Actual source code: ex27.c
slepc-3.23.1 2025-05-01
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[] = "Simple nonlinear eigenproblem using the NLEIGS solver.\n\n"
12: "The command line options are:\n"
13: " -n <n>, where <n> = matrix dimension.\n"
14: " -split <0/1>, to select the split form in the problem definition (enabled by default)\n";
16: /*
17: Solve T(lambda)x=0 using NLEIGS solver
18: with T(lambda) = -D+sqrt(lambda)*I
19: where D is the Laplacian operator in 1 dimension
20: and with the interpolation interval [.01,16]
21: */
23: #include <slepcnep.h>
25: /*
26: User-defined routines
27: */
28: PetscErrorCode FormFunction(NEP,PetscScalar,Mat,Mat,void*);
29: PetscErrorCode FormJacobian(NEP,PetscScalar,Mat,void*);
30: PetscErrorCode ComputeSingularities(NEP,PetscInt*,PetscScalar*,void*);
32: int main(int argc,char **argv)
33: {
34: NEP nep; /* nonlinear eigensolver context */
35: Mat F,J,A[2];
36: NEPType type;
37: PetscInt n=100,nev,Istart,Iend,i;
38: PetscBool terse,split=PETSC_TRUE;
39: RG rg;
40: FN f[2];
41: PetscScalar coeffs;
43: PetscFunctionBeginUser;
44: PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
45: PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
46: PetscCall(PetscOptionsGetBool(NULL,NULL,"-split",&split,NULL));
47: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nSquare root eigenproblem, n=%" PetscInt_FMT "%s\n\n",n,split?" (in split form)":""));
49: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
50: Create nonlinear eigensolver context
51: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
53: PetscCall(NEPCreate(PETSC_COMM_WORLD,&nep));
55: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
56: Select the NLEIGS solver and set required options for it
57: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
59: PetscCall(NEPSetType(nep,NEPNLEIGS));
60: PetscCall(NEPNLEIGSSetSingularitiesFunction(nep,ComputeSingularities,NULL));
61: PetscCall(NEPGetRG(nep,&rg));
62: PetscCall(RGSetType(rg,RGINTERVAL));
63: #if defined(PETSC_USE_COMPLEX)
64: PetscCall(RGIntervalSetEndpoints(rg,0.01,16.0,-0.001,0.001));
65: #else
66: PetscCall(RGIntervalSetEndpoints(rg,0.01,16.0,0,0));
67: #endif
68: PetscCall(NEPSetTarget(nep,1.1));
70: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
71: Define the nonlinear problem
72: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
74: if (split) {
75: /*
76: Create matrices for the split form
77: */
78: PetscCall(MatCreate(PETSC_COMM_WORLD,&A[0]));
79: PetscCall(MatSetSizes(A[0],PETSC_DECIDE,PETSC_DECIDE,n,n));
80: PetscCall(MatSetFromOptions(A[0]));
81: PetscCall(MatGetOwnershipRange(A[0],&Istart,&Iend));
82: for (i=Istart;i<Iend;i++) {
83: if (i>0) PetscCall(MatSetValue(A[0],i,i-1,1.0,INSERT_VALUES));
84: if (i<n-1) PetscCall(MatSetValue(A[0],i,i+1,1.0,INSERT_VALUES));
85: PetscCall(MatSetValue(A[0],i,i,-2.0,INSERT_VALUES));
86: }
87: PetscCall(MatAssemblyBegin(A[0],MAT_FINAL_ASSEMBLY));
88: PetscCall(MatAssemblyEnd(A[0],MAT_FINAL_ASSEMBLY));
90: PetscCall(MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,n,n,1.0,&A[1]));
92: /*
93: Define functions for the split form
94: */
95: PetscCall(FNCreate(PETSC_COMM_WORLD,&f[0]));
96: PetscCall(FNSetType(f[0],FNRATIONAL));
97: coeffs = 1.0;
98: PetscCall(FNRationalSetNumerator(f[0],1,&coeffs));
99: PetscCall(FNCreate(PETSC_COMM_WORLD,&f[1]));
100: PetscCall(FNSetType(f[1],FNSQRT));
101: PetscCall(NEPSetSplitOperator(nep,2,A,f,SUBSET_NONZERO_PATTERN));
103: } else {
104: /*
105: Callback form: create matrix and set Function evaluation routine
106: */
107: PetscCall(MatCreate(PETSC_COMM_WORLD,&F));
108: PetscCall(MatSetSizes(F,PETSC_DECIDE,PETSC_DECIDE,n,n));
109: PetscCall(MatSetFromOptions(F));
110: PetscCall(MatSeqAIJSetPreallocation(F,3,NULL));
111: PetscCall(MatMPIAIJSetPreallocation(F,3,NULL,1,NULL));
112: PetscCall(NEPSetFunction(nep,F,F,FormFunction,NULL));
114: PetscCall(MatCreate(PETSC_COMM_WORLD,&J));
115: PetscCall(MatSetSizes(J,PETSC_DECIDE,PETSC_DECIDE,n,n));
