Actual source code: test17.c

slepc-3.17.0 2022-03-31
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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: */

 11: static char help[] = "Test interface functions of spectrum-slicing Krylov-Schur.\n\n"
 12:   "This is based on ex12.c. The command line options are:\n"
 13:   "  -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
 14:   "  -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";

 16: #include <slepceps.h>

 18: int main(int argc,char **argv)
 19: {
 20:   Mat            A,B;         /* matrices */
 21:   Mat            As,Bs;       /* matrices distributed in subcommunicators */
 22:   Mat            Au;          /* matrix used to modify A on subcommunicators */
 23:   EPS            eps;         /* eigenproblem solver context */
 24:   ST             st;          /* spectral transformation context */
 25:   KSP            ksp;
 26:   PC             pc;
 27:   Vec            v;
 28:   PetscMPIInt    size,rank;
 29:   PetscInt       N,n=35,m,Istart,Iend,II,nev,ncv,mpd,i,j,k,*inertias,npart,nval,nloc,nlocs,mlocs;
 30:   PetscBool      flag,showinertia=PETSC_TRUE,lock,detect;
 31:   PetscReal      int0,int1,*shifts,keep,*subint,*evals;
 32:   PetscScalar    lambda;
 33:   char           vlist[4000];

 35:   SlepcInitialize(&argc,&argv,(char*)0,help);
 36:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
 37:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);

 39:   PetscOptionsGetBool(NULL,NULL,"-showinertia",&showinertia,NULL);
 40:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 41:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
 42:   if (!flag) m=n;
 43:   N = n*m;
 44:   PetscPrintf(PETSC_COMM_WORLD,"\nSpectrum-slicing test, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m);

 46:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 47:      Compute the matrices that define the eigensystem, Ax=kBx
 48:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 50:   MatCreate(PETSC_COMM_WORLD,&A);
 51:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
 52:   MatSetFromOptions(A);
 53:   MatSetUp(A);

 55:   MatCreate(PETSC_COMM_WORLD,&B);
 56:   MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,N,N);
 57:   MatSetFromOptions(B);
 58:   MatSetUp(B);

 60:   MatGetOwnershipRange(A,&Istart,&Iend);
 61:   for (II=Istart;II<Iend;II++) {
 62:     i = II/n; j = II-i*n;
 63:     if (i>0) MatSetValue(A,II,II-n,-1.0,INSERT_VALUES);
 64:     if (i<m-1) MatSetValue(A,II,II+n,-1.0,INSERT_VALUES);
 65:     if (j>0) MatSetValue(A,II,II-1,-1.0,INSERT_VALUES);
 66:     if (j<n-1) MatSetValue(A,II,II+1,-1.0,INSERT_VALUES);
 67:     MatSetValue(A,II,II,4.0,INSERT_VALUES);
 68:     MatSetValue(B,II,II,2.0,INSERT_VALUES);
 69:   }
 70:   if (Istart==0) {
 71:     MatSetValue(B,0,0,6.0,INSERT_VALUES);
 72:     MatSetValue(B,0,1,-1.0,INSERT_VALUES);
 73:     MatSetValue(B,1,0,-1.0,INSERT_VALUES);
 74:     MatSetValue(B,1,1,1.0,INSERT_VALUES);
 75:   }

 77:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 78:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
 79:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
 80:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);

 82:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 83:                 Create the eigensolver and set various options
 84:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 86:   EPSCreate(PETSC_COMM_WORLD,&eps);
 87:   EPSSetOperators(eps,A,B);
 88:   EPSSetProblemType(eps,EPS_GHEP);
 89:   EPSSetType(eps,EPSKRYLOVSCHUR);

