->wi));
227:   }
228: #if PetscDefined(USE_COMPLEX)
229:   PetscCall(DSGetMat(ds,DS_MAT_B,&A));
230:   PetscCall(MatConjugate(A));
231:   PetscCall(DSRestoreMat(ds,DS_MAT_B,&A));
232:   PetscCall(DSGetMat(ds,DS_MAT_Z,&U));
233:   PetscCall(MatConjugate(U));
234:   PetscCall(DSRestoreMat(ds,DS_MAT_Z,&U));
235: #endif
236:   PetscCall(PetscFree3(idx,idx2,p));
237:   PetscFunctionReturn(PETSC_SUCCESS);
238: }

240: static PetscErrorCode DSUpdateExtraRow_NHEPTS(DS ds)
241: {
242:   PetscInt          i;
243:   PetscBLASInt      n,ld,incx=1;
244:   PetscScalar       *A,*x,*y,one=1.0,zero=0.0;
245:   const PetscScalar *Q;

247:   PetscFunctionBegin;
248:   PetscCall(PetscBLASIntCast(ds->n,&n));
249:   PetscCall(PetscBLASIntCast(ds->ld,&ld));
250:   PetscCall(DSAllocateWork_Private(ds,2*ld,0,0));
251:   x = ds->work;
252:   y = ds->work+ld;
253:   PetscCall(MatDenseGetArray(ds->omat[DS_MAT_A],&A));
254:   PetscCall(MatDenseGetArrayRead(ds->omat[DS_MAT_Q],&Q));
255:   for (i=0;i<n;i++) x[i] = PetscConj(A[n+i*ld]);
256:   PetscCallBLAS("BLASgemv",BLASgemv_("C",&n,&n,&one,Q,&ld,x,&incx,&zero,y,&incx));
257:   for (i=0;i<n;i++) A[n+i*ld] = PetscConj(y[i]);
258:   PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_A],&A));
259:   PetscCall(MatDenseRestoreArrayRead(ds->omat[DS_MAT_Q],&Q));
260:   PetscCall(MatDenseGetArray(ds->omat[DS_MAT_B],&A));
261:   PetscCall(MatDenseGetArrayRead(ds->omat[DS_MAT_Z],&Q));
262:   for (i=0;i<n;i++) x[i] = PetscConj(A[n+i*ld]);
263:   PetscCallBLAS("BLASgemv",BLASgemv_("C",&n,&n,&one,Q,&ld,x,&incx,&zero,y,&incx));
264:   for (i=0;i<n;i++) A[n+i*ld] = PetscConj(y[i]);
265:   PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_B],&A));
266:   PetscCall(MatDenseRestoreArrayRead(ds->omat[DS_MAT_Z],&Q));
267:   ds->k = n;
268:   PetscFunctionReturn(PETSC_SUCCESS);
269: }

271: static PetscErrorCode DSSolve_NHEPTS(DS ds,PetscScalar *wr,PetscScalar *wi)
272: {
273:   DS_NHEPTS      *ctx = (DS_NHEPTS*)ds->data;

275:   PetscFunctionBegin;
276: #if !PetscDefined(USE_COMPLEX)
277:   PetscAssertPointer(wi,3);
278: #endif
279:   PetscCall(DSSolve_NHEP_Private(ds,DS_MAT_A,DS_MAT_Q,wr,wi));
280:   PetscCall(DSSolve_NHEP_Private(ds,DS_MAT_B,DS_MAT_Z,ctx->wr,ctx->wi));
281:   PetscFunctionReturn(PETSC_SUCCESS);
282: }

284: #if !PetscDefined(HAVE_MPIUNI)
285: static PetscErrorCode DSSynchronize_NHEPTS(DS ds,PetscScalar eigr[],PetscScalar eigi[])
286: {
287:   PetscInt       ld=ds->ld,l=ds->l,k;
288:   PetscMPIInt    n,rank,off=0,size,ldn;
289:   DS_NHEPTS      *ctx = (DS_NHEPTS*)ds->data;
290:   PetscScalar    *A,*B,*Q,*Z;

