Actual source code: ex7.c

slepc-3.18.0 2022-10-01
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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[] = "Solves a generalized eigensystem Ax=kBx with matrices loaded from a file.\n"
 12:   "The command line options are:\n"
 13:   "  -f1 <filename> -f2 <filename>, PETSc binary files containing A and B.\n"
 14:   "  -evecs <filename>, output file to save computed eigenvectors.\n"
 15:   "  -ninitial <nini>, number of user-provided initial guesses.\n"
 16:   "  -finitial <filename>, binary file containing <nini> vectors.\n"
 17:   "  -nconstr <ncon>, number of user-provided constraints.\n"
 18:   "  -fconstr <filename>, binary file containing <ncon> vectors.\n\n";

 20: #include <slepceps.h>

 22: int main(int argc,char **argv)
 23: {
 24:   Mat            A,B;             /* matrices */
 25:   EPS            eps;             /* eigenproblem solver context */
 26:   ST             st;
 27:   KSP            ksp;
 28:   EPSType        type;
 29:   PetscReal      tol;
 30:   Vec            xr,xi,*Iv,*Cv;
 31:   PetscInt       nev,maxit,i,its,lits,nconv,nini=0,ncon=0;
 32:   char           filename[PETSC_MAX_PATH_LEN];
 33:   PetscViewer    viewer;
 34:   PetscBool      flg,evecs,ishermitian,terse;

 37:   SlepcInitialize(&argc,&argv,(char*)0,help);

 39:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 40:         Load the matrices that define the eigensystem, Ax=kBx
 41:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 43:   PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized eigenproblem stored in file.\n\n");
 44:   PetscOptionsGetString(NULL,NULL,"-f1",filename,sizeof(filename),&flg);

 47: #if defined(PETSC_USE_COMPLEX)
 48:   PetscPrintf(PETSC_COMM_WORLD," Reading COMPLEX matrices from binary files...\n");
 49: #else
 50:   PetscPrintf(PETSC_COMM_WORLD," Reading REAL matrices from binary files...\n");
 51: #endif
 52:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 53:   MatCreate(PETSC_COMM_WORLD,&A);
 54:   MatSetFromOptions(A);
 55:   MatLoad(A,viewer);
 56:   PetscViewerDestroy(&viewer);

 58:   PetscOptionsGetString(NULL,NULL,"-f2",filename,sizeof(filename),&flg);
 59:   if (flg) {
 60:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 61:     MatCreate(PETSC_COMM_WORLD,&B);
 62:     MatSetFromOptions(B);
 63:     MatLoad(B,viewer);
 64:     PetscViewerDestroy(&viewer);
 65:   } else {
 66:     PetscPrintf(PETSC_COMM_WORLD," Matrix B was not provided, setting B=I\n\n");
 67:     B = NULL;
 68:   }

 70:   MatCreateVecs(A,NULL,&xr);
 71:   MatCreateVecs(A,NULL,&xi);

 73:   /*
 74:      Read user constraints if available
 75:   */
 76:   PetscOptionsGetInt(NULL,NULL,"-nconstr",&ncon,&flg);
 77:   if (flg) {
 79:     PetscOptionsGetString(NULL,NULL,"-fconstr",filename,sizeof(filename),&flg);
 81:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 82:     VecDuplicateVecs(xr,ncon,&Cv);
 83:     for (i=0;i<ncon;i++) VecLoad(Cv[i],viewer);
 84:     PetscViewerDestroy(&viewer);
 85:   }

 87:   /*
 88:      Read initial guesses if available
 89:   */
 90:   PetscOptionsGetInt(NULL,NULL,"-ninitial",&nini,&flg);
 91:   if (flg) {
 93:     PetscOptionsGetString(NULL,NULL,"-finitial",filename,sizeof(filename),&flg);
 95:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 96:     VecDuplicateVecs(xr,nini,&Iv);
 97:     for (i=0;i<nini;i++) VecLoad(Iv[i],viewer);
 98:     PetscViewerDestroy(&viewer);
 99:   }

101:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
102:                 Create the eigensolver and set various options
103:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

105:   /*
106:      Create eigensolver context
107:   */
108:   EPSCreate(PETSC_COMM_WORLD,&eps);

110:   /*
111:      Set operators. In this case, it is a generalized eigenvalue problem
112:   */
113:   EPSSetOperators(eps,A,B);