 91:   /*
 92:      Set interval and other settings for spectrum slicing
 93:   */
 94:   EPSSetWhichEigenpairs(eps,EPS_ALL);
 95:   int0 = 1.1; int1 = 1.3;
 96:   EPSSetInterval(eps,int0,int1);
 97:   EPSGetST(eps,&st);
 98:   STSetType(st,STSINVERT);
 99:   if (size>1) EPSKrylovSchurSetPartitions(eps,size);
100:   EPSKrylovSchurGetKSP(eps,&ksp);
101:   KSPGetPC(ksp,&pc);
102:   KSPSetType(ksp,KSPPREONLY);
103:   PCSetType(pc,PCCHOLESKY);

105:   /*
106:      Test interface functions of Krylov-Schur solver
107:   */
108:   EPSKrylovSchurGetRestart(eps,&keep);
109:   PetscPrintf(PETSC_COMM_WORLD," Restart parameter before changing = %g",(double)keep);
110:   EPSKrylovSchurSetRestart(eps,0.4);
111:   EPSKrylovSchurGetRestart(eps,&keep);
112:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %g\n",(double)keep);

114:   EPSKrylovSchurGetDetectZeros(eps,&detect);
115:   PetscPrintf(PETSC_COMM_WORLD," Detect zeros before changing = %d",(int)detect);
116:   EPSKrylovSchurSetDetectZeros(eps,PETSC_TRUE);
117:   EPSKrylovSchurGetDetectZeros(eps,&detect);
118:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)detect);

120:   EPSKrylovSchurGetLocking(eps,&lock);
121:   PetscPrintf(PETSC_COMM_WORLD," Locking flag before changing = %d",(int)lock);
122:   EPSKrylovSchurSetLocking(eps,PETSC_FALSE);
123:   EPSKrylovSchurGetLocking(eps,&lock);
124:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d\n",(int)lock);

126:   EPSKrylovSchurGetDimensions(eps,&nev,&ncv,&mpd);
127:   PetscPrintf(PETSC_COMM_WORLD," Sub-solve dimensions before changing = [%" PetscInt_FMT ",%" PetscInt_FMT ",%" PetscInt_FMT "]",nev,ncv,mpd);
128:   EPSKrylovSchurSetDimensions(eps,30,60,60);
129:   EPSKrylovSchurGetDimensions(eps,&nev,&ncv,&mpd);
130:   PetscPrintf(PETSC_COMM_WORLD," ... changed to [%" PetscInt_FMT ",%" PetscInt_FMT ",%" PetscInt_FMT "]\n",nev,ncv,mpd);

132:   if (size>1) {
133:     EPSKrylovSchurGetPartitions(eps,&npart);
134:     PetscPrintf(PETSC_COMM_WORLD," Using %" PetscInt_FMT " partitions\n",npart);

136:     PetscMalloc1(npart+1,&subint);
137:     subint[0] = int0;
138:     subint[npart] = int1;
139:     for (i=1;i<npart;i++) subint[i] = int0+i*(int1-int0)/npart;
140:     EPSKrylovSchurSetSubintervals(eps,subint);
141:     PetscFree(subint);
142:     EPSKrylovSchurGetSubintervals(eps,&subint);
143:     PetscPrintf(PETSC_COMM_WORLD," Using sub-interval separations = ");
144:     for (i=1;i<npart;i++) PetscPrintf(PETSC_COMM_WORLD," %g",(double)subint[i]);
145:     PetscFree(subint);
146:     PetscPrintf(PETSC_COMM_WORLD,"\n");
147:   }

149:   EPSSetFromOptions(eps);

151:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
152:            Compute all eigenvalues in interval and display info
153:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

155:   EPSSetUp(eps);
156:   EPSKrylovSchurGetInertias(eps,&k,&shifts,&inertias);
157:   PetscPrintf(PETSC_COMM_WORLD," Inertias after EPSSetUp:\n");
158:   for (i=0;i<k;i++) PetscPrintf(PETSC_COMM_WORLD," .. %g (%" PetscInt_FMT ")\n",(double)shifts[i],inertias[i]);
159:   PetscFree(shifts);
160:   PetscFree(inertias);

