Actual source code: test34.c

slepc-3.16.3 2022-04-11
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2021, 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 PRIMME.\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:   ST              st;          /* spectral transformation context */
 23:   KSP             ksp;
 24:   PC              pc;
 25:   PetscInt        N,n=35,m,Istart,Iend,II,i,j,bs;
 26:   PetscBool       flag;
 27:   EPSPRIMMEMethod meth;
 28:   PetscErrorCode  ierr;

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

 32:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 33:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
 34:   if (!flag) m=n;
 35:   N = n*m;
 36:   PetscPrintf(PETSC_COMM_WORLD,"\nStandard eigenproblem with PRIMME, N=%D (%Dx%D grid)\n\n",N,n,m);

 38:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 39:          Compute the matrices that define the eigensystem, Ax=kBx
 40:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 42:   MatCreate(PETSC_COMM_WORLD,&A);
 43:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
 44:   MatSetFromOptions(A);
 45:   MatSetUp(A);

 47:   MatGetOwnershipRange(A,&Istart,&Iend);
 48:   for (II=Istart;II<Iend;II++) {
 49:     i = II/n; j = II-i*n;
 50:     if (i>0) { MatSetValue(A,II,II-n,-1.0,INSERT_VALUES); }
 51:     if (i<m-1) { MatSetValue(A,II,II+n,-1.0,INSERT_VALUES); }
 52:     if (j>0) { MatSetValue(A,II,II-1,-1.0,INSERT_VALUES); }
 53:     if (j<n-1) { MatSetValue(A,II,II+1,-1.0,INSERT_VALUES); }
 54:     MatSetValue(A,II,II,4.0,INSERT_VALUES);
 55:   }

 57:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 58:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 60:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 61:                 Create the eigensolver and set various options
 62:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 64:   EPSCreate(PETSC_COMM_WORLD,&eps);
 65:   EPSSetOperators(eps,A,NULL);
 66:   EPSSetProblemType(eps,EPS_HEP);
 67:   EPSSetType(eps,EPSPRIMME);

 69:   /*
 70:      Set several options
 71:   */
 72:   EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL);
 73:   EPSGetST(eps,&st);
 74:   STSetType(st,STPRECOND);
 75:   STGetKSP(st,&ksp);
 76:   KSPGetPC(ksp,&pc);
 77:   KSPSetType(ksp,KSPPREONLY);
 78:   PCSetType(pc,PCICC);

 80:   EPSPRIMMESetBlockSize(eps,4);
 81:   EPSPRIMMESetMethod(eps,EPS_PRIMME_GD_OLSEN_PLUSK);
 82:   EPSSetFromOptions(eps);

 84:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 85:                  Compute eigenvalues and display info
 86:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 88:   EPSSolve(eps);
 89:   EPSPRIMMEGetBlockSize(eps,&bs);
 90:   EPSPRIMMEGetMethod(eps,&meth);
 91:   PetscPrintf(PETSC_COMM_WORLD," PRIMME: using block size %D, method %s\n",bs,EPSPRIMMEMethods[meth]);

 93:   EPSErrorView(eps,EPS_ERROR_ABSOLUTE,NULL);

 95:   EPSDestroy(&eps);
 96:   MatDestroy(&A);
 97:   SlepcFinalize();
 98:   return ierr;
 99: }

101: /*TEST

103:    build:
104:       requires: primme

106:    testset:
107:       args: -eps_nev 4
108:       requires: primme
109:       output_file: output/test34_1.out
110:       test:
111:          suffix: 1
112:       test:
113:          suffix: 2
114:          args: -st_pc_type bjacobi -eps_target 0.01 -eps_target_real -eps_refined
115:          nsize: 2
116:       test:
117:          suffix: 3
118:          args: -eps_smallest_magnitude -eps_harmonic

120: TEST*/