Actual source code: test14.c
slepc-3.17.2 2022-08-09
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[] = "Tests a user-defined convergence test in NEP.\n\n"
12: "The command line options are:\n"
13: " -n <n>, where <n> = matrix dimension.\n";
15: /*
16: Solve T(lambda)x=0 with T(lambda) = -D+sqrt(lambda)*I
17: where D is the Laplacian operator in 1 dimension
18: */
20: #include <slepcnep.h>
22: /*
23: MyConvergedRel - Convergence test relative to the norm of D (given in ctx).
24: */
25: PetscErrorCode MyConvergedRel(NEP nep,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)
26: {
27: PetscReal norm = *(PetscReal*)ctx;
29: *errest = res/norm;
30: PetscFunctionReturn(0);
31: }
33: int main(int argc,char **argv)
34: {
35: NEP nep; /* nonlinear eigensolver context */
36: Mat A[2];
37: PetscInt n=100,Istart,Iend,i;
38: PetscBool terse;
39: PetscReal norm;
40: FN f[2];
41: PetscScalar coeffs;
43: SlepcInitialize(&argc,&argv,(char*)0,help);
44: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
45: PetscPrintf(PETSC_COMM_WORLD,"\nSquare root eigenproblem, n=%" PetscInt_FMT "\n\n",n);
47: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
48: Create nonlinear eigensolver, define problem in split form
49: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
51: NEPCreate(PETSC_COMM_WORLD,&nep);
53: /* Create matrices */
54: MatCreate(PETSC_COMM_WORLD,&A[0]);
55: MatSetSizes(A[0],PETSC_DECIDE,PETSC_DECIDE,n,n);
56: MatSetFromOptions(A[0]);
57: MatSetUp(A[0]);
58: MatGetOwnershipRange(A[0],&Istart,&Iend);
59: for (i=Istart;i<Iend;i++) {
60: if (i>0) MatSetValue(A[0],i,i-1,1.0,INSERT_VALUES);
61: if (i<n-1) MatSetValue(A[0],i,i+1,1.0,INSERT_VALUES);
62: MatSetValue(A[0],i,i,-2.0,INSERT_VALUES);
63: }
64: MatAssemblyBegin(A[0],MAT_FINAL_ASSEMBLY);
65: MatAssemblyEnd(A[0],MAT_FINAL_ASSEMBLY);
67: MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,n,n,1.0,&A[1]);
69: /* Define functions */
70: FNCreate(PETSC_COMM_WORLD,&f[0]);
71: FNSetType(f[0],FNRATIONAL);
72: coeffs = 1.0;
73: FNRationalSetNumerator(f[0],1,&coeffs);
74: FNCreate(PETSC_COMM_WORLD,&f[1]);
75: FNSetType(f[1],FNSQRT);
76: NEPSetSplitOperator(nep,2,A,f,SUBSET_NONZERO_PATTERN);
78: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
79: Set some options and solve
80: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
82: NEPSetTarget(nep,1.1);
84: /* setup convergence test relative to the norm of D */
85: MatNorm(A[0],NORM_1,&norm);
86: NEPSetConvergenceTestFunction(nep,MyConvergedRel,&norm,NULL);
88: NEPSetFromOptions(nep);
89: NEPSolve(nep);
91: /* show detailed info unless -terse option is given by user */
92: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
93: if (terse) NEPErrorView(nep,NEP_ERROR_BACKWARD,NULL);
94: else {
95: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
96: NEPConvergedReasonView(nep,PETSC_VIEWER_STDOUT_WORLD);
97: NEPErrorView(nep,NEP_ERROR_BACKWARD,PETSC_VIEWER_STDOUT_WORLD);
98: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
99: }
100: NEPDestroy(&nep);
101: MatDestroy(&A[0]);
102: MatDestroy(&A[1]);
103: FNDestroy(&f[0]);
104: FNDestroy(&f[1]);
105: SlepcFinalize();
106: return 0;
107: }
109: /*TEST
111: test:
112: suffix: 1
113: args: -nep_type slp -nep_nev 2 -terse
115: TEST*/