Actual source code: test11.c
slepc-3.17.0 2022-03-31
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 the CISS solver with the problem of ex22.\n\n"
12: "The command line options are:\n"
13: " -n <n>, where <n> = number of grid subdivisions.\n"
14: " -tau <tau>, where <tau> is the delay parameter.\n\n";
16: /*
17: Solve parabolic partial differential equation with time delay tau
19: u_t = u_xx + a*u(t) + b*u(t-tau)
20: u(0,t) = u(pi,t) = 0
22: with a = 20 and b(x) = -4.1+x*(1-exp(x-pi)).
24: Discretization leads to a DDE of dimension n
26: -u' = A*u(t) + B*u(t-tau)
28: which results in the nonlinear eigenproblem
30: (-lambda*I + A + exp(-tau*lambda)*B)*u = 0
31: */
33: #include <slepcnep.h>
35: int main(int argc,char **argv)
36: {
37: NEP nep;
38: Mat Id,A,B,mats[3];
39: FN f1,f2,f3,funs[3];
40: RG rg;
41: KSP *ksp;
42: PC pc;
43: NEPCISSExtraction ext;
44: PetscScalar coeffs[2],b;
45: PetscInt n=128,Istart,Iend,i,nsolve;
46: PetscReal tau=0.001,h,a=20,xi;
47: PetscBool flg,terse;
49: SlepcInitialize(&argc,&argv,(char*)0,help);
50: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
51: PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL);
52: PetscPrintf(PETSC_COMM_WORLD,"\n1-D Delay Eigenproblem, n=%" PetscInt_FMT ", tau=%g\n\n",n,(double)tau);
53: h = PETSC_PI/(PetscReal)(n+1);
55: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
56: Create nonlinear eigensolver context
57: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
59: NEPCreate(PETSC_COMM_WORLD,&nep);
61: /* Identity matrix */
62: MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,n,n,1.0,&Id);
63: MatSetOption(Id,MAT_HERMITIAN,PETSC_TRUE);
65: /* A = 1/h^2*tridiag(1,-2,1) + a*I */
66: MatCreate(PETSC_COMM_WORLD,&A);
67: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
68: MatSetFromOptions(A);
69: MatSetUp(A);
70: MatGetOwnershipRange(A,&Istart,&Iend);
71: for (i=Istart;i<Iend;i++) {
72: if (i>0) MatSetValue(A,i,i-1,1.0/(h*h),INSERT_VALUES);
73: if (i<n-1) MatSetValue(A,i,i+1,1.0/(h*h),INSERT_VALUES);
74: MatSetValue(A,i,i,-2.0/(h*h)+a,INSERT_VALUES);
75: }
76: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
77: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
78: MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);
80: /* B = diag(b(xi)) */
81: MatCreate(PETSC_COMM_WORLD,&B);
82: MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,n,n);
83: MatSetFromOptions(B);
84: MatSetUp(B);
85: MatGetOwnershipRange(B,&Istart,&Iend);
86: for (i=Istart;i<Iend;i++) {
87: xi = (i+1)*h;
88: b = -4.1+xi*(1.0-PetscExpReal(xi-PETSC_PI));
89: MatSetValues(B,1,&i,1,&i,&b,INSERT_VALUES);
90: }
91: MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
92: MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
93: MatSetOption(B,MAT_HERMITIAN,PETSC_TRUE);
95: /* Functions: f1=-lambda, f2=1.0, f3=exp(-tau*lambda) */
96: FNCreate(PETSC_COMM_WORLD,&f1);
97: FNSetType(f1,FNRATIONAL);
98: coeffs[0] = -1.0; coeffs[1] = 0.0;
99: FNRationalSetNumerator(f1,2,coeffs);
101: FNCreate(PETSC_COMM_WORLD,&f2);
102: FNSetType(f2,FNRATIONAL);
103: coeffs[0] = 1.0;
104: FNRationalSetNumerator(f2,1,coeffs);
106: FNCreate(PETSC_COMM_WORLD,&f3);
107: FNSetType(f3,FNEXP);
108: FNSetScale(f3,-tau,1.0);
110: /* Set the split operator */
111: mats[0] = A; funs[0] = f2;
112: mats[1] = Id; funs[1] = f1;
113: mats[2] = B; funs[2] = f3;
114: NEPSetSplitOperator(nep,3,mats,funs,SUBSET_NONZERO_PATTERN);
116: /* Customize nonlinear solver; set runtime options */
117: NEPSetType(nep,NEPCISS);
118: NEPSetDimensions(nep,1,24,PETSC_DEFAULT);
119: NEPSetTolerances(nep,1e-9,PETSC_DEFAULT);
120: NEPGetRG(nep,&rg);
121: RGSetType(rg,RGELLIPSE);
122: RGEllipseSetParameters(rg,10.0,9.5,0.1);
123: NEPCISSSetSizes(nep,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,1,PETSC_DEFAULT,PETSC_TRUE);
124: NEPCISSGetKSPs(nep,&nsolve,&ksp);
125: for (i=0;i<nsolve;i++) {
126: KSPSetTolerances(ksp[i],1e-12,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
127: KSPSetType(ksp[i],KSPBCGS);
128: KSPGetPC(ksp[i],&pc);
129: PCSetType(pc,PCSOR);
130: }
131: NEPSetFromOptions(nep);
133: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
134: Solve the eigensystem
135: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
137: PetscObjectTypeCompare((PetscObject)nep,NEPCISS,&flg);
138: if (flg) {
139: NEPCISSGetExtraction(nep,&ext);
140: PetscPrintf(PETSC_COMM_WORLD," Running CISS with %" PetscInt_FMT " KSP solvers (%s extraction)\n",nsolve,NEPCISSExtractions[ext]);
141: }
142: NEPSolve(nep);
144: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
145: Display solution and clean up
146: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
148: /* show detailed info unless -terse option is given by user */
149: PetscOptionsHasName(NULL,NULL,"-terse",&terse);
150: if (terse) NEPErrorView(nep,NEP_ERROR_RELATIVE,NULL);
151: else {
152: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
153: NEPConvergedReasonView(nep,PETSC_VIEWER_STDOUT_WORLD);
154: NEPErrorView(nep,NEP_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
155: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
156: }
157: NEPDestroy(&nep);
158: MatDestroy(&Id);
159: MatDestroy(&A);
160: MatDestroy(&B);
161: FNDestroy(&f1);
162: FNDestroy(&f2);
163: FNDestroy(&f3);
164: SlepcFinalize();
165: return 0;
166: }
168: /*TEST
170: build:
171: requires: complex
173: testset:
174: args: -nep_ciss_extraction {{ritz hankel caa}} -terse
175: requires: complex !single
176: output_file: output/test11_1.out
177: filter: sed -e "s/([A-Z]* extraction)//"
178: test:
179: suffix: 1
180: args: -nep_ciss_delta 1e-10
181: test:
182: suffix: 2
183: nsize: 2
184: args: -nep_ciss_partitions 2
185: test:
186: suffix: 3
187: args: -nep_ciss_moments 4 -nep_ciss_blocksize 5 -nep_ciss_refine_inner 1 -nep_ciss_refine_blocksize 2
189: test:
190: suffix: 4
191: args: -terse -nep_view
192: requires: complex !single
193: filter: grep -v tolerance
195: TEST*/