Line data    Source code

       1             : /*
       2             :    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
       3             :    SLEPc - Scalable Library for Eigenvalue Problem Computations
       4             :    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain
       5             : 
       6             :    This file is part of SLEPc.
       7             :    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
       8             :    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
       9             : */
      10             : 
      11             : static char help[] = "Diagonal eigenproblem. Illustrates use of shell preconditioner.\n\n"
      12             :   "The command line options are:\n"
      13             :   "  -n <n>, where <n> = number of grid subdivisions = matrix dimension.\n"
      14             :   "  -seed <s>, where <s> = seed for random number generation.\n\n";
      15             : 
      16             : #include <slepceps.h>
      17             : 
      18           0 : PetscErrorCode PCApply_User(PC pc,Vec x,Vec y)
      19             : {
      20           0 :   PetscFunctionBeginUser;
      21           0 :   PetscCall(VecCopy(x,y));
      22           0 :   PetscFunctionReturn(PETSC_SUCCESS);
      23             : }
      24             : 
      25           7 : int main(int argc,char **argv)
      26             : {
      27           7 :   Mat            A;           /* problem matrix */
      28           7 :   EPS            eps;         /* eigenproblem solver context */
      29           7 :   Vec            v0;          /* initial vector */
      30           7 :   PetscRandom    rand;
      31           7 :   PetscReal      tol=PETSC_SMALL;
      32           7 :   PetscInt       n=30,i,Istart,Iend,seed=0x12345678;
      33           7 :   ST             st;
      34           7 :   KSP            ksp;
      35           7 :   PC             pc;
      36             : 
      37           7 :   PetscFunctionBeginUser;
      38           7 :   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
      39             : 
      40           7 :   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
      41           7 :   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nDiagonal Eigenproblem, n=%" PetscInt_FMT "\n\n",n));
      42             : 
      43           7 :   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
      44           7 :   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n));
      45           7 :   PetscCall(MatSetFromOptions(A));
      46           7 :   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
      47         217 :   for (i=Istart;i<Iend;i++) PetscCall(MatSetValue(A,i,i,i+1,INSERT_VALUES));
      48           7 :   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
      49           7 :   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
      50             : 
      51             :   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      52             :                       Solve the eigensystem
      53             :      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
      54           7 :   PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
      55           7 :   PetscCall(EPSSetOperators(eps,A,NULL));
      56           7 :   PetscCall(EPSSetProblemType(eps,EPS_HEP));
      57           7 :   PetscCall(EPSSetTolerances(eps,tol,PETSC_CURRENT));
      58           7 :   PetscCall(EPSSetFromOptions(eps));
      59           7 :   PetscCall(EPSGetST(eps,&st));
      60           7 :   PetscCall(STGetKSP(st,&ksp));
      61           7 :   PetscCall(KSPGetPC(ksp,&pc));
      62           7 :   PetscCall(PCSetType(pc,PCSHELL));
      63           7 :   PetscCall(PCShellSetApply(pc,PCApply_User));
      64             : 
      65             :   /* set random initial vector */
      66           7 :   PetscCall(MatCreateVecs(A,&v0,NULL));
      67           7 :   PetscCall(PetscRandomCreate(PETSC_COMM_WORLD,&rand));
      68           7 :   PetscCall(PetscRandomSetFromOptions(rand));
      69           7 :   PetscCall(PetscOptionsGetInt(NULL,NULL,"-seed",&seed,NULL));
      70           7 :   PetscCall(PetscRandomSetSeed(rand,seed));
      71           7 :   PetscCall(PetscRandomSeed(rand));
      72           7 :   PetscCall(VecSetRandom(v0,rand));
      73           7 :   PetscCall(EPSSetInitialSpace(eps,1,&v0));
      74             :   /* call the solver */
      75           7 :   PetscCall(EPSSolve(eps));
      76             : 
      77             :   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      78             :                     Display solution and clean up
      79             :      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
      80           7 :   PetscCall(EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL));
      81           7 :   PetscCall(EPSDestroy(&eps));
      82           7 :   PetscCall(MatDestroy(&A));
      83           7 :   PetscCall(VecDestroy(&v0));
      84           7 :   PetscCall(PetscRandomDestroy(&rand));
      85           7 :   PetscCall(SlepcFinalize());
      86             :   return 0;
      87             : }
      88             : 
      89             : /*TEST
      90             : 
      91             :    testset:
      92             :       requires: !single
      93             :       output_file: output/test12_1.out
      94             :       test:
      95             :          suffix: 1
      96             :          args: -eps_type {{krylovschur subspace arnoldi gd jd}} -eps_nev 4
      97             :       test:
      98             :          suffix: 1_power
      99             :          args: -eps_type power -eps_max_it 10000 -eps_nev 4
     100             :       test:
     101             :          suffix: 1_gd2
     102             :          args: -eps_type gd -eps_gd_double_expansion -eps_nev 4
     103             : 
     104             : TEST*/