292:   PetscFunctionBegin;
293:   k = 2*(ds->n-l)*ld;
294:   if (ds->state>DS_STATE_RAW) k += 2*(ds->n-l)*ld;
295:   if (eigr) k += ds->n-l;
296:   if (eigi) k += ds->n-l;
297:   if (ctx->wr) k += ds->n-l;
298:   if (ctx->wi) k += ds->n-l;
299:   PetscCall(DSAllocateWork_Private(ds,k,0,0));
300:   PetscCall(PetscMPIIntCast(k*sizeof(PetscScalar),&size));
301:   PetscCall(PetscMPIIntCast(ds->n-l,&n));
302:   PetscCall(PetscMPIIntCast(ld*(ds->n-l),&ldn));
303:   PetscCall(MatDenseGetArray(ds->omat[DS_MAT_A],&A));
304:   PetscCall(MatDenseGetArray(ds->omat[DS_MAT_B],&B));
305:   if (ds->state>DS_STATE_RAW) {
306:     PetscCall(MatDenseGetArray(ds->omat[DS_MAT_Q],&Q));
307:     PetscCall(MatDenseGetArray(ds->omat[DS_MAT_Z],&Z));
308:   }
309:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)ds),&rank));
310:   if (!rank) {
311:     PetscCallMPI(MPI_Pack(A+l*ld,ldn,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
312:     PetscCallMPI(MPI_Pack(B+l*ld,ldn,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
313:     if (ds->state>DS_STATE_RAW) {
314:       PetscCallMPI(MPI_Pack(Q+l*ld,ldn,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
315:       PetscCallMPI(MPI_Pack(Z+l*ld,ldn,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
316:     }
317:     if (eigr) PetscCallMPI(MPI_Pack(eigr+l,n,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
318: #if !PetscDefined(USE_COMPLEX)
319:     if (eigi) PetscCallMPI(MPI_Pack(eigi+l,n,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
320: #endif
321:     if (ctx->wr) PetscCallMPI(MPI_Pack(ctx->wr+l,n,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
322:     if (ctx->wi) PetscCallMPI(MPI_Pack(ctx->wi+l,n,MPIU_SCALAR,ds->work,size,&off,PetscObjectComm((PetscObject)ds)));
323:   }
324:   PetscCallMPI(MPI_Bcast(ds->work,size,MPI_BYTE,0,PetscObjectComm((PetscObject)ds)));
325:   if (rank) {
326:     PetscCallMPI(MPI_Unpack(ds->work,size,&off,A+l*ld,ldn,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
327:     PetscCallMPI(MPI_Unpack(ds->work,size,&off,B+l*ld,ldn,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
328:     if (ds->state>DS_STATE_RAW) {
329:       PetscCallMPI(MPI_Unpack(ds->work,size,&off,Q+l*ld,ldn,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
330:       PetscCallMPI(MPI_Unpack(ds->work,size,&off,Z+l*ld,ldn,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
331:     }
332:     if (eigr) PetscCallMPI(MPI_Unpack(ds->work,size,&off,eigr+l,n,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
333: #if !PetscDefined(USE_COMPLEX)
334:     if (eigi) PetscCallMPI(MPI_Unpack(ds->work,size,&off,eigi+l,n,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
335: #endif
336:     if (ctx->wr) PetscCallMPI(MPI_Unpack(ds->work,size,&off,ctx->wr+l,n,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
337:     if (ctx->wi) PetscCallMPI(MPI_Unpack(ds->work,size,&off,ctx->wi+l,n,MPIU_SCALAR,PetscObjectComm((PetscObject)ds)));
338:   }
339:   PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_A],&A));
340:   PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_B],&B));
341:   if (ds->state>DS_STATE_RAW) {
342:     PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_Q],&Q));
343:     PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_Z],&Z));
344:   }
345:   PetscFunctionReturn(PETSC_SUCCESS);
346: }
347: #endif

349: static PetscErrorCode DSGetTruncateSize_NHEPTS(DS ds,PetscInt l,PetscInt n,PetscInt *k)
350: {
351: #if !PetscDefined(USE_COMPLEX)
352:   const PetscScalar *A,*B;
353: #endif

355:   PetscFunctionBegin;
356: #if !PetscDefined(USE_COMPLEX)
357:   PetscCall(MatDenseGetArrayRead(ds->omat[DS_MAT_A],&A));
358:   PetscCall(MatDenseGetArrayRead(ds->omat[DS_MAT_B],&B));
359:   if (A[l+(*k)+(l+(*k)-1)*ds->ld] != 0.0 || B[l+(*k)+(l+(*k)-1)*ds->ld] != 0.0) {
360:     if (l+(*k)<n-1) (*k)++;
361:     else (*k)--;
362:   }
363:   PetscCall(MatDenseRestoreArrayRead(ds->omat[DS_MAT_A],&A));
364:   PetscCall(MatDenseRestoreArrayRead(ds->omat[DS_MAT_B],&B));
365: #endif
366:   PetscFunctionReturn(PETSC_SUCCESS);
367: }

369: static PetscErrorCode DSTruncate_NHEPTS(DS ds,PetscInt n,PetscBool trim)
370: {
371:   PetscInt    i,ld=ds->ld,l=ds->l;
372:   PetscScalar *A,*B;