162:   EPSSolve(eps);
163:   EPSGetDimensions(eps,&nev,NULL,NULL);
164:   EPSGetInterval(eps,&int0,&int1);
165:   PetscPrintf(PETSC_COMM_WORLD," Found %" PetscInt_FMT " eigenvalues in interval [%g,%g]\n",nev,(double)int0,(double)int1);

167:   if (showinertia) {
168:     EPSKrylovSchurGetInertias(eps,&k,&shifts,&inertias);
169:     PetscPrintf(PETSC_COMM_WORLD," Used %" PetscInt_FMT " shifts (inertia):\n",k);
170:     for (i=0;i<k;i++) PetscPrintf(PETSC_COMM_WORLD," .. %g (%" PetscInt_FMT ")\n",(double)shifts[i],inertias[i]);
171:     PetscFree(shifts);
172:     PetscFree(inertias);
173:   }

175:   EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);

177:   if (size>1) {
178:     EPSKrylovSchurGetSubcommInfo(eps,&k,&nval,&v);
179:     PetscMalloc1(nval,&evals);
180:     for (i=0;i<nval;i++) {
181:       EPSKrylovSchurGetSubcommPairs(eps,i,&lambda,v);
182:       evals[i] = PetscRealPart(lambda);
183:     }
184:     PetscFormatRealArray(vlist,sizeof(vlist),"%f",nval,evals);
185:     PetscSynchronizedPrintf(PETSC_COMM_WORLD," Process %d has worked in sub-interval %" PetscInt_FMT ", containing %" PetscInt_FMT " eigenvalues: %s\n",(int)rank,k,nval,vlist);
186:     PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT);
187:     VecDestroy(&v);
188:     PetscFree(evals);

190:     EPSKrylovSchurGetSubcommMats(eps,&As,&Bs);
191:     MatGetLocalSize(A,&nloc,NULL);
192:     MatGetLocalSize(As,&nlocs,&mlocs);
193:     PetscSynchronizedPrintf(PETSC_COMM_WORLD," Process %d owns %" PetscInt_FMT " rows of the global matrices, and %" PetscInt_FMT " rows in the subcommunicator\n",(int)rank,nloc,nlocs);
194:     PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT);

196:     /* modify A on subcommunicators */
197:     MatCreate(PetscObjectComm((PetscObject)As),&Au);
198:     MatSetSizes(Au,nlocs,mlocs,N,N);
199:     MatSetFromOptions(Au);
200:     MatSetUp(Au);
201:     MatGetOwnershipRange(Au,&Istart,&Iend);
202:     for (II=Istart;II<Iend;II++) MatSetValue(Au,II,II,0.5,INSERT_VALUES);
203:     MatAssemblyBegin(Au,MAT_FINAL_ASSEMBLY);
204:     MatAssemblyEnd(Au,MAT_FINAL_ASSEMBLY);
205:     PetscPrintf(PETSC_COMM_WORLD," Updating internal matrices\n");
206:     EPSKrylovSchurUpdateSubcommMats(eps,1.1,-5.0,Au,1.0,0.0,NULL,DIFFERENT_NONZERO_PATTERN,PETSC_TRUE);
207:     MatDestroy(&Au);
208:     EPSSolve(eps);
209:     EPSGetDimensions(eps,&nev,NULL,NULL);
210:     EPSGetInterval(eps,&int0,&int1);
211:     PetscPrintf(PETSC_COMM_WORLD," After update, found %" PetscInt_FMT " eigenvalues in interval [%g,%g]\n",nev,(double)int0,(double)int1);
212:   }
213:   EPSDestroy(&eps);
214:   MatDestroy(&A);
215:   MatDestroy(&B);
216:   SlepcFinalize();
217:   return 0;
218: }

220: /*TEST

222:    test:
223:       suffix: 1
224:       nsize: 2
225:       args: -showinertia 0 -log_exclude eps,st,rg,bv,ds
226:       requires: !single

228:    test:
229:       suffix: 2
230:       nsize: 1
231:       args: -showinertia 0 -log_exclude eps,st,rg,bv,ds
232:       requires: !single

234: TEST*/