Actual source code: ex7.c

slepc-3.21.1 2024-04-26
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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;

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

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

 43:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized eigenproblem stored in file.\n\n"));
 44:   PetscCall(PetscOptionsGetString(NULL,NULL,"-f1",filename,sizeof(filename),&flg));
 45:   PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Must indicate a file name for matrix A with the -f1 option");

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

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

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

 73:   /*
 74:      Read user constraints if available
 75:   */
 76:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-nconstr",&ncon,&flg));
 77:   if (flg) {
 78:     PetscCheck(ncon>0,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"The number of constraints must be >0");
 79:     PetscCall(PetscOptionsGetString(NULL,NULL,"-fconstr",filename,sizeof(filename),&flg));
 80:     PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Must specify the name of the file storing the constraints");
 81:     PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer));
 82:     PetscCall(VecDuplicateVecs(xr,ncon,&Cv));
 83:     for (i=0;i<ncon;i++) PetscCall(VecLoad(Cv[i],viewer));
 84:     PetscCall(PetscViewerDestroy(&viewer));
 85:   }

 87:   /*
 88:      Read initial guesses if available
 89:   */
 90:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-ninitial",&nini,&flg));
 91:   if (flg) {
 92:     PetscCheck(nini>0,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"The number of initial vectors must be >0");
 93:     PetscCall(PetscOptionsGetString(NULL,NULL,"-finitial",filename,sizeof(filename),&flg));
 94:     PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Must specify the name of the file containing the initial vectors");
 95:     PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer));
 96:     PetscCall(VecDuplicateVecs(xr,nini,&Iv));
 97:     for (i=0;i<nini;i++) PetscCall(VecLoad(Iv[i],viewer));
 98:     PetscCall(PetscViewerDestroy(&viewer));
 99:   }

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

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

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

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

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

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

130:   PetscCall(EPSSolve(eps));

132:   /*
133:      Optional: Get some information from the solver and display it
134:   */
135:   PetscCall(EPSGetIterationNumber(eps,&its));
136:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of iterations of the method: %" PetscInt_FMT "\n",its));
137:   PetscCall(EPSGetST(eps,&st));
138:   PetscCall(STGetKSP(st,&ksp));
139:   PetscCall(KSPGetTotalIterations(ksp,&lits));
140:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of linear iterations of the method: %" PetscInt_FMT "\n",lits));
141:   PetscCall(EPSGetType(eps,&type));
142:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type));
143:   PetscCall(EPSGetDimensions(eps,&nev,NULL,NULL));
144:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev));
145:   PetscCall(EPSGetTolerances(eps,&tol,&maxit));
146:   PetscCall(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:   PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
156:   if (terse) PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
157:   else {
158:     PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
159:     PetscCall(EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD));
160:     PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD));
161:     PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
162:   }

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

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