Actual source code: test42.c

slepc-3.18.0 2022-10-01
Report Typos and Errors
  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[] = "Block-diagonal orthogonal eigenproblem.\n"
 12:   "The command line options are:\n"
 13:   "  -n <n>, where <n> = matrix dimension.\n"
 14:   "  -seed <s>, where <s> = seed for random number generation.\n\n";

 16: #include <slepceps.h>

 18: int main(int argc,char **argv)
 19: {
 20:   EPS            eps;
 21:   Mat            A;
 22:   PetscRandom    rand;
 23:   PetscScalar    val,c,s;
 24:   PetscInt       n=30,i,seed=0x12345678;
 25:   PetscMPIInt    rank;

 28:   SlepcInitialize(&argc,&argv,(char*)0,help);
 29:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 30:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 31:   PetscPrintf(PETSC_COMM_WORLD,"\nOrthogonal eigenproblem, n=%" PetscInt_FMT "\n\n",n);

 33:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 34:         Generate the matrix
 35:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 37:   PetscRandomCreate(PETSC_COMM_WORLD,&rand);
 38:   PetscRandomSetFromOptions(rand);
 39:   PetscOptionsGetInt(NULL,NULL,"-seed",&seed,NULL);
 40:   PetscRandomSetSeed(rand,seed);
 41:   PetscRandomSeed(rand);
 42:   PetscRandomSetInterval(rand,0,2*PETSC_PI);

 44:   MatCreate(PETSC_COMM_WORLD,&A);
 45:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
 46:   MatSetFromOptions(A);
 47:   MatSetUp(A);

 49:   if (!rank) {
 50:     for (i=0;i<n/2;i++) {
 51:       PetscRandomGetValue(rand,&val);
 52:       c = PetscCosReal(PetscRealPart(val));
 53:       s = PetscSinReal(PetscRealPart(val));
 54:       MatSetValue(A,2*i,2*i,c,INSERT_VALUES);
 55:       MatSetValue(A,2*i+1,2*i+1,c,INSERT_VALUES);
 56:       MatSetValue(A,2*i,2*i+1,s,INSERT_VALUES);
 57:       MatSetValue(A,2*i+1,2*i,-s,INSERT_VALUES);
 58:     }
 59:     if (n%2) MatSetValue(A,n-1,n-1,-1.0,INSERT_VALUES);
 60:   }
 61:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 62:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 64:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 65:                 Create the eigensolver and solve the problem
 66:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 68:   EPSCreate(PETSC_COMM_WORLD,&eps);
 69:   EPSSetOperators(eps,A,NULL);
 70:   EPSSetProblemType(eps,EPS_NHEP);
 71:   EPSSetWhichEigenpairs(eps,EPS_LARGEST_REAL);
 72:   EPSSetFromOptions(eps);
 73:   EPSSolve(eps);

 75:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 76:                     Display solution and clean up
 77:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 79:   EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
 80:   EPSDestroy(&eps);
 81:   MatDestroy(&A);
 82:   PetscRandomDestroy(&rand);
 83:   SlepcFinalize();
 84:   return 0;
 85: }

 87: /*TEST

 89:    testset:
 90:       requires: complex double
 91:       args: -eps_type ciss -eps_all -rg_type ring -rg_ring_center 0 -rg_ring_radius 1 -rg_ring_width 0.05 -rg_ring_startangle .93 -rg_ring_endangle .07
 92:       filter: sed -e "s/[+-]\([0-9]\.[0-9]*i\)/+-\\1/g"
 93:       test:
 94:          suffix: 1_ring
 95:          args: -eps_ciss_extraction {{ritz hankel}}

 97: TEST*/