Actual source code: ex4.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: */

 11: static char help[] = "Solves a standard eigensystem Ax=kx with the matrix loaded from a file.\n"
 12:   "This example works for both real and complex numbers.\n\n"
 13:   "The command line options are:\n"
 14:   "  -file <filename>, where <filename> = matrix file in PETSc binary form.\n\n";

 16: #include <slepceps.h>

 18: int main(int argc,char **argv)
 19: {
 20:   Mat            A;               /* operator matrix */
 21:   EPS            eps;             /* eigenproblem solver context */
 22:   EPSType        type;
 23:   PetscReal      tol;
 24:   PetscInt       nev,maxit,its;
 25:   char           filename[PETSC_MAX_PATH_LEN];
 26:   PetscViewer    viewer;
 27:   PetscBool      flg,terse;

 30:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;

 32:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 33:         Load the operator matrix that defines the eigensystem, Ax=kx
 34:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 36:   PetscPrintf(PETSC_COMM_WORLD,"\nEigenproblem stored in file.\n\n");
 37:   PetscOptionsGetString(NULL,NULL,"-file",filename,PETSC_MAX_PATH_LEN,&flg);
 38:   if (!flg) SETERRQ(PETSC_COMM_WORLD,1,"Must indicate a file name with the -file option");

 40: #if defined(PETSC_USE_COMPLEX)
 41:   PetscPrintf(PETSC_COMM_WORLD," Reading COMPLEX matrix from a binary file...\n");
 42: #else
 43:   PetscPrintf(PETSC_COMM_WORLD," Reading REAL matrix from a binary file...\n");
 44: #endif
 45:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 46:   MatCreate(PETSC_COMM_WORLD,&A);
 47:   MatSetFromOptions(A);
 48:   MatLoad(A,viewer);
 49:   PetscViewerDestroy(&viewer);

 51:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 52:                 Create the eigensolver and set various options
 53:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 55:   /*
 56:      Create eigensolver context
 57:   */
 58:   EPSCreate(PETSC_COMM_WORLD,&eps);

 60:   /*
 61:      Set operators. In this case, it is a standard eigenvalue problem
 62:   */
 63:   EPSSetOperators(eps,A,NULL);

 65:   /*
 66:      Set solver parameters at runtime
 67:   */
 68:   EPSSetFromOptions(eps);

 70:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 71:                       Solve the eigensystem
 72:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 74:   EPSSolve(eps);
 75:   EPSGetIterationNumber(eps,&its);
 76:   PetscPrintf(PETSC_COMM_WORLD," Number of iterations of the method: %D\n",its);

 78:   /*
 79:      Optional: Get some information from the solver and display it
 80:   */
 81:   EPSGetType(eps,&type);
 82:   PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type);
 83:   EPSGetDimensions(eps,&nev,NULL,NULL);
 84:   PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %D\n",nev);
 85:   EPSGetTolerances(eps,&tol,&maxit);
 86:   PetscPrintf(PETSC_COMM_WORLD," Stopping condition: tol=%.4g, maxit=%D\n",(double)tol,maxit);

 88:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 89:                     Display solution and clean up
 90:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 92:   /* show detailed info unless -terse option is given by user */
 93:   PetscOptionsHasName(NULL,NULL,"-terse",&terse);
 94:   if (terse) {
 95:     EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
 96:   } else {
 97:     PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
 98:     EPSReasonView(eps,PETSC_VIEWER_STDOUT_WORLD);
 99:     EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
100:     PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
101:   }
102:   EPSDestroy(&eps);
103:   MatDestroy(&A);
104:   SlepcFinalize();
105:   return ierr;
106: }

108: /*TEST

110:    test:
111:       suffix: 1
112:       args: -file ${SLEPC_DIR}/share/slepc/datafiles/matrices/rdb200.petsc -eps_nev 4 -terse
113:       requires: double !complex !define(PETSC_USE_64BIT_INDICES)

115:    test:
116:       suffix: ciss_1
117:       args: -file ${DATAFILESPATH}/matrices/complex/qc324.petsc -eps_type ciss -rg_type ellipse -rg_ellipse_center -.012-.08i -rg_ellipse_radius .05 -terse
118:       requires: complex datafilespath

120: TEST*/