Actual source code: ex4.c
slepc-3.17.1 2022-04-11
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[] = "Solves a standard eigensystem Ax=kx with the matrix loaded from a file.\n"
12: "This example works for both real and complex numbers.\n\n"
13: "The command line options are:\n"
14: " -file <filename>, where <filename> = matrix file in PETSc binary form.\n\n";
16: #include <slepceps.h>
18: int main(int argc,char **argv)
19: {
20: Mat A; /* operator matrix */
21: EPS eps; /* eigenproblem solver context */
22: EPSType type;
23: PetscReal tol;
24: PetscInt nev,maxit,its;
25: char filename[PETSC_MAX_PATH_LEN];
26: PetscViewer viewer;
27: PetscBool flg,terse;
29: SlepcInitialize(&argc,&argv,(char*)0,help);
31: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
32: Load the operator matrix that defines the eigensystem, Ax=kx
33: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
35: PetscPrintf(PETSC_COMM_WORLD,"\nEigenproblem stored in file.\n\n");
36: PetscOptionsGetString(NULL,NULL,"-file",filename,sizeof(filename),&flg);
39: #if defined(PETSC_USE_COMPLEX)
40: PetscPrintf(PETSC_COMM_WORLD," Reading COMPLEX matrix from a binary file...\n");
41: #else
42: PetscPrintf(PETSC_COMM_WORLD," Reading REAL matrix from a binary file...\n");
43: #endif
44: PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
45: MatCreate(PETSC_COMM_WORLD,&A);
46: MatSetFromOptions(A);
47: MatLoad(A,viewer);
48: PetscViewerDestroy(&viewer);
50: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
51: Create the eigensolver and set various options
52: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
54: /*
55: Create eigensolver context
56: */
57: EPSCreate(PETSC_COMM_WORLD,&eps);
59: /*
60: Set operators. In this case, it is a standard eigenvalue problem
61: */
62: EPSSetOperators(eps,A,NULL);
64: /*
65: Set solver parameters at runtime
66: */
67: EPSSetFromOptions(eps);
69: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
70: Solve the eigensystem
71: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
73: EPSSolve(eps);
74: EPSGetIterationNumber(eps,&its);
75: PetscPrintf(PETSC_COMM_WORLD," Number of iterations of the method: %" PetscInt_FMT "\n",its);
77: /*
78: Optional: Get some information from the solver and display it
79: */
80: EPSGetType(eps,&type);
81: PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type);
82: EPSGetDimensions(eps,&nev,NULL,NULL);
83: PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev);
84: EPSGetTolerances(eps,&tol,&maxit);
85: PetscPrintf(PETSC_COMM_WORLD," Stopping condition: tol=%.4g, maxit=%" PetscInt_FMT "\n",(double)tol,maxit);
87: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
88: Display solution and clean up
89: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
91: /* show detailed info unless -terse option is given by user */
92: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
93: if (terse) EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
94: else {
95: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
96: EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD);
97: EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
98: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
99: }
100: EPSDestroy(&eps);
101: MatDestroy(&A);
102: SlepcFinalize();
103: return 0;
104: }
106: /*TEST
108: test:
109: suffix: 1
110: args: -file ${SLEPC_DIR}/share/slepc/datafiles/matrices/rdb200.petsc -eps_nev 4 -terse
111: requires: double !complex !defined(PETSC_USE_64BIT_INDICES)
113: testset:
114: args: -file ${DATAFILESPATH}/matrices/complex/qc324.petsc -eps_type ciss -terse
115: requires: double complex datafilespath !defined(PETSC_USE_64BIT_INDICES)
116: test:
117: suffix: ciss_1
118: args: -rg_type ellipse -rg_ellipse_center -.012-.08i -rg_ellipse_radius .05
119: test:
120: suffix: ciss_2
121: args: -rg_type interval -rg_interval_endpoints -0.062,.038,-.13,-.03 -eps_max_it 1
123: TEST*/