Actual source code: test3.c
slepc-3.18.1 2022-11-02
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 MFN interface functions.\n\n"
12: "The command line options are:\n"
13: " -n <n>, where <n> = number of grid subdivisions in x dimension.\n\n";
15: #include <slepcmfn.h>
17: int main(int argc,char **argv)
18: {
19: Mat A,B;
20: MFN mfn;
21: FN f;
22: MFNConvergedReason reason;
23: MFNType type;
24: PetscReal norm,tol;
25: Vec v,y;
26: PetscInt N,n=4,Istart,Iend,i,j,II,ncv,its,maxit;
27: PetscBool flg,testprefix=PETSC_FALSE;
28: const char *prefix;
29: PetscViewerAndFormat *vf;
32: SlepcInitialize(&argc,&argv,(char*)0,help);
33: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
34: N = n*n;
35: PetscPrintf(PETSC_COMM_WORLD,"\nSquare root of Laplacian y=sqrt(A)*e_1, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,n);
36: PetscOptionsGetBool(NULL,NULL,"-test_prefix",&testprefix,NULL);
38: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
39: Compute the discrete 2-D Laplacian, A
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<n-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);
59: MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);
61: MatCreateVecs(A,NULL,&v);
62: VecSetValue(v,0,1.0,INSERT_VALUES);
63: VecAssemblyBegin(v);
64: VecAssemblyEnd(v);
65: VecDuplicate(v,&y);
67: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
68: Create the solver, set the matrix and the function
69: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
70: MFNCreate(PETSC_COMM_WORLD,&mfn);
71: MFNSetOperator(mfn,A);
72: MFNGetFN(mfn,&f);
73: FNSetType(f,FNSQRT);
75: MFNSetType(mfn,MFNKRYLOV);
76: MFNGetType(mfn,&type);
77: PetscPrintf(PETSC_COMM_WORLD," Type set to %s\n",type);
79: /* test prefix usage */
80: if (testprefix) {
81: MFNSetOptionsPrefix(mfn,"check_");
82: MFNAppendOptionsPrefix(mfn,"myprefix_");
83: MFNGetOptionsPrefix(mfn,&prefix);
84: PetscPrintf(PETSC_COMM_WORLD," MFN prefix is currently: %s\n",prefix);
85: }
87: /* test some interface functions */
88: MFNGetOperator(mfn,&B);
89: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
90: MFNSetTolerances(mfn,1e-4,500);
91: MFNSetDimensions(mfn,6);
92: MFNSetErrorIfNotConverged(mfn,PETSC_TRUE);
93: /* test monitors */
94: PetscViewerAndFormatCreate(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_DEFAULT,&vf);
95: MFNMonitorSet(mfn,(PetscErrorCode (*)(MFN,PetscInt,PetscReal,void*))MFNMonitorDefault,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
96: /* MFNMonitorCancel(mfn); */
97: MFNSetFromOptions(mfn);
99: /* query properties and print them */
100: MFNGetTolerances(mfn,&tol,&maxit);
101: PetscPrintf(PETSC_COMM_WORLD," Tolerance: %g, max iterations: %" PetscInt_FMT "\n",(double)tol,maxit);
102: MFNGetDimensions(mfn,&ncv);
103: PetscPrintf(PETSC_COMM_WORLD," Subspace dimension: %" PetscInt_FMT "\n",ncv);
104: MFNGetErrorIfNotConverged(mfn,&flg);
105: if (flg) PetscPrintf(PETSC_COMM_WORLD," Erroring out if convergence fails\n");
107: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
108: Solve y=sqrt(A)*v
109: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
111: MFNSolve(mfn,v,y);
112: MFNGetConvergedReason(mfn,&reason);
113: MFNGetIterationNumber(mfn,&its);
114: PetscPrintf(PETSC_COMM_WORLD," Finished - converged reason = %d\n",(int)reason);
115: /* PetscPrintf(PETSC_COMM_WORLD," its = %" PetscInt_FMT "\n",its); */
116: VecNorm(y,NORM_2,&norm);
117: PetscPrintf(PETSC_COMM_WORLD," sqrt(A)*v has norm %g\n",(double)norm);
119: /*
120: Free work space
121: */
122: MFNDestroy(&mfn);
123: MatDestroy(&A);
124: VecDestroy(&v);
125: VecDestroy(&y);
126: SlepcFinalize();
127: return 0;
128: }
130: /*TEST
132: test:
133: suffix: 1
134: args: -mfn_monitor_cancel -mfn_converged_reason -mfn_view -log_exclude mfn,bv,fn -mfn_monitor draw::draw_lg -draw_virtual
135: requires: x
137: test:
138: suffix: 2
139: args: -test_prefix -check_myprefix_mfn_monitor
140: filter: sed -e "s/estimate [0-9]\.[0-9]*e[+-]\([0-9]*\)/estimate (removed)/g" | sed -e "s/4.0[0-9]*e-10/4.03e-10/"
142: TEST*/