374:   PetscFunctionBegin;
375:   PetscCall(MatDenseGetArray(ds->omat[DS_MAT_A],&A));
376:   PetscCall(MatDenseGetArray(ds->omat[DS_MAT_B],&B));
377: #if PetscDefined(USE_DEBUG)
378:   /* make sure diagonal 2x2 block is not broken */
379:   PetscCheck(ds->state<DS_STATE_CONDENSED || n==0 || n==ds->n || A[n+(n-1)*ld]==0.0 || B[n+(n-1)*ld]==0.0,PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"The given size would break a 2x2 block, call DSGetTruncateSize() first");
380: #endif
381:   if (trim) {
382:     if (ds->extrarow) {   /* clean extra row */
383:       for (i=l;i<ds->n;i++) { A[ds->n+i*ld] = 0.0; B[ds->n+i*ld] = 0.0; }
384:     }
385:     ds->l = 0;
386:     ds->k = 0;
387:     ds->n = n;
388:     ds->t = ds->n;   /* truncated length equal to the new dimension */
389:   } else {
390:     if (ds->extrarow && ds->k==ds->n) {
391:       /* copy entries of extra row to the new position, then clean last row */
392:       for (i=l;i<n;i++) { A[n+i*ld] = A[ds->n+i*ld]; B[n+i*ld] = B[ds->n+i*ld]; }
393:       for (i=l;i<ds->n;i++) { A[ds->n+i*ld] = 0.0; B[ds->n+i*ld] = 0.0; }
394:     }
395:     ds->k = ds->extrarow? n: 0;
396:     ds->t = ds->n;   /* truncated length equal to previous dimension */
397:     ds->n = n;
398:   }
399:   PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_A],&A));
400:   PetscCall(MatDenseRestoreArray(ds->omat[DS_MAT_B],&B));
401:   PetscFunctionReturn(PETSC_SUCCESS);
402: }

404: static PetscErrorCode DSDestroy_NHEPTS(DS ds)
405: {
406:   DS_NHEPTS      *ctx = (DS_NHEPTS*)ds->data;

408:   PetscFunctionBegin;
409:   PetscCall(PetscFree(ctx->wr));
410:   PetscCall(PetscFree(ctx->wi));
411:   PetscCall(PetscFree(ds->data));
412:   PetscFunctionReturn(PETSC_SUCCESS);
413: }

415: static PetscErrorCode DSMatGetSize_NHEPTS(DS ds,DSMatType t,PetscInt *rows,PetscInt *cols)
416: {
417:   PetscFunctionBegin;
418:   *rows = ((t==DS_MAT_A || t==DS_MAT_B) && ds->extrarow)? ds->n+1: ds->n;
419:   *cols = ds->n;
420:   PetscFunctionReturn(PETSC_SUCCESS);
421: }

423: /*MC
424:    DSNHEPTS - Dense Non-Hermitian Eigenvalue Problem (special variant intended
425:    for two-sided Krylov solvers).

427:    Notes:
428:    Two related problems are solved, $AX = X\Lambda$ and $BY = Y\Lambda^*$, where $A$ and
429:    $B$ are supposed to come from the Arnoldi factorizations of a certain matrix and its
430:    (conjugate) transpose, respectively. Hence, in exact arithmetic the columns of $Y$
431:    are equal to the left eigenvectors of $A$. $\Lambda$ is a diagonal matrix whose diagonal
432:    elements are the arguments of `DSSolve()`. After solve, $A$ is overwritten with the
433:    upper quasi-triangular matrix $T$ of the (real) Schur form, $AQ = QT$, and similarly
434:    another (real) Schur relation is computed, $BZ = ZS$, overwriting $B$.

436:    In the intermediate state $A$ and $B$ are reduced to upper Hessenberg form.

438:    When left eigenvectors `DS_MAT_Y` are requested, right eigenvectors of $B$ are returned,
439:    while `DS_MAT_X` contains right eigenvectors of $A$.

441:    Used DS matrices:
442: +  `DS_MAT_A` - first problem matrix obtained from Arnoldi
443: .  `DS_MAT_B` - second problem matrix obtained from Arnoldi on the transpose
444: .  `DS_MAT_Q` - orthogonal/unitary transformation that reduces $A$ to Hessenberg form
445:    (intermediate step) or matrix of orthogonal Schur vectors of $A$
446: -  `DS_MAT_Z` - orthogonal/unitary transformation that reduces $B$ to Hessenberg form
447:    (intermediate step) or matrix of orthogonal Schur vectors of $B$

449:    Implemented methods:
450: .  0 - Implicit QR (`_hseqr`)

452:    Level: beginner

454: .seealso: [](sec:ds), `DSCreate()`, `DSSetType()`, `DSType`
455: M*/
456: SLEPC_EXTERN PetscErrorCode DSCreate_NHEPTS(DS ds)
457: {
458:   DS_NHEPTS      *ctx;

460:   PetscFunctionBegin;
461:   PetscCall(PetscNew(&ctx));
462:   ds->data = (void*)ctx;

464:   ds->ops->allocate        = DSAllocate_NHEPTS;
465:   ds->ops->view            = DSView_NHEPTS;
466:   ds->ops->vectors         = DSVectors_NHEPTS;
467:   ds->ops->solve[0]        = DSSolve_NHEPTS;
468:   ds->ops->sort            = DSSort_NHEPTS;
469: #if !PetscDefined(HAVE_MPIUNI)
470:   ds->ops->synchronize     = DSSynchronize_NHEPTS;
471: #endif
472:   ds->ops->gettruncatesize = DSGetTruncateSize_NHEPTS;
473:   ds->ops->truncate        = DSTruncate_NHEPTS;
474:   ds->ops->update          = DSUpdateExtraRow_NHEPTS;
475:   ds->ops->destroy         = DSDestroy_NHEPTS;
476:   ds->ops->matgetsize      = DSMatGetSize_NHEPTS;
477:   PetscFunctionReturn(PETSC_SUCCESS);
478: }