Actual source code: ex2.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[] = "Standard symmetric eigenproblem corresponding to the Laplacian operator in 2 dimensions.\n\n"
 12:   "The command line options are:\n"
 13:   "  -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
 14:   "  -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";

 16: #include <slepceps.h>

 18: int main(int argc,char **argv)
 19: {
 20:   Mat            A;               /* operator matrix */
 21:   EPS            eps;             /* eigenproblem solver context */
 22:   EPSType        type;
 23:   PetscInt       N,n=10,m,Istart,Iend,II,nev,i,j;
 24:   PetscBool      flag,terse;

 26:   SlepcInitialize(&argc,&argv,(char*)0,help);

 28:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 29:   PetscOptionsGetInt(NULL,NULL,"-m",&m,&flag);
 30:   if (!flag) m=n;
 31:   N = n*m;
 32:   PetscPrintf(PETSC_COMM_WORLD,"\n2-D Laplacian Eigenproblem, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m);

 34:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 35:      Compute the operator matrix that defines the eigensystem, Ax=kx
 36:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 38:   MatCreate(PETSC_COMM_WORLD,&A);
 39:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);
 40:   MatSetFromOptions(A);
 41:   MatSetUp(A);

 43:   MatGetOwnershipRange(A,&Istart,&Iend);
 44:   for (II=Istart;II<Iend;II++) {
 45:     i = II/n; j = II-i*n;
 46:     if (i>0) MatSetValue(A,II,II-n,-1.0,INSERT_VALUES);
 47:     if (i<m-1) MatSetValue(A,II,II+n,-1.0,INSERT_VALUES);
 48:     if (j>0) MatSetValue(A,II,II-1,-1.0,INSERT_VALUES);
 49:     if (j<n-1) MatSetValue(A,II,II+1,-1.0,INSERT_VALUES);
 50:     MatSetValue(A,II,II,4.0,INSERT_VALUES);
 51:   }

 53:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 54:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

 56:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 57:                 Create the eigensolver and set various options
 58:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 60:   /*
 61:      Create eigensolver context
 62:   */
 63:   EPSCreate(PETSC_COMM_WORLD,&eps);

 65:   /*
 66:      Set operators. In this case, it is a standard eigenvalue problem
 67:   */
 68:   EPSSetOperators(eps,A,NULL);
 69:   EPSSetProblemType(eps,EPS_HEP);

 71:   /*
 72:      Set solver parameters at runtime
 73:   */
 74:   EPSSetFromOptions(eps);

 76:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 77:                       Solve the eigensystem
 78:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 80:   EPSSolve(eps);

 82:   /*
 83:      Optional: Get some information from the solver and display it
 84:   */
 85:   EPSGetType(eps,&type);
 86:   PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type);
 87:   EPSGetDimensions(eps,&nev,NULL,NULL);
 88:   PetscPrintf(PETSC_COMM_WORLD," Number of requested eigenvalues: %" PetscInt_FMT "\n",nev);

 90:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 91:                     Display solution and clean up
 92:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 94:   /* show detailed info unless -terse option is given by user */
 95:   PetscOptionsHasName(NULL,NULL,"-terse",&terse);
 96:   if (terse) EPSErrorView(eps,EPS_ERROR_RELATIVE,NULL);
 97:   else {
 98:     PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
 99:     EPSConvergedReasonView(eps,PETSC_VIEWER_STDOUT_WORLD);
100:     EPSErrorView(eps,EPS_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
101:     PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
102:   }
103:   EPSDestroy(&eps);
104:   MatDestroy(&A);
105:   SlepcFinalize();
106:   return 0;
107: }

109: /*TEST

111:    testset:
112:       args: -n 72 -eps_nev 4 -eps_ncv 20 -terse
113:       output_file: output/ex2_1.out
114:       requires: !single
115:       test:
116:          suffix: 1
117:       test:
118:          suffix: 2
119:          args: -library_preload

121:    testset:
122:       args: -n 30 -eps_type ciss -eps_ciss_realmats -terse
123:       requires: !single
124:       output_file: output/ex2_ciss.out
125:       filter: grep -v method
126:       test:
127:          suffix: ciss_1
128:          nsize: 1
129:          args: -rg_type interval -rg_interval_endpoints 1.1,1.25,-.1,.1
130:          requires: complex
131:       test:
132:          suffix: ciss_1_hpddm
133:          nsize: 1
134:          args: -rg_type interval -rg_interval_endpoints 1.1,1.25 -st_ksp_type hpddm
135:          requires: hpddm
136:       test:
137:          suffix: ciss_2
138:          nsize: 2
139:          args: -rg_type ellipse -rg_ellipse_center 1.175 -rg_ellipse_radius 0.075 -eps_ciss_partitions 2
140:       test:
141:          suffix: ciss_2_block
142:          args: -rg_type ellipse -rg_ellipse_center 1.175 -rg_ellipse_radius 0.075 -eps_ciss_blocksize 3 -eps_ciss_moments 2
143:          requires: complex !__float128
144:       test:
145:          suffix: ciss_2_hpddm
146:          nsize: 2
147:          args: -rg_type ellipse -rg_ellipse_center 1.175 -rg_ellipse_radius 0.075 -eps_ciss_partitions 2 -eps_ciss_ksp_type hpddm
148:          requires: hpddm
149:       test:
150:          suffix: feast
151:          args: -eps_type feast -eps_interval 1.1,1.25 -eps_ncv 64
152:          requires: feast

154:    testset:
155:       args: -n 30 -m 30 -eps_interval 3.9,4.15 -terse
156:       output_file: output/ex2_3.out
157:       filter: grep -v Solution
158:       requires: !single
159:       test:
160:          suffix: 3
161:          args: -st_type sinvert -st_pc_type cholesky
162:       test:
163:          suffix: 3_evsl
164:          args: -eps_type evsl -eps_evsl_slices 6
165:          requires: evsl

167:    testset:
168:       args: -n 45 -m 46 -eps_interval 4.54,4.57 -eps_ncv 24 -terse
169:       output_file: output/ex2_4.out
170:       filter: grep -v Solution
171:       requires: !single
172:       timeoutfactor: 2
173:       test:
174:          suffix: 4
175:          args: -st_type sinvert -st_pc_type cholesky
176:       test:
177:          suffix: 4_filter
178:          args: -eps_type {{krylovschur subspace}} -st_type filter -st_filter_degree 200
179:          requires: !__float128
180:       test:
181:          suffix: 4_filter_cuda
182:          args: -eps_type {{krylovschur subspace}} -st_type filter -st_filter_degree 200 -mat_type aijcusparse
183:          requires: cuda
184:       test:
185:          suffix: 4_evsl
186:          args: -eps_type evsl
187:          requires: evsl

189: TEST*/