Actual source code: test23.c
slepc-3.16.0 2021-09-30
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-2021, 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: {
18: DS ds;
19: FN f1,f2,f3,funs[3];
20: SlepcSC sc;
21: PetscScalar *Id,*A,*B,*wr,*wi,*X,*W,coeffs[2],auxr,alpha;
22: PetscReal tau=0.001,h,a=20,xi,re,im,nrm,aux;
23: PetscInt i,j,ii,jj,k,n=10,ld,nev,nfun,midx,ip,rits,meth,spls;
24: PetscViewer viewer;
25: PetscBool verbose;
26: RG rg;
27: DSMatType mat[3]={DS_MAT_E0,DS_MAT_E1,DS_MAT_E2};
28: #if defined(PETSC_USE_COMPLEX)
29: PetscBool flg;
30: #else
31: PetscScalar auxi;
32: #endif
34: SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
35: PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
36: PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL);
37: PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NEP - dimension %D, tau=%g.\n",n,(double)tau);
38: PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);
40: /* Create DS object and set options */
41: DSCreate(PETSC_COMM_WORLD,&ds);
42: DSSetType(ds,DSNEP);
43: #if defined(PETSC_USE_COMPLEX)
44: DSSetMethod(ds,1); /* contour integral */
45: #endif
46: DSNEPGetRG(ds,&rg);
47: RGSetType(rg,RGELLIPSE);
48: DSNEPSetMinimality(ds,1);
49: DSNEPSetIntegrationPoints(ds,16);
50: DSNEPSetRefine(ds,PETSC_DEFAULT,2);
51: DSNEPSetSamplingSize(ds,25);
52: DSSetFromOptions(ds);
54: /* Print current options */
55: DSGetMethod(ds,&meth);
56: #if defined(PETSC_USE_COMPLEX)
57: if (meth!=1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"This example requires ds_method=1");
58: RGIsTrivial(rg,&flg);
59: if (flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Must at least set the radius of the ellipse");
60: #endif
62: DSNEPGetMinimality(ds,&midx);
63: DSNEPGetIntegrationPoints(ds,&ip);
64: DSNEPGetRefine(ds,NULL,&rits);
65: DSNEPGetSamplingSize(ds,&spls);
66: if (meth==1) {
67: PetscPrintf(PETSC_COMM_WORLD,"Contour integral method with %D integration points, minimality index %D, and sampling size %D\n",ip,midx,spls);
68: if (rits) {
69: PetscPrintf(PETSC_COMM_WORLD,"Doing %D iterations of Newton refinement\n",rits);
70: }
71: }
73: /* Set functions (prior to DSAllocate) */
74: FNCreate(PETSC_COMM_WORLD,&f1);
75: FNSetType(f1,FNRATIONAL);
76: coeffs[0] = -1.0; coeffs[1] = 0.0;
77: FNRationalSetNumerator(f1,2,coeffs);
79: FNCreate(PETSC_COMM_WORLD,&f2);
80: FNSetType(f2,FNRATIONAL);
81: coeffs[0] = 1.0;
82: FNRationalSetNumerator(f2,1,coeffs);
84: FNCreate(PETSC_COMM_WORLD,&f3);
85: FNSetType(f3,FNEXP);
86: FNSetScale(f3,-tau,1.0);
88: funs[0] = f1;
89: funs[1] = f2;
90: funs[2] = f3;
91: DSNEPSetFN(ds,3,funs);
93: /* Set dimensions */
94: ld = n;
95: DSAllocate(ds,ld);
96: DSSetDimensions(ds,n,0,0);
98: /* Set up viewer */
99: PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
100: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
101: PetscViewerPopFormat(viewer);
102: if (verbose) {
103: PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
104: }
106: /* Fill matrices */
