Date: 2022-03-31T15:29:02+00:00

Actual source code: test9.c
slepc-3.17.0 2022-03-31
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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*/