116: PetscCall(MatSetFromOptions(J));
117: PetscCall(MatSeqAIJSetPreallocation(J,1,NULL));
118: PetscCall(MatMPIAIJSetPreallocation(J,1,NULL,1,NULL));
119: PetscCall(NEPSetJacobian(nep,J,FormJacobian,NULL));
120: }
122: /*
123: Set solver parameters at runtime
124: */
125: PetscCall(NEPSetFromOptions(nep));
127: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
128: Solve the eigensystem
129: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
130: PetscCall(NEPSolve(nep));
131: PetscCall(NEPGetType(nep,&type));
132: PetscCall(PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n",type));
133: PetscCall(NEPGetDimensions(nep,&nev,NULL,NULL));
134: PetscCall(PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev));
136: /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
137: Display solution and clean up
138: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
140: /* show detailed info unless -terse option is given by user */
141: PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
142: if (terse) PetscCall(NEPErrorView(nep,NEP_ERROR_BACKWARD,NULL));
143: else {
144: PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
145: PetscCall(NEPConvergedReasonView(nep,PETSC_VIEWER_STDOUT_WORLD));
146: PetscCall(NEPErrorView(nep,NEP_ERROR_BACKWARD,PETSC_VIEWER_STDOUT_WORLD));
147: PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
148: }
149: PetscCall(NEPDestroy(&nep));
150: if (split) {
151: PetscCall(MatDestroy(&A[0]));
152: PetscCall(MatDestroy(&A[1]));
153: PetscCall(FNDestroy(&f[0]));
154: PetscCall(FNDestroy(&f[1]));
155: } else {
156: PetscCall(MatDestroy(&F));
157: PetscCall(MatDestroy(&J));
158: }
159: PetscCall(SlepcFinalize());
160: return 0;
161: }
163: /* ------------------------------------------------------------------- */
164: /*
165: FormFunction - Computes Function matrix T(lambda)
166: */
167: PetscErrorCode FormFunction(NEP nep,PetscScalar lambda,Mat fun,Mat B,void *ctx)
168: {
169: PetscInt i,n,col[3],Istart,Iend;
170: PetscBool FirstBlock=PETSC_FALSE,LastBlock=PETSC_FALSE;
171: PetscScalar value[3],t;
173: PetscFunctionBeginUser;
174: /*
175: Compute Function entries and insert into matrix
176: */
177: t = PetscSqrtScalar(lambda);
178: PetscCall(MatGetSize(fun,&n,NULL));
179: PetscCall(MatGetOwnershipRange(fun,&Istart,&Iend));
180: if (Istart==0) FirstBlock=PETSC_TRUE;
181: if (Iend==n) LastBlock=PETSC_TRUE;
182: value[0]=1.0; value[1]=t-2.0; value[2]=1.0;
183: for (i=(FirstBlock? Istart+1: Istart); i<(LastBlock? Iend-1: Iend); i++) {
184: col[0]=i-1; col[1]=i; col[2]=i+1;
185: PetscCall(MatSetValues(fun,1,&i,3,col,value,INSERT_VALUES));
186: }
187: if (LastBlock) {
188: i=n-1; col[0]=n-2; col[1]=n-1;
189: PetscCall(MatSetValues(fun,1,&i,2,col,value,INSERT_VALUES));
190: }
191: if (FirstBlock) {
192: i=0; col[0]=0; col[1]=1; value[0]=t-2.0; value[1]=1.0;
193: PetscCall(MatSetValues(fun,1,&i,2,col,value,INSERT_VALUES));
194: }
196: /*
197: Assemble matrix
198: */
199: PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
200: PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));
201: if (fun != B) {
202: PetscCall(MatAssemblyBegin(fun,MAT_FINAL_ASSEMBLY));
203: PetscCall(MatAssemblyEnd(fun,MAT_FINAL_ASSEMBLY));
204: }
205: PetscFunctionReturn(PETSC_SUCCESS);
206: }
208: /* ------------------------------------------------------------------- */
209: /*
210: FormJacobian - Computes Jacobian matrix T'(lambda)
211: */
212: PetscErrorCode FormJacobian(NEP nep,PetscScalar lambda,Mat jac,void *ctx)
213: {
214: Vec d;
216: PetscFunctionBeginUser;
217: PetscCall(MatCreateVecs(jac,&d,NULL));
218: PetscCall(VecSet(d,0.5/PetscSqrtScalar(lambda)));
219: PetscCall(MatDiagonalSet(jac,d,INSERT_VALUES));
220: PetscCall(VecDestroy(&d));
221: PetscFunctionReturn(PETSC_SUCCESS);
222: }
224: /* ------------------------------------------------------------------- */
225: /*
226: ComputeSingularities - Computes maxnp points (at most) in the complex plane where
227: the function T(.) is not analytic.
