Actual source code: test9.c

slepc-3.18.1 2022-11-02
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[] = "Test ST with four matrices and split preconditioner.\n\n";

 13: #include <slepcst.h>

 15: int main(int argc,char **argv)
 16: {
 17:   Mat            A,B,C,D,Pa,Pb,Pc,Pd,Pmat,mat[4];
 18:   ST             st;
 19:   KSP            ksp;
 20:   PC             pc;
 21:   Vec            v,w;
 22:   STType         type;
 23:   PetscScalar    sigma;
 24:   PetscInt       n=10,i,Istart,Iend;

 27:   SlepcInitialize(&argc,&argv,(char*)0,help);
 28:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 29:   PetscPrintf(PETSC_COMM_WORLD,"\nTest ST with four matrices, n=%" PetscInt_FMT "\n\n",n);
 30:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 31:      Compute the operator matrices
 32:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 34:   MatCreate(PETSC_COMM_WORLD,&A);
 35:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
 36:   MatSetFromOptions(A);
 37:   MatSetUp(A);

 39:   MatCreate(PETSC_COMM_WORLD,&B);
 40:   MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,n,n);
 41:   MatSetFromOptions(B);
 42:   MatSetUp(B);

 44:   MatCreate(PETSC_COMM_WORLD,&C);
 45:   MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,n,n);
 46:   MatSetFromOptions(C);
 47:   MatSetUp(C);

 49:   MatCreate(PETSC_COMM_WORLD,&D);
 50:   MatSetSizes(D,PETSC_DECIDE,PETSC_DECIDE,n,n);
 51:   MatSetFromOptions(D);
 52:   MatSetUp(D);

 54:   MatGetOwnershipRange(A,&Istart,&Iend);
 55:   for (i=Istart;i<Iend;i++) {
 56:     MatSetValue(A,i,i,2.0,INSERT_VALUES);
 57:     if (i>0) {
 58:       MatSetValue(A,i,i-1,-1.0,INSERT_VALUES);
 59:       MatSetValue(B,i,i,(PetscScalar)i,INSERT_VALUES);
 60:     } else MatSetValue(B,i,i,-1.0,INSERT_VALUES);
 61:     if (i<n-1) MatSetValue(A,i,i+1,-1.0,INSERT_VALUES);
 62:     MatSetValue(C,i,n-i-1,1.0,INSERT_VALUES);
 63:     MatSetValue(D,i,i,i*.1,INSERT_VALUES);
 64:     if (i==0) MatSetValue(D,0,n-1,1.0,INSERT_VALUES);
 65:     if (i==n-1) MatSetValue(D,n-1,0,1.0,INSERT_VALUES);
 66:   }

 68:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
 69:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
 70:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
 71:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
 72:   MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
 73:   MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
 74:   MatAssemblyBegin(D,MAT_FINAL_ASSEMBLY);
 75:   MatAssemblyEnd(D,MAT_FINAL_ASSEMBLY);
 76:   MatCreateVecs(A,&v,&w);
 77:   VecSet(v,1.0);

 79:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 80:      Compute the split preconditioner matrices (four diagonals)
 81:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 83:   MatCreate(PETSC_COMM_WORLD,&Pa);
 84:   MatSetSizes(Pa,PETSC_DECIDE,PETSC_DECIDE,n,n);
 85:   MatSetFromOptions(Pa);
 86:   MatSetUp(Pa);

 88:   MatCreate(PETSC_COMM_WORLD,&Pb);
 89:   MatSetSizes(Pb,PETSC_DECIDE,PETSC_DECIDE,n,n);
 90:   MatSetFromOptions(Pb);
 91:   MatSetUp(Pb);

 93:   MatCreate(PETSC_COMM_WORLD,&Pc);
 94:   MatSetSizes(Pc,PETSC_DECIDE,PETSC_DECIDE,n,n);
 95:   MatSetFromOptions(Pc);
 96:   MatSetUp(Pc);

 98:   MatCreate(PETSC_COMM_WORLD,&Pd);
 99:   MatSetSizes(Pd,PETSC_DECIDE,PETSC_DECIDE,n,n);
100:   MatSetFromOptions(Pd);
101:   MatSetUp(Pd);

103:   MatGetOwnershipRange(Pa,&Istart,&Iend);
104:   for (i=Istart;i<Iend;i++) {
105:     MatSetValue(Pa,i,i,2.0,INSERT_VALUES);
106:     if (i>0) MatSetValue(Pb,i,i,(PetscScalar)i,INSERT_VALUES);
107:     else MatSetValue(Pb,i,i,-1.0,INSERT_VALUES);
108:     MatSetValue(Pd,i,i,i*.1,INSERT_VALUES);
109:   }

111:   MatAssemblyBegin(Pa,MAT_FINAL_ASSEMBLY);
112:   MatAssemblyEnd(Pa,MAT_FINAL_ASSEMBLY);
113:   MatAssemblyBegin(Pb,MAT_FINAL_ASSEMBLY);
114:   MatAssemblyEnd(Pb,MAT_FINAL_ASSEMBLY);
115:   MatAssemblyBegin(Pc,MAT_FINAL_ASSEMBLY);
116:   MatAssemblyEnd(Pc,MAT_FINAL_ASSEMBLY);
117:   MatAssemblyBegin(Pd,MAT_FINAL_ASSEMBLY);
118:   MatAssemblyEnd(Pd,MAT_FINAL_ASSEMBLY);

120:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
121:                 Create the spectral transformation object
122:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

124:   STCreate(PETSC_COMM_WORLD,&st);
125:   mat[0] = A;
126:   mat[1] = B;
127:   mat[2] = C;
128:   mat[3] = D;
129:   STSetMatrices(st,4,mat);
130:   mat[0] = Pa;
131:   mat[1] = Pb;
132:   mat[2] = Pc;
133:   mat[3] = Pd;
134:   STSetSplitPreconditioner(st,4,mat,SUBSET_NONZERO_PATTERN);
135:   STGetKSP(st,&ksp);
136:   KSPSetTolerances(ksp,100*PETSC_MACHINE_EPSILON,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
137:   STSetTransform(st,PETSC_TRUE);
138:   STSetFromOptions(st);
139:   STGetKSP(st,&ksp);
140:   KSPGetPC(ksp,&pc);

142:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
143:                    Apply the operator
144:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

146:   /* sigma=0.0 */
147:   STSetUp(st);
148:   STGetType(st,&type);
149:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
150:   PCGetOperators(pc,NULL,&Pmat);
151:   MatView(Pmat,NULL);
152:   STMatSolve(st,v,w);
153:   VecView(w,NULL);

155:   /* sigma=0.1 */
156:   sigma = 0.1;
157:   STSetShift(st,sigma);
158:   STGetShift(st,&sigma);
159:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
160:   PCGetOperators(pc,NULL,&Pmat);
161:   MatView(Pmat,NULL);
162:   STMatSolve(st,v,w);
163:   VecView(w,NULL);

165:   STDestroy(&st);
166:   MatDestroy(&A);
167:   MatDestroy(&B);
168:   MatDestroy(&C);
169:   MatDestroy(&D);
170:   MatDestroy(&Pa);
171:   MatDestroy(&Pb);
172:   MatDestroy(&Pc);
173:   MatDestroy(&Pd);
174:   VecDestroy(&v);
175:   VecDestroy(&w);
176:   SlepcFinalize();
177:   return 0;
178: }

180: /*TEST

182:    test:
183:       suffix: 1
184:       args: -st_type {{shift sinvert}separate output} -st_pc_type jacobi
185:       requires: !single

187: TEST*/