Actual source code: test45.c

slepc-3.23.1 2025-05-01
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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[] = "Test interface to external package ChASE.\n\n"
 12:   "This is based on ex3.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;           /* matrix */
 21:   EPS        eps;         /* eigenproblem solver context */
 22:   PetscInt   N,n=35,m,Istart,Iend,II,i,j,deg;
 23:   PetscBool  opt,flag;

 25:   PetscFunctionBeginUser;
 26:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));

 28:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
 29:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag));
 30:   if (!flag) m=n;
 31:   N = n*m;
 32:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nStandard eigenproblem with ChASE, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m));

 34:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 35:          Compute the matrix that defines the eigensystem, Ax=kx
 36:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 38:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
 39:   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N));
 40:   PetscCall(MatSetFromOptions(A));

 42:   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
 43:   for (II=Istart;II<Iend;II++) {
 44:     i = II/n; j = II-i*n;
 45:     if (i>0) PetscCall(MatSetValue(A,II,II-n,-1.0,INSERT_VALUES));
 46:     if (i<m-1) PetscCall(MatSetValue(A,II,II+n,-1.0,INSERT_VALUES));
 47:     if (j>0) PetscCall(MatSetValue(A,II,II-1,-1.0,INSERT_VALUES));
 48:     if (j<n-1) PetscCall(MatSetValue(A,II,II+1,-1.0,INSERT_VALUES));
 49:     PetscCall(MatSetValue(A,II,II,4.0,INSERT_VALUES));
 50:   }

 52:   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
 53:   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));

 55:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 56:                 Create the eigensolver and set various options
 57:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 59:   PetscCall(EPSCreate(PETSC_COMM_WORLD,&eps));
 60:   PetscCall(EPSSetOperators(eps,A,NULL));
 61:   PetscCall(EPSSetProblemType(eps,EPS_HEP));
 62:   PetscCall(EPSSetType(eps,EPSCHASE));
 63:   PetscCall(EPSSetDimensions(eps,6,PETSC_DETERMINE,PETSC_DETERMINE));
 64:   PetscCall(EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL));
 65:   deg = 20;
 66:   opt = PETSC_TRUE;
 67:   PetscCall(EPSCHASESetDegree(eps,deg,opt));
 68:   PetscCall(EPSSetFromOptions(eps));

 70:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 71:                  Compute eigenvalues and display info
 72:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 74:   PetscCall(EPSSolve(eps));
 75:   PetscCall(EPSCHASEGetDegree(eps,&deg,&opt));
 76:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," ChASE: using degree %" PetscInt_FMT ", optimization %s\n",deg,PetscBools[opt]));

 78:   PetscCall(EPSErrorView(eps,EPS_ERROR_ABSOLUTE,NULL));

 80:   PetscCall(EPSDestroy(&eps));
 81:   PetscCall(MatDestroy(&A));
 82:   PetscCall(SlepcFinalize());
 83:   return 0;
 84: }

 86: /*TEST

 88:    build:
 89:       requires: chase

 91:    testset:
 92:       requires: chase
 93:       output_file: output/test45_1.out
 94:       test:
 95:          suffix: 1
 96:       test:
 97:          suffix: 2
 98:          args: -mat_scalapack_grid_height 2
 99:          nsize: 2

101: TEST*/