229: In this case, we discretize the singularity region (-inf,0)~(-1e+6,-1e-5)
230: */
231: PetscErrorCode ComputeSingularities(NEP nep,PetscInt *maxnp,PetscScalar *xi,void *pt)
232: {
233: PetscReal h;
234: PetscInt i;
236: PetscFunctionBeginUser;
237: h = 11.0/(*maxnp-1);
238: xi[0] = -1e-5; xi[*maxnp-1] = -1e+6;
239: for (i=1;i<*maxnp-1;i++) xi[i] = -PetscPowReal(10,-5+h*i);
240: PetscFunctionReturn(PETSC_SUCCESS);
241: }
243: /*TEST
245: testset:
246: args: -nep_nev 3 -terse
247: output_file: output/ex27_1.out
248: requires: !single
249: filter: sed -e "s/[+-]0\.0*i//g"
250: test:
251: suffix: 1
252: args: -nep_nleigs_interpolation_degree 90
253: test:
254: suffix: 3
255: args: -nep_tol 1e-8 -nep_nleigs_rk_shifts 1.06,1.1,1.12,1.15 -nep_conv_norm -nep_nleigs_interpolation_degree 20
256: test:
257: suffix: 5_cuda
258: args: -mat_type aijcusparse
259: requires: cuda
260: test:
261: suffix: 5_hip
262: args: -mat_type aijhipsparse
263: requires: hip
265: testset:
266: args: -split 0 -nep_nev 3 -terse
267: output_file: output/ex27_2.out
268: filter: sed -e "s/[+-]0\.0*i//g"
269: test:
270: suffix: 2
271: args: -nep_nleigs_interpolation_degree 90
272: requires: !single
273: test:
274: suffix: 4
275: args: -nep_nleigs_rk_shifts 1.06,1.1,1.12,1.15 -nep_nleigs_interpolation_degree 20
276: requires: double
277: test:
278: suffix: 6_cuda
279: args: -mat_type aijcusparse
280: requires: cuda !single
281: test:
282: suffix: 6_hip
283: args: -mat_type aijhipsparse
284: requires: hip !single
286: testset:
287: args: -split 0 -nep_type ciss -nep_ciss_extraction {{ritz hankel caa}} -rg_type ellipse -rg_ellipse_center 8 -rg_ellipse_radius .7 -nep_ciss_moments 4 -rg_ellipse_vscale 0.1 -terse
288: requires: complex !single
289: output_file: output/ex27_7.out
290: timeoutfactor: 2
291: test:
292: suffix: 7
293: test:
294: suffix: 7_par
295: nsize: 2
296: args: -nep_ciss_partitions 2
298: testset:
299: args: -nep_type ciss -rg_type ellipse -rg_ellipse_center 8 -rg_ellipse_radius .7 -rg_ellipse_vscale 0.1 -terse
300: requires: complex
301: filter: sed -e "s/ (in split form)//" | sed -e "s/56925/56924/" | sed -e "s/60753/60754/" | sed -e "s/92630/92629/" | sed -e "s/24705/24706/"
302: output_file: output/ex27_7.out
303: timeoutfactor: 2
304: test:
305: suffix: 8
306: test:
307: suffix: 8_parallel
308: nsize: 4
309: args: -nep_ciss_partitions 4 -ds_parallel distributed
310: test:
311: suffix: 8_hpddm
312: args: -nep_ciss_ksp_type hpddm
313: requires: hpddm
315: test:
316: suffix: 9
317: args: -nep_nev 4 -n 20 -terse
318: requires: !single
319: filter: sed -e "s/[+-]0\.0*i//g"
321: TEST*/