Actual source code: test23.c

slepc-3.18.2 2023-01-26
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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

 34:   SlepcInitialize(&argc,&argv,(char*)0,help);
 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 %" PetscInt_FMT ", 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)
 58:   RGIsTrivial(rg,&flg);
 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 %" PetscInt_FMT " integration points, minimality index %" PetscInt_FMT ", and sampling size %" PetscInt_FMT "\n",ip,midx,spls);
 68:     if (rits) PetscPrintf(PETSC_COMM_WORLD,"Doing %" PetscInt_FMT " iterations of Newton refinement\n",rits);
 69:   }

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

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

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

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

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

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

102:   /* Fill matrices */
103:   DSGetArray(ds,DS_MAT_E0,&Id);
104:   for (i=0;i<n;i++) Id[i+i*ld]=1.0;
105:   DSRestoreArray(ds,DS_MAT_E0,&Id);
106:   h = PETSC_PI/(PetscReal)(n+1);
107:   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:   DSRestoreArray(ds,DS_MAT_E1,&A);
114:   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:   DSRestoreArray(ds,DS_MAT_E2,&B);

121:   if (verbose) {
122:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
123:     DSView(ds,viewer);
124:   }

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

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

142:   /* Print computed eigenvalues */
143:   DSNEPGetNumFN(ds,&nfun);
144:   PetscMalloc1(ld*ld,&W);
145:   DSVectors(ds,DS_MAT_X,NULL,NULL);
146:   DSGetArray(ds,DS_MAT_X,&X);
147:   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:     PetscArrayzero(W,ld*ld);
158:     for (k=0;k<nfun;k++) {
159:       FNEvaluateFunction(funs[k],wr[i],&alpha);
160:       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:       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) 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) PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
182:     else PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
183:   }
184:   PetscFree(W);
185:   DSRestoreArray(ds,DS_MAT_X,&X);
186:   DSRestoreArray(ds,DS_MAT_W,&W);
187:   PetscFree2(wr,wi);
188:   FNDestroy(&f1);
189:   FNDestroy(&f2);
190:   FNDestroy(&f3);
191:   DSDestroy(&ds);
192:   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*/