Date: 2022-11-02T11:47:37+00:00

Actual source code: test2.c
slepc-3.18.1 2022-11-02
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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 NEP interface functions.\n\n";

     13: #include <slepcnep.h>

     15: int main(int argc,char **argv)
     16: {
     17:   Mat                  A[3],B;      /* problem matrices */
     18:   FN                   f[3],g;      /* problem functions */
     19:   NEP                  nep;         /* eigenproblem solver context */
     20:   DS                   ds;
     21:   RG                   rg;
     22:   PetscReal            tol;
     23:   PetscScalar          coeffs[2],target;
     24:   PetscInt             n=20,i,its,nev,ncv,mpd,Istart,Iend,nterm;
     25:   PetscBool            twoside;
     26:   NEPWhich             which;
     27:   NEPConvergedReason   reason;
     28:   NEPType              type;
     29:   NEPRefine            refine;
     30:   NEPRefineScheme      rscheme;
     31:   NEPConv              conv;
     32:   NEPStop              stop;
     33:   NEPProblemType       ptype;
     34:   MatStructure         mstr;
     35:   PetscViewerAndFormat *vf;

     38:   SlepcInitialize(&argc,&argv,(char*)0,help);
     39:   PetscPrintf(PETSC_COMM_WORLD,"\nDiagonal Nonlinear Eigenproblem, n=%" PetscInt_FMT "\n\n",n);

     41:   /*
     42:      Matrices
     43:   */
     44:   MatCreate(PETSC_COMM_WORLD,&A[0]);
     45:   MatSetSizes(A[0],PETSC_DECIDE,PETSC_DECIDE,n,n);
     46:   MatSetFromOptions(A[0]);
     47:   MatSetUp(A[0]);
     48:   MatGetOwnershipRange(A[0],&Istart,&Iend);
     49:   for (i=Istart;i<Iend;i++) MatSetValue(A[0],i,i,i+1,INSERT_VALUES);
     50:   MatAssemblyBegin(A[0],MAT_FINAL_ASSEMBLY);
     51:   MatAssemblyEnd(A[0],MAT_FINAL_ASSEMBLY);

     53:   MatCreate(PETSC_COMM_WORLD,&A[1]);
     54:   MatSetSizes(A[1],PETSC_DECIDE,PETSC_DECIDE,n,n);
     55:   MatSetFromOptions(A[1]);
     56:   MatSetUp(A[1]);
     57:   MatGetOwnershipRange(A[1],&Istart,&Iend);
     58:   for (i=Istart;i<Iend;i++) MatSetValue(A[1],i,i,1.0,INSERT_VALUES);
     59:   MatAssemblyBegin(A[1],MAT_FINAL_ASSEMBLY);
     60:   MatAssemblyEnd(A[1],MAT_FINAL_ASSEMBLY);

     62:   MatCreate(PETSC_COMM_WORLD,&A[2]);
     63:   MatSetSizes(A[2],PETSC_DECIDE,PETSC_DECIDE,n,n);
     64:   MatSetFromOptions(A[2]);
     65:   MatSetUp(A[2]);
     66:   MatGetOwnershipRange(A[1],&Istart,&Iend);
     67:   for (i=Istart;i<Iend;i++) MatSetValue(A[2],i,i,n/(PetscReal)(i+1),INSERT_VALUES);
     68:   MatAssemblyBegin(A[2],MAT_FINAL_ASSEMBLY);
     69:   MatAssemblyEnd(A[2],MAT_FINAL_ASSEMBLY);

     71:   /*
     72:      Functions: f0=-lambda, f1=1.0, f2=sqrt(lambda)
     73:   */
     74:   FNCreate(PETSC_COMM_WORLD,&f[0]);
     75:   FNSetType(f[0],FNRATIONAL);
     76:   coeffs[0] = -1.0; coeffs[1] = 0.0;
     77:   FNRationalSetNumerator(f[0],2,coeffs);

     79:   FNCreate(PETSC_COMM_WORLD,&f[1]);
     80:   FNSetType(f[1],FNRATIONAL);
     81:   coeffs[0] = 1.0;
     82:   FNRationalSetNumerator(f[1],1,coeffs);

     84:   FNCreate(PETSC_COMM_WORLD,&f[2]);
     85:   FNSetType(f[2],FNSQRT);