115:   /*
116:      If the user provided initial guesses or constraints, pass them here
117:   */
118:   EPSSetInitialSpace(eps,nini,Iv);
119:   EPSSetDeflationSpace(eps,ncon,Cv);

121:   /*
122:      Set solver parameters at runtime
123:   */
124:   EPSSetFromOptions(eps);

126:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
127:                       Solve the eigensystem
128:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

130:   EPSSolve(eps);

132:   /*
133:      Optional: Get some information from the solver and display it
134:   */
135:   EPSGetIterationNumber(eps,&its);
136:   PetscPrintf(PETSC_COMM_WORLD," Number of iterations of the method: %" PetscInt_FMT "\n",its);
137:   EPSGetST(eps,&st);
138:   STGetKSP(st,&ksp);
139:   KSPGetTotalIterations(ksp,&lits);
140:   PetscPrintf(PETSC_COMM_WORLD," Number of linear iterations of the method: %" PetscInt_FMT "\n",lits);
141:   EPSGetType(eps,&type);
142:   PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type);
143:   EPSGetDimensions(eps,&nev,NULL,NULL);
144:   PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev);
145:   EPSGetTolerances(eps,&tol,&maxit);
146:   PetscPrintf(PETSC_COMM_WORLD," Stopping condition: tol=%.4g, maxit=%" PetscInt_FMT "\n",(double)tol,maxit);

148:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
149:                     Display solution and clean up
150:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

152:   /*
153:      Show detailed info unless -terse option is given by user
154:    */
155:   PetscOptionsHasName(NULL,NULL,"-terse",&terse);
156:   if (terse) EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
157:   else {
158:     PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
159:     EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD);
160:     EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
161:     PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
162:   }

164:   /*
165:      Save eigenvectors, if requested
166:   */
167:   PetscOptionsGetString(NULL,NULL,"-evecs",filename,sizeof(filename),&evecs);
168:   EPSGetConverged(eps,&nconv);
169:   if (nconv>0 && evecs) {
170:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_WRITE,&viewer);
171:     EPSIsHermitian(eps,&ishermitian);
172:     for (i=0;i<nconv;i++) {
173:       EPSGetEigenvector(eps,i,xr,xi);
174:       VecView(xr,viewer);
175: #if !defined(PETSC_USE_COMPLEX)
176:       if (!ishermitian) VecView(xi,viewer);
177: #endif
178:     }
179:     PetscViewerDestroy(&viewer);
180:   }

182:   /*
183:      Free work space
184:   */
185:   EPSDestroy(&eps);
186:   MatDestroy(&A);
187:   MatDestroy(&B);
188:   VecDestroy(&xr);
189:   VecDestroy(&xi);
190:   if (nini > 0) VecDestroyVecs(nini,&Iv);
191:   if (ncon > 0) VecDestroyVecs(ncon,&Cv);
192:   SlepcFinalize();
193:   return 0;
194: }

196: /*TEST

198:    test:
199:       suffix: 1
200:       args: -f1 ${SLEPC_DIR}/share/slepc/datafiles/matrices/bfw62a.petsc -f2 ${SLEPC_DIR}/share/slepc/datafiles/matrices/bfw62b.petsc -eps_nev 4 -terse
201:       requires: double !complex !defined(PETSC_USE_64BIT_INDICES)

203:    test:
204:       suffix: ciss_1
205:       args: -f1 ${DATAFILESPATH}/matrices/complex/mhd1280a.petsc -f2 ${DATAFILESPATH}/matrices/complex/mhd1280b.petsc -eps_type ciss -eps_ciss_usest 0 -eps_ciss_quadrule chebyshev -rg_type ring -rg_ring_center 0 -rg_ring_radius .49 -rg_ring_width 0.2 -rg_ring_startangle .25 -rg_ring_endangle .49 -terse -eps_max_it 1
206:       requires: double complex datafilespath !defined(PETSC_USE_64BIT_INDICES)
207:       timeoutfactor: 2

209:    test:
210:       suffix: 3  # test problem (A,A)
211:       args: -f1 ${SLEPC_DIR}/share/slepc/datafiles/matrices/bfw62a.petsc -f2 ${SLEPC_DIR}/share/slepc/datafiles/matrices/bfw62a.petsc -eps_nev 4 -terse
212:       requires: double !complex !defined(PETSC_USE_64BIT_INDICES)

214: TEST*/