Actual source code: test23.c

slepc-3.17.2 2022-08-09
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  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:   SlepcInitialize(&argc,&argv,(char*)0,help);
 34:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 35:   PetscOptionsGetReal(NULL,NULL,"-tau",&tau,NULL);
 36:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NEP - dimension %" PetscInt_FMT ", tau=%g.\n",n,(double)tau);
 37:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);

 39:   /* Create DS object and set options */
 40:   DSCreate(PETSC_COMM_WORLD,&ds);
 41:   DSSetType(ds,DSNEP);
 42: #if defined(PETSC_USE_COMPLEX)
 43:   DSSetMethod(ds,1);  /* contour integral */
 44: #endif
 45:   DSNEPGetRG(ds,&rg);
 46:   RGSetType(rg,RGELLIPSE);
 47:   DSNEPSetMinimality(ds,1);
 48:   DSNEPSetIntegrationPoints(ds,16);
 49:   DSNEPSetRefine(ds,PETSC_DEFAULT,2);
 50:   DSNEPSetSamplingSize(ds,25);
 51:   DSSetFromOptions(ds);

 53:   /* Print current options */
 54:   DSGetMethod(ds,&meth);
 55: #if defined(PETSC_USE_COMPLEX)
 57:   RGIsTrivial(rg,&flg);
 59: #endif

 61:   DSNEPGetMinimality(ds,&midx);
 62:   DSNEPGetIntegrationPoints(ds,&ip);
 63:   DSNEPGetRefine(ds,NULL,&rits);
 64:   DSNEPGetSamplingSize(ds,&spls);
 65:   if (meth==1) {
 66:     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);
 67:     if (rits) PetscPrintf(PETSC_COMM_WORLD,"Doing %" PetscInt_FMT " iterations of Newton refinement\n",rits);
 68:   }

 70:   /* Set functions (prior to DSAllocate) */
 71:   FNCreate(PETSC_COMM_WORLD,&f1);
 72:   FNSetType(f1,FNRATIONAL);
 73:   coeffs[0] = -1.0; coeffs[1] = 0.0;
 74:   FNRationalSetNumerator(f1,2,coeffs);

 76:   FNCreate(PETSC_COMM_WORLD,&f2);
 77:   FNSetType(f2,FNRATIONAL);
 78:   coeffs[0] = 1.0;
 79:   FNRationalSetNumerator(f2,1,coeffs);

 81:   FNCreate(PETSC_COMM_WORLD,&f3);
 82:   FNSetType(f3,FNEXP);
 83:   FNSetScale(f3,-tau,1.0);

 85:   funs[0] = f1;
 86:   funs[1] = f2;
 87:   funs[2] = f3;
 88:   DSNEPSetFN(ds,3,funs);

 90:   /* Set dimensions */
 91:   ld = n;
 92:   DSAllocate(ds,ld);
 93:   DSSetDimensions(ds,n,0,0);

 95:   /* Set up viewer */
 96:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
 97:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
 98:   PetscViewerPopFormat(viewer);
 99:   if (verbose) PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);

101:   /* Fill matrices */
102:   DSGetArray(ds,DS_MAT_E0,&Id);
103:   for (i=0;i<n;i++) Id[i+i*ld]=1.0;
104:   DSRestoreArray(ds,DS_MAT_E0,&Id);
105:   h = PETSC_PI/(PetscReal)(n+1);
106:   DSGetArray(ds,DS_MAT_E1,&A);
107:   for (i=0;i<n;i++) A[i+i*ld]=-2.0/(h*h)+a;
108:   for (i=1;i<n;i++) {
109:     A[i+(i-1)*ld]=1.0/(h*h);
110:     A[(i-1)+i*ld]=1.0/(h*h);
111:   }
112:   DSRestoreArray(ds,DS_MAT_E1,&A);
113:   DSGetArray(ds,DS_MAT_E2,&B);
114:   for (i=0;i<n;i++) {
115:     xi = (i+1)*h;
116:     B[i+i*ld] = -4.1+xi*(1.0-PetscExpReal(xi-PETSC_PI));
117:   }
118:   DSRestoreArray(ds,DS_MAT_E2,&B);