     87:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     88:              Create eigensolver and test interface functions
     89:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
     90:   NEPCreate(PETSC_COMM_WORLD,&nep);
     91:   NEPSetSplitOperator(nep,3,A,f,SAME_NONZERO_PATTERN);
     92:   NEPGetSplitOperatorInfo(nep,&nterm,&mstr);
     93:   PetscPrintf(PETSC_COMM_WORLD," Nonlinear function with %" PetscInt_FMT " terms, with %s nonzero pattern\n",nterm,MatStructures[mstr]);
     94:   NEPGetSplitOperatorTerm(nep,0,&B,&g);
     95:   MatView(B,NULL);
     96:   FNView(g,NULL);

     98:   NEPSetType(nep,NEPRII);
     99:   NEPGetType(nep,&type);
    100:   PetscPrintf(PETSC_COMM_WORLD," Type set to %s\n",type);
    101:   NEPGetTwoSided(nep,&twoside);
    102:   PetscPrintf(PETSC_COMM_WORLD," Two-sided flag = %s\n",twoside?"true":"false");

    104:   NEPGetProblemType(nep,&ptype);
    105:   PetscPrintf(PETSC_COMM_WORLD," Problem type before changing = %d",(int)ptype);
    106:   NEPSetProblemType(nep,NEP_RATIONAL);
    107:   NEPGetProblemType(nep,&ptype);
    108:   PetscPrintf(PETSC_COMM_WORLD," ... changed to %d.\n",(int)ptype);

    110:   NEPSetRefine(nep,NEP_REFINE_SIMPLE,1,1e-9,2,NEP_REFINE_SCHEME_EXPLICIT);
    111:   NEPGetRefine(nep,&refine,NULL,&tol,&its,&rscheme);
    112:   PetscPrintf(PETSC_COMM_WORLD," Refinement: %s, tol=%g, its=%" PetscInt_FMT ", scheme=%s\n",NEPRefineTypes[refine],(double)tol,its,NEPRefineSchemes[rscheme]);

    114:   NEPSetTarget(nep,1.1);
    115:   NEPGetTarget(nep,&target);
    116:   NEPSetWhichEigenpairs(nep,NEP_TARGET_MAGNITUDE);
    117:   NEPGetWhichEigenpairs(nep,&which);
    118:   PetscPrintf(PETSC_COMM_WORLD," Which = %d, target = %g\n",(int)which,(double)PetscRealPart(target));

    120:   NEPSetDimensions(nep,1,12,PETSC_DEFAULT);
    121:   NEPGetDimensions(nep,&nev,&ncv,&mpd);
    122:   PetscPrintf(PETSC_COMM_WORLD," Dimensions: nev=%" PetscInt_FMT ", ncv=%" PetscInt_FMT ", mpd=%" PetscInt_FMT "\n",nev,ncv,mpd);

    124:   NEPSetTolerances(nep,1.0e-6,200);
    125:   NEPGetTolerances(nep,&tol,&its);
    126:   PetscPrintf(PETSC_COMM_WORLD," Tolerance = %.6f, max_its = %" PetscInt_FMT "\n",(double)tol,its);

    128:   NEPSetConvergenceTest(nep,NEP_CONV_ABS);
    129:   NEPGetConvergenceTest(nep,&conv);
    130:   NEPSetStoppingTest(nep,NEP_STOP_BASIC);
    131:   NEPGetStoppingTest(nep,&stop);
    132:   PetscPrintf(PETSC_COMM_WORLD," Convergence test = %d, stopping test = %d\n",(int)conv,(int)stop);

    134:   PetscViewerAndFormatCreate(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_DEFAULT,&vf);
    135:   NEPMonitorSet(nep,(PetscErrorCode (*)(NEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*))NEPMonitorFirst,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
    136:   NEPMonitorCancel(nep);

    138:   NEPGetDS(nep,&ds);
    139:   DSView(ds,NULL);
    140:   NEPSetFromOptions(nep);

    142:   NEPGetRG(nep,&rg);
    143:   RGView(rg,NULL);

    145:   NEPSolve(nep);
    146:   NEPGetConvergedReason(nep,&reason);
    147:   PetscPrintf(PETSC_COMM_WORLD," Finished - converged reason = %d\n",(int)reason);

    149:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    150:                     Display solution and clean up
    151:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    152:   NEPErrorView(nep,NEP_ERROR_RELATIVE,NULL);
    153:   NEPDestroy(&nep);
    154:   MatDestroy(&A[0]);
    155:   MatDestroy(&A[1]);
    156:   MatDestroy(&A[2]);
    157:   FNDestroy(&f[0]);
    158:   FNDestroy(&f[1]);
    159:   FNDestroy(&f[2]);
    160:   SlepcFinalize();
    161:   return 0;
    162: }

    164: /*TEST

    166:    test:
    167:       suffix: 1

    169: TEST*/