107: DSGetArray(ds,DS_MAT_E0,&Id);
108: for (i=0;i<n;i++) Id[i+i*ld]=1.0;
109: DSRestoreArray(ds,DS_MAT_E0,&Id);
110: h = PETSC_PI/(PetscReal)(n+1);
111: DSGetArray(ds,DS_MAT_E1,&A);
112: for (i=0;i<n;i++) A[i+i*ld]=-2.0/(h*h)+a;
113: for (i=1;i<n;i++) {
114: A[i+(i-1)*ld]=1.0/(h*h);
115: A[(i-1)+i*ld]=1.0/(h*h);
116: }
117: DSRestoreArray(ds,DS_MAT_E1,&A);
118: DSGetArray(ds,DS_MAT_E2,&B);
119: for (i=0;i<n;i++) {
120: xi = (i+1)*h;
121: B[i+i*ld] = -4.1+xi*(1.0-PetscExpReal(xi-PETSC_PI));
122: }
123: DSRestoreArray(ds,DS_MAT_E2,&B);
125: if (verbose) {
126: PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
127: DSView(ds,viewer);
128: }
130: /* Solve */
131: PetscCalloc2(n,&wr,n,&wi);
132: DSGetSlepcSC(ds,&sc);
133: sc->comparison = SlepcCompareLargestMagnitude;
134: sc->comparisonctx = NULL;
135: sc->map = NULL;
136: sc->mapobj = NULL;
137: DSSolve(ds,wr,wi);
138: DSSort(ds,wr,wi,NULL,NULL,NULL);
140: if (verbose) {
141: PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
142: DSView(ds,viewer);
143: }
144: DSGetDimensions(ds,NULL,NULL,NULL,&nev);
146: /* Print computed eigenvalues */
147: DSNEPGetNumFN(ds,&nfun);
148: PetscMalloc1(ld*ld,&W);
149: DSVectors(ds,DS_MAT_X,NULL,NULL);
150: DSGetArray(ds,DS_MAT_X,&X);
151: PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
152: for (i=0;i<nev;i++) {
153: #if defined(PETSC_USE_COMPLEX)
154: re = PetscRealPart(wr[i]);
155: im = PetscImaginaryPart(wr[i]);
156: #else
157: re = wr[i];
158: im = wi[i];
159: #endif
160: /* Residual */
161: PetscArrayzero(W,ld*ld);
162: for (k=0;k<nfun;k++) {
163: FNEvaluateFunction(funs[k],wr[i],&alpha);
164: DSGetArray(ds,mat[k],&A);
165: for (jj=0;jj<n;jj++) for (ii=0;ii<n;ii++) W[jj*ld+ii] += alpha*A[jj*ld+ii];
166: DSRestoreArray(ds,mat[k],&A);
167: }
168: nrm = 0.0;
169: for (k=0;k<n;k++) {
170: auxr = 0.0;
171: #if !defined(PETSC_USE_COMPLEX)
172: auxi = 0.0;
173: #endif
174: for (j=0;j<n;j++) {
175: auxr += W[k+j*ld]*X[i*ld+j];
176: #if !defined(PETSC_USE_COMPLEX)
177: if (PetscAbs(wi[j])!=0.0) auxi += W[k+j*ld]*X[(i+1)*ld+j];
178: #endif
179: }
180: aux = SlepcAbsEigenvalue(auxr,auxi);
181: nrm += aux*aux;
182: }
183: nrm = PetscSqrtReal(nrm);
184: if (nrm>1000*n*PETSC_MACHINE_EPSILON) {
185: PetscPrintf(PETSC_COMM_WORLD,"Warning: the residual norm of the %D-th computed eigenpair %g\n",i,(double)nrm);
186: }
187: if (PetscAbs(im)<1e-10) {
188: PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re);
189: } else {
190: PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im);
191: }
192: }
193: PetscFree(W);
194: DSRestoreArray(ds,DS_MAT_X,&X);
195: DSRestoreArray(ds,DS_MAT_W,&W);
196: PetscFree2(wr,wi);
197: FNDestroy(&f1);
198: FNDestroy(&f2);
199: FNDestroy(&f3);
200: DSDestroy(&ds);
201: SlepcFinalize();
202: return ierr;
203: }
205: /*TEST
207: testset:
208: test:
209: suffix: 1
210: requires: !complex
211: test:
212: suffix: 2
213: args: -ds_nep_rg_ellipse_radius 10
214: filter: sed -e "s/[+-]0\.0*i//g" | sed -e "s/37411/37410/"
215: requires: complex
217: TEST*/