Actual source code: test23.c
slepc-3.21.1 2024-04-26
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: */
11: static char help[] = "Test interface functions of DSNEP.\n\n";
13: #include <slepcds.h>
15: int main(int argc,char **argv)
16: {
17: DS ds;
18: FN f1,f2,f3,funs[3];
19: SlepcSC sc;
20: PetscScalar *Id,*A,*B,*wr,*wi,*X,*W,coeffs[2],auxr,alpha;
21: PetscReal tau=0.001,h,a=20,xi,re,im,nrm,aux;
22: PetscInt i,j,ii,jj,k,n=10,ld,nev,nfun,midx,ip,rits,meth,spls;
23: PetscViewer viewer;
24: PetscBool verbose;
25: RG rg;
26: DSMatType mat[3]={DS_MAT_E0,DS_MAT_E1,DS_MAT_E2};
27: #if defined(PETSC_USE_COMPLEX)
28: PetscBool flg;
29: #else
30: PetscScalar auxi;
31: #endif
33: PetscFunctionBeginUser;
34: PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
35: PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
36: PetscCall(PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL));
37: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NEP - dimension %" PetscInt_FMT ", tau=%g.\n",n,(double)tau));
38: PetscCall(PetscOptionsHasName(NULL,NULL,"-verbose",&verbose));
40: /* Create DS object and set options */
41: PetscCall(DSCreate(PETSC_COMM_WORLD,&ds));
42: PetscCall(DSSetType(ds,DSNEP));
43: #if defined(PETSC_USE_COMPLEX)
44: PetscCall(DSSetMethod(ds,1)); /* contour integral */
45: #endif
46: PetscCall(DSNEPGetRG(ds,&rg));
47: PetscCall(RGSetType(rg,RGELLIPSE));
48: PetscCall(DSNEPSetMinimality(ds,1));
49: PetscCall(DSNEPSetIntegrationPoints(ds,16));
50: PetscCall(DSNEPSetRefine(ds,PETSC_DEFAULT,2));
51: PetscCall(DSNEPSetSamplingSize(ds,25));
52: PetscCall(DSSetFromOptions(ds));
54: /* Print current options */
55: PetscCall(DSGetMethod(ds,&meth));
56: #if defined(PETSC_USE_COMPLEX)
57: PetscCheck(meth==1,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"This example requires ds_method=1");
58: PetscCall(RGIsTrivial(rg,&flg));
59: PetscCheck(!flg,PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Must at least set the radius of the ellipse");
60: #endif
62: PetscCall(DSNEPGetMinimality(ds,&midx));
63: PetscCall(DSNEPGetIntegrationPoints(ds,&ip));
64: PetscCall(DSNEPGetRefine(ds,NULL,&rits));
65: PetscCall(DSNEPGetSamplingSize(ds,&spls));
66: if (meth==1) {
67: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Contour integral method with %" PetscInt_FMT " integration points, minimality index %" PetscInt_FMT ", and sampling size %" PetscInt_FMT "\n",ip,midx,spls));
68: if (rits) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Doing %" PetscInt_FMT " iterations of Newton refinement\n",rits));
69: }
71: /* Set functions (prior to DSAllocate) */
72: PetscCall(FNCreate(PETSC_COMM_WORLD,&f1));
73: PetscCall(FNSetType(f1,FNRATIONAL));
74: coeffs[0] = -1.0; coeffs[1] = 0.0;
75: PetscCall(FNRationalSetNumerator(f1,2,coeffs));
77: PetscCall(FNCreate(PETSC_COMM_WORLD,&f2));
78: PetscCall(FNSetType(f2,FNRATIONAL));
79: coeffs[0] = 1.0;
80: PetscCall(FNRationalSetNumerator(f2,1,coeffs));
82: PetscCall(FNCreate(PETSC_COMM_WORLD,&f3));
83: PetscCall(FNSetType(f3,FNEXP));
84: PetscCall(FNSetScale(f3,-tau,1.0));
86: funs[0] = f1;
87: funs[1] = f2;
88: funs[2] = f3;
89: PetscCall(DSNEPSetFN(ds,3,funs));
91: /* Set dimensions */
92: ld = n;
93: PetscCall(DSAllocate(ds,ld));
94: PetscCall(DSSetDimensions(ds,n,0,0));
96: /* Set up viewer */
97: PetscCall(PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer));
98: PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL));
99: PetscCall(PetscViewerPopFormat(viewer));
