Actual source code: ex50.c

slepc-3.20.1 2023-11-27
Report Typos and Errors
  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[] = "User-defined split preconditioner when solving a quadratic eigenproblem.\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 <slepcpep.h>

 18: int main(int argc,char **argv)
 19: {
 20:   Mat            A[3],P[3];      /* problem matrices and split preconditioner matrices */
 21:   PEP            pep;            /* polynomial eigenproblem solver context */
 22:   ST             st;
 23:   PetscInt       N,n=10,m,Istart,Iend,II,i,j;
 24:   PetscBool      flag,terse;

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

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

 35:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 36:      Compute the matrices for (k^2*A_2+k*A_1+A_0)x=0, and their approximations
 37:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 39:   /* A[0] is the 2-D Laplacian */
 40:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A[0]));
 41:   PetscCall(MatSetSizes(A[0],PETSC_DECIDE,PETSC_DECIDE,N,N));
 42:   PetscCall(MatSetFromOptions(A[0]));
 43:   PetscCall(MatSetUp(A[0]));
 44:   PetscCall(MatCreate(PETSC_COMM_WORLD,&P[0]));
 45:   PetscCall(MatSetSizes(P[0],PETSC_DECIDE,PETSC_DECIDE,N,N));
 46:   PetscCall(MatSetFromOptions(P[0]));
 47:   PetscCall(MatSetUp(P[0]));

 49:   PetscCall(MatGetOwnershipRange(A[0],&Istart,&Iend));
 50:   for (II=Istart;II<Iend;II++) {
 51:     i = II/n; j = II-i*n;
 52:     if (i>0) PetscCall(MatSetValue(A[0],II,II-n,-1.0,INSERT_VALUES));
 53:     if (i<m-1) PetscCall(MatSetValue(A[0],II,II+n,-1.0,INSERT_VALUES));
 54:     if (j>0) PetscCall(MatSetValue(A[0],II,II-1,-1.0,INSERT_VALUES));
 55:     if (j<n-1) PetscCall(MatSetValue(A[0],II,II+1,-1.0,INSERT_VALUES));
 56:     PetscCall(MatSetValue(A[0],II,II,4.0,INSERT_VALUES));
 57:     if (j>0) PetscCall(MatSetValue(P[0],II,II-1,-1.0,INSERT_VALUES));
 58:     if (j<n-1) PetscCall(MatSetValue(P[0],II,II+1,-1.0,INSERT_VALUES));
 59:     PetscCall(MatSetValue(P[0],II,II,4.0,INSERT_VALUES));
 60:   }
 61:   PetscCall(MatAssemblyBegin(A[0],MAT_FINAL_ASSEMBLY));
 62:   PetscCall(MatAssemblyEnd(A[0],MAT_FINAL_ASSEMBLY));
 63:   PetscCall(MatAssemblyBegin(P[0],MAT_FINAL_ASSEMBLY));
 64:   PetscCall(MatAssemblyEnd(P[0],MAT_FINAL_ASSEMBLY));

 66:   /* A[1] is the 1-D Laplacian on horizontal lines */
 67:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A[1]));
 68:   PetscCall(MatSetSizes(A[1],PETSC_DECIDE,PETSC_DECIDE,N,N));
 69:   PetscCall(MatSetFromOptions(A[1]));
 70:   PetscCall(MatSetUp(A[1]));
 71:   PetscCall(MatCreate(PETSC_COMM_WORLD,&P[1]));
 72:   PetscCall(MatSetSizes(P[1],PETSC_DECIDE,PETSC_DECIDE,N,N));
 73:   PetscCall(MatSetFromOptions(P[1]));
 74:   PetscCall(MatSetUp(P[1]));

 76:   PetscCall(MatGetOwnershipRange(A[1],&Istart,&Iend));
 77:   for (II=Istart;II<Iend;II++) {
 78:     i = II/n; j = II-i*n;
 79:     if (j>0) PetscCall(MatSetValue(A[1],II,II-1,-1.0,INSERT_VALUES));
 80:     if (j<n-1) PetscCall(MatSetValue(A[1],II,II+1,-1.0,INSERT_VALUES));
 81:     PetscCall(MatSetValue(A[1],II,II,2.0,INSERT_VALUES));
 82:     PetscCall(MatSetValue(P[1],II,II,2.0,INSERT_VALUES));
 83:   }
 84:   PetscCall(MatAssemblyBegin(A[1],MAT_FINAL_ASSEMBLY));
 85:   PetscCall(MatAssemblyEnd(A[1],MAT_FINAL_ASSEMBLY));
 86:   PetscCall(MatAssemblyBegin(P[1],MAT_FINAL_ASSEMBLY));
 87:   PetscCall(MatAssemblyEnd(P[1],MAT_FINAL_ASSEMBLY));

