Actual source code: gun.c
slepc-3.18.2 2023-01-26
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: */
10: /*
11: This example implements one of the problems found at
12: NLEVP: A Collection of Nonlinear Eigenvalue Problems,
13: The University of Manchester.
14: The details of the collection can be found at:
15: [1] T. Betcke et al., "NLEVP: A Collection of Nonlinear Eigenvalue
16: Problems", ACM Trans. Math. Software 39(2), Article 7, 2013.
18: The gun problem arises from model of a radio-frequency gun cavity, with
19: the complex nonlinear function
20: T(lambda) = K-lambda*M+i*lambda^(1/2)*W1+i*(lambda-108.8774^2)^(1/2)*W2
22: Data files can be downloaded from https://slepc.upv.es/datafiles
23: */
25: static char help[] = "Radio-frequency gun cavity.\n\n"
26: "The command line options are:\n"
27: "-K <filename1> -M <filename2> -W1 <filename3> -W2 <filename4>, where filename1,..,filename4 are files containing the matrices in PETSc binary form defining the GUN problem.\n\n";
29: #include <slepcnep.h>
31: #define NMAT 4
32: #define SIGMA 108.8774
34: int main(int argc,char **argv)
35: {
36: Mat A[NMAT]; /* problem matrices */
37: FN f[NMAT]; /* functions to define the nonlinear operator */
38: FN ff[2]; /* auxiliary functions to define the nonlinear operator */
39: NEP nep; /* nonlinear eigensolver context */
40: PetscBool terse,flg;
41: const char* string[NMAT]={"-K","-M","-W1","-W2"};
42: char filename[PETSC_MAX_PATH_LEN];
43: PetscScalar numer[2],sigma;
44: PetscInt i;
45: PetscViewer viewer;
48: SlepcInitialize(&argc,&argv,(char*)0,help);
50: PetscPrintf(PETSC_COMM_WORLD,"GUN problem\n\n");
51: #if !defined(PETSC_USE_COMPLEX)
52: SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This example requires complex scalars!");
53: #endif
55: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
56: Load the problem matrices
57: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
59: for (i=0;i<NMAT;i++) {
60: PetscOptionsGetString(NULL,NULL,string[i],filename,sizeof(filename),&flg);
62: PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
63: MatCreate(PETSC_COMM_WORLD,&A[i]);
64: MatSetFromOptions(A[i]);
65: MatLoad(A[i],viewer);
66: PetscViewerDestroy(&viewer);
67: }
69: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
70: Create the problem functions
71: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
73: /* f1=1 */
74: FNCreate(PETSC_COMM_WORLD,&f[0]);
75: FNSetType(f[0],FNRATIONAL);
76: numer[0] = 1.0;
77: FNRationalSetNumerator(f[0],1,numer);
79: /* f2=-lambda */
80: FNCreate(PETSC_COMM_WORLD,&f[1]);
81: FNSetType(f[1],FNRATIONAL);
82: numer[0] = -1.0; numer[1] = 0.0;
83: FNRationalSetNumerator(f[1],2,numer);
85: /* f3=i*sqrt(lambda) */
86: FNCreate(PETSC_COMM_WORLD,&f[2]);
87: FNSetType(f[2],FNSQRT);
88: FNSetScale(f[2],1.0,PETSC_i);
90: /* f4=i*sqrt(lambda-sigma^2) */
91: sigma = SIGMA*SIGMA;
92: FNCreate(PETSC_COMM_WORLD,&ff[0]);
93: FNSetType(ff[0],FNSQRT);
94: FNCreate(PETSC_COMM_WORLD,&ff[1]);
95: FNSetType(ff[1],FNRATIONAL);
96: numer[0] = 1.0; numer[1] = -sigma;
97: FNRationalSetNumerator(ff[1],2,numer);
98: FNCreate(PETSC_COMM_WORLD,&f[3]);
99: FNSetType(f[3],FNCOMBINE);
100: FNCombineSetChildren(f[3],FN_COMBINE_COMPOSE,ff[1],ff[0]);
101: FNSetScale(f[3],1.0,PETSC_i);
103: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
104: Create the eigensolver and solve the problem
105: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
107: NEPCreate(PETSC_COMM_WORLD,&nep);
108: NEPSetSplitOperator(nep,4,A,f,UNKNOWN_NONZERO_PATTERN);
109: NEPSetFromOptions(nep);
111: NEPSolve(nep);
113: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
114: Display solution and clean up
115: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
117: /* show detailed info unless -terse option is given by user */
118: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
119: if (terse) NEPErrorView(nep,NEP_ERROR_RELATIVE,NULL);
120: else {
121: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
122: NEPConvergedReasonView(nep,PETSC_VIEWER_STDOUT_WORLD);
123: NEPErrorView(nep,NEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
124: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
125: }
126: NEPDestroy(&nep);
127: for (i=0;i<NMAT;i++) {
128: MatDestroy(&A[i]);
129: FNDestroy(&f[i]);
130: }
131: for (i=0;i<2;i++) FNDestroy(&ff[i]);
132: SlepcFinalize();
133: return 0;
134: }
136: /*TEST
138: build:
139: requires: complex
141: test:
142: suffix: 1
143: args: -K ${DATAFILESPATH}/matrices/complex/gun_K.petsc -M ${DATAFILESPATH}/matrices/complex/gun_M.petsc -W1 ${DATAFILESPATH}/matrices/complex/gun_W1.petsc -W2 ${DATAFILESPATH}/matrices/complex/gun_W2.petsc -nep_type nleigs -rg_type polygon -rg_polygon_vertices 12500-1i,120500-1i,120500+30000i,70000+30000i -nep_target 65000 -nep_nev 24 -terse
144: requires: double complex datafilespath !defined(PETSC_USE_64BIT_INDICES) !defined(PETSCTEST_VALGRIND)
145: timeoutfactor: 10
147: TEST*/