Actual source code: test9.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 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;

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

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

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

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

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

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

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

 78:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 79:      Compute the split preconditioner matrices (four diagonals)
 80:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

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

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

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

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

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

119:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
120:                 Create the spectral transformation object
121:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

141:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
142:                    Apply the operator
143:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

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

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

179: /*TEST

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

186: TEST*/