 89:   /* A[2] is a diagonal matrix */
 90:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A[2]));
 91:   PetscCall(MatSetSizes(A[2],PETSC_DECIDE,PETSC_DECIDE,N,N));
 92:   PetscCall(MatSetFromOptions(A[2]));
 93:   PetscCall(MatSetUp(A[2]));
 94:   PetscCall(MatCreate(PETSC_COMM_WORLD,&P[2]));
 95:   PetscCall(MatSetSizes(P[2],PETSC_DECIDE,PETSC_DECIDE,N,N));
 96:   PetscCall(MatSetFromOptions(P[2]));
 97:   PetscCall(MatSetUp(P[2]));

 99:   PetscCall(MatGetOwnershipRange(A[2],&Istart,&Iend));
100:   for (II=Istart;II<Iend;II++) {
101:     PetscCall(MatSetValue(A[2],II,II,(PetscReal)(II+1),INSERT_VALUES));
102:     PetscCall(MatSetValue(P[2],II,II,(PetscReal)(II+1),INSERT_VALUES));
103:   }
104:   PetscCall(MatAssemblyBegin(A[2],MAT_FINAL_ASSEMBLY));
105:   PetscCall(MatAssemblyEnd(A[2],MAT_FINAL_ASSEMBLY));
106:   PetscCall(MatAssemblyBegin(P[2],MAT_FINAL_ASSEMBLY));
107:   PetscCall(MatAssemblyEnd(P[2],MAT_FINAL_ASSEMBLY));

109:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
110:                 Create the eigensolver and set various options
111:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

113:   PetscCall(PEPCreate(PETSC_COMM_WORLD,&pep));
114:   PetscCall(PEPSetOperators(pep,3,A));
115:   PetscCall(PEPSetProblemType(pep,PEP_HERMITIAN));

117:   PetscCall(PEPGetST(pep,&st));
118:   PetscCall(STSetType(st,STSINVERT));
119:   PetscCall(STSetSplitPreconditioner(st,3,P,SUBSET_NONZERO_PATTERN));

121:   PetscCall(PEPSetTarget(pep,-2.0));
122:   PetscCall(PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE));

124:   /*
125:      Set solver parameters at runtime
126:   */
127:   PetscCall(PEPSetFromOptions(pep));

129:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
130:              Solve the eigensystem, display solution and clean up
131:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

133:   PetscCall(PEPSolve(pep));
134:   /* show detailed info unless -terse option is given by user */
135:   PetscCall(PetscOptionsHasName(NULL,NULL,"-terse",&terse));
136:   if (terse) PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,NULL));
137:   else {
138:     PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL));
139:     PetscCall(PEPConvergedReasonView(pep,PETSC_VIEWER_STDOUT_WORLD));
140:     PetscCall(PEPErrorView(pep,PEP_ERROR_BACKWARD,PETSC_VIEWER_STDOUT_WORLD));
141:     PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
142:   }
143:   PetscCall(PEPDestroy(&pep));
144:   PetscCall(MatDestroy(&A[0]));
145:   PetscCall(MatDestroy(&A[1]));
146:   PetscCall(MatDestroy(&A[2]));
147:   PetscCall(MatDestroy(&P[0]));
148:   PetscCall(MatDestroy(&P[1]));
149:   PetscCall(MatDestroy(&P[2]));
150:   PetscCall(SlepcFinalize());
151:   return 0;
152: }

154: /*TEST

156:    testset:
157:       args: -pep_nev 4 -pep_ncv 28 -n 12 -terse
158:       output_file: output/ex50_1.out
159:       requires: double
160:       test:
161:          suffix: 1
162:          args: -pep_type {{toar qarnoldi}}
163:       test:
164:          suffix: 1_linear
165:          args: -pep_type linear -pep_general

167:    testset:
168:       args: -pep_all -n 12 -pep_type ciss -rg_type ellipse -rg_ellipse_center -1+1.5i -rg_ellipse_radius .3 -terse
169:       output_file: output/ex50_2.out
170:       requires: complex double
171:       timeoutfactor: 2
172:       test:
173:          suffix: 2
174:       test:
175:          suffix: 2_par
176:          nsize: 2
177:          args: -pep_ciss_partitions 2

179: TEST*/