100: if (verbose) PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB));
102: /* Fill matrices */
103: PetscCall(DSGetArray(ds,DS_MAT_E0,&Id));
104: for (i=0;i<n;i++) Id[i+i*ld]=1.0;
105: PetscCall(DSRestoreArray(ds,DS_MAT_E0,&Id));
106: h = PETSC_PI/(PetscReal)(n+1);
107: PetscCall(DSGetArray(ds,DS_MAT_E1,&A));
108: for (i=0;i<n;i++) A[i+i*ld]=-2.0/(h*h)+a;
109: for (i=1;i<n;i++) {
110: A[i+(i-1)*ld]=1.0/(h*h);
111: A[(i-1)+i*ld]=1.0/(h*h);
112: }
113: PetscCall(DSRestoreArray(ds,DS_MAT_E1,&A));
114: PetscCall(DSGetArray(ds,DS_MAT_E2,&B));
115: for (i=0;i<n;i++) {
116: xi = (i+1)*h;
117: B[i+i*ld] = -4.1+xi*(1.0-PetscExpReal(xi-PETSC_PI));
118: }
119: PetscCall(DSRestoreArray(ds,DS_MAT_E2,&B));
121: if (verbose) {
122: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n"));
123: PetscCall(DSView(ds,viewer));
124: }
126: /* Solve */
127: PetscCall(PetscCalloc2(n,&wr,n,&wi));
128: PetscCall(DSGetSlepcSC(ds,&sc));
129: sc->comparison = SlepcCompareLargestMagnitude;
130: sc->comparisonctx = NULL;
131: sc->map = NULL;
132: sc->mapobj = NULL;
133: PetscCall(DSSolve(ds,wr,wi));
134: PetscCall(DSSort(ds,wr,wi,NULL,NULL,NULL));
136: if (verbose) {
137: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n"));
138: PetscCall(DSView(ds,viewer));
139: }
140: PetscCall(DSGetDimensions(ds,NULL,NULL,NULL,&nev));
142: /* Print computed eigenvalues */
143: PetscCall(DSNEPGetNumFN(ds,&nfun));
144: PetscCall(PetscMalloc1(ld*ld,&W));
145: PetscCall(DSVectors(ds,DS_MAT_X,NULL,NULL));
146: PetscCall(DSGetArray(ds,DS_MAT_X,&X));
147: PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n"));
148: for (i=0;i<nev;i++) {
149: #if defined(PETSC_USE_COMPLEX)
150: re = PetscRealPart(wr[i]);
151: im = PetscImaginaryPart(wr[i]);
152: #else
153: re = wr[i];
154: im = wi[i];
155: #endif
156: /* Residual */
157: PetscCall(PetscArrayzero(W,ld*ld));
158: for (k=0;k<nfun;k++) {
159: PetscCall(FNEvaluateFunction(funs[k],wr[i],&alpha));
160: PetscCall(DSGetArray(ds,mat[k],&A));
161: for (jj=0;jj<n;jj++) for (ii=0;ii<n;ii++) W[jj*ld+ii] += alpha*A[jj*ld+ii];
162: PetscCall(DSRestoreArray(ds,mat[k],&A));
163: }
164: nrm = 0.0;
165: for (k=0;k<n;k++) {
166: auxr = 0.0;
167: #if !defined(PETSC_USE_COMPLEX)
168: auxi = 0.0;
169: #endif
170: for (j=0;j<n;j++) {
171: auxr += W[k+j*ld]*X[i*ld+j];
172: #if !defined(PETSC_USE_COMPLEX)
173: if (PetscAbs(wi[j])!=0.0) auxi += W[k+j*ld]*X[(i+1)*ld+j];
174: #endif
175: }
176: aux = SlepcAbsEigenvalue(auxr,auxi);
177: nrm += aux*aux;
178: }
179: nrm = PetscSqrtReal(nrm);
180: if (nrm>1000*n*PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Warning: the residual norm of the %" PetscInt_FMT "-th computed eigenpair %g\n",i,(double)nrm));
181: if (PetscAbs(im)<1e-10) PetscCall(PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re));
182: else PetscCall(PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im));
183: }
184: PetscCall(PetscFree(W));
185: PetscCall(DSRestoreArray(ds,DS_MAT_X,&X));
186: PetscCall(DSRestoreArray(ds,DS_MAT_W,&W));
187: PetscCall(PetscFree2(wr,wi));
188: PetscCall(FNDestroy(&f1));
189: PetscCall(FNDestroy(&f2));
190: PetscCall(FNDestroy(&f3));
191: PetscCall(DSDestroy(&ds));
192: PetscCall(SlepcFinalize());
193: return 0;
194: }
196: /*TEST
198: testset:
199: test:
200: suffix: 1
201: requires: !complex
202: test:
203: suffix: 2
204: args: -ds_nep_rg_ellipse_radius 10
205: filter: sed -e "s/[+-]0\.0*i//g" | sed -e "s/37411/37410/"
206: requires: complex
208: TEST*/