120:   if (verbose) {
121:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
122:     DSView(ds,viewer);
123:   }

125:   /* Solve */
126:   PetscCalloc2(n,&wr,n,&wi);
127:   DSGetSlepcSC(ds,&sc);
128:   sc->comparison    = SlepcCompareLargestMagnitude;
129:   sc->comparisonctx = NULL;
130:   sc->map           = NULL;
131:   sc->mapobj        = NULL;
132:   DSSolve(ds,wr,wi);
133:   DSSort(ds,wr,wi,NULL,NULL,NULL);

135:   if (verbose) {
136:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
137:     DSView(ds,viewer);
138:   }
139:   DSGetDimensions(ds,NULL,NULL,NULL,&nev);

141:   /* Print computed eigenvalues */
142:   DSNEPGetNumFN(ds,&nfun);
143:   PetscMalloc1(ld*ld,&W);
144:   DSVectors(ds,DS_MAT_X,NULL,NULL);
145:   DSGetArray(ds,DS_MAT_X,&X);
146:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
147:   for (i=0;i<nev;i++) {
148: #if defined(PETSC_USE_COMPLEX)
149:     re = PetscRealPart(wr[i]);
150:     im = PetscImaginaryPart(wr[i]);
151: #else
152:     re = wr[i];
153:     im = wi[i];
154: #endif
155:     /* Residual */
156:     PetscArrayzero(W,ld*ld);
157:     for (k=0;k<nfun;k++) {
158:       FNEvaluateFunction(funs[k],wr[i],&alpha);
159:       DSGetArray(ds,mat[k],&A);
160:       for (jj=0;jj<n;jj++) for (ii=0;ii<n;ii++) W[jj*ld+ii] += alpha*A[jj*ld+ii];
161:       DSRestoreArray(ds,mat[k],&A);
162:     }
163:     nrm = 0.0;
164:     for (k=0;k<n;k++) {
165:       auxr = 0.0;
166: #if !defined(PETSC_USE_COMPLEX)
167:       auxi = 0.0;
168: #endif
169:       for (j=0;j<n;j++) {
170:         auxr += W[k+j*ld]*X[i*ld+j];
171: #if !defined(PETSC_USE_COMPLEX)
172:         if (PetscAbs(wi[j])!=0.0) auxi += W[k+j*ld]*X[(i+1)*ld+j];
173: #endif
174:       }
175:       aux = SlepcAbsEigenvalue(auxr,auxi);
176:       nrm += aux*aux;
177:     }
178:     nrm = PetscSqrtReal(nrm);
179:     if (nrm>1000*n*PETSC_MACHINE_EPSILON) PetscPrintf(PETSC_COMM_WORLD,"Warning: the residual norm of the %" PetscInt_FMT "-th computed eigenpair %g\n",i,(double)nrm);
180:     if (PetscAbs(im)<1e-10) PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
181:     else PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
182:   }
183:   PetscFree(W);
184:   DSRestoreArray(ds,DS_MAT_X,&X);
185:   DSRestoreArray(ds,DS_MAT_W,&W);
186:   PetscFree2(wr,wi);
187:   FNDestroy(&f1);
188:   FNDestroy(&f2);
189:   FNDestroy(&f3);
190:   DSDestroy(&ds);
191:   SlepcFinalize();
192:   return 0;
193: }

195: /*TEST

197:    testset:
198:       test:
199:          suffix: 1
200:          requires: !complex
201:       test:
202:          suffix: 2
203:          args: -ds_nep_rg_ellipse_radius 10
204:          filter: sed -e "s/[+-]0\.0*i//g" | sed -e "s/37411/37410/"
205:          requires: complex

207: TEST*/