Actual source code: ex9.c

petsc-dev 2014-07-25
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  2: static char help[] = "Tests MatCreateComposite()\n\n";

  4: /*T
  5:    Concepts: Mat^composite matrices
  6:    Processors: n
  7: T*/

  9: /*
 10:   Include "petscmat.h" so that we can use matrices.
 11:   automatically includes:
 12:      petscsys.h       - base PETSc routines   petscvec.h    - vectors
 13:      petscmat.h    - matrices
 14:      petscis.h     - index sets            petscviewer.h - viewers
 15: */
 16: #include <petscmat.h>

 20: int main(int argc,char **args)
 21: {
 22:   Mat            A[3],B;                       /* matrix */
 23:   PetscViewer    fd;                      /* viewer */
 24:   char           file[PETSC_MAX_PATH_LEN];            /* input file name */
 26:   PetscBool      flg;
 27:   Vec            x,y,z,work;
 28:   PetscReal      rnorm;

 30:   PetscInitialize(&argc,&args,(char*)0,help);


 33:   /*
 34:      Determine files from which we read the two linear systems
 35:      (matrix and right-hand-side vector).
 36:   */
 37:   PetscOptionsGetString(NULL,"-f",file,PETSC_MAX_PATH_LEN,&flg);
 38:   if (!flg) SETERRQ(PETSC_COMM_WORLD,1,"Must indicate binary file with the -f option");

 40:   /*
 41:      Open binary file.  Note that we use FILE_MODE_READ to indicate
 42:      reading from this file.
 43:   */
 44:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);

 46:   /*
 47:      Load the matrix; then destroy the viewer.
 48:   */
 49:   MatCreate(PETSC_COMM_WORLD,&A[0]);
 50:   MatLoad(A[0],fd);
 51:   PetscViewerDestroy(&fd);

 53:   MatDuplicate(A[0],MAT_COPY_VALUES,&A[1]);
 54:   MatDuplicate(A[0],MAT_COPY_VALUES,&A[2]);
 55:   MatShift(A[1],1.0);
 56:   MatShift(A[1],2.0);

 58:   MatGetVecs(A[0],&x,&y);
 59:   VecDuplicate(y,&work);
 60:   VecDuplicate(y,&z);

 62:   VecSet(x,1.0);
 63:   MatMult(A[0],x,z);
 64:   MatMultAdd(A[1],x,z,z);
 65:   MatMultAdd(A[2],x,z,z);

 67:   MatCreateComposite(PETSC_COMM_WORLD,3,A,&B);
 68:   MatMult(B,x,y);
 69:   MatDestroy(&B);
 70:   VecAXPY(y,-1.0,z);
 71:   VecNorm(y,NORM_2,&rnorm);
 72:   if (rnorm > 1.e-10) {
 73:     PetscPrintf(PETSC_COMM_WORLD,"Error with composite add %g\n",(double)rnorm);
 74:   }

 76:   MatCreateComposite(PETSC_COMM_WORLD,3,A,&B);
 77:   MatCompositeMerge(B);
 78:   MatMult(B,x,y);
 79:   MatDestroy(&B);
 80:   VecAXPY(y,-1.0,z);
 81:   VecNorm(y,NORM_2,&rnorm);
 82:   if (rnorm > 1.e-10) {
 83:     PetscPrintf(PETSC_COMM_WORLD,"Error with composite add after merge %g\n",(double)rnorm);
 84:   }

 86:   VecSet(x,1.0);
 87:   MatMult(A[0],x,z);
 88:   MatMult(A[1],z,work);
 89:   MatMult(A[2],work,z);

 91:   MatCreateComposite(PETSC_COMM_WORLD,3,A,&B);
 92:   MatCompositeSetType(B,MAT_COMPOSITE_MULTIPLICATIVE);
 93:   MatMult(B,x,y);
 94:   MatDestroy(&B);
 95:   VecAXPY(y,-1.0,z);
 96:   VecNorm(y,NORM_2,&rnorm);
 97:   if (rnorm > 1.e-10) {
 98:     PetscPrintf(PETSC_COMM_WORLD,"Error with composite multiplicative %g\n",(double)rnorm);
 99:   }

101:   MatCreateComposite(PETSC_COMM_WORLD,3,A,&B);
102:   MatCompositeSetType(B,MAT_COMPOSITE_MULTIPLICATIVE);
103:   MatCompositeMerge(B);
104:   MatMult(B,x,y);
105:   MatDestroy(&B);
106:   VecAXPY(y,-1.0,z);
107:   VecNorm(y,NORM_2,&rnorm);
108:   if (rnorm > 1.e-10) {
109:     PetscPrintf(PETSC_COMM_WORLD,"Error with composite multiplicative after merge %g\n",(double)rnorm);
110:   }

112:   /*
113:      Free work space.  All PETSc objects should be destroyed when they
114:      are no longer needed.
115:   */
116:   VecDestroy(&x);
117:   VecDestroy(&y);
118:   VecDestroy(&work);
119:   VecDestroy(&z);
120:   MatDestroy(&A[0]);
121:   MatDestroy(&A[1]);
122:   MatDestroy(&A[2]);

124:   PetscFinalize();
125:   return 0;
126: }