Actual source code: ex41.c

petsc-3.13.4 2020-08-01
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  1: static char help[] = "Nest vector set subvector functionality.\n\n";

  3: /*T
  4:    Concepts: vectors^block operators
  5:    Concepts: vectors^setting values
  6:    Concepts: vectors^local access to
  7:    Processors: n
  8: T*/

 10:  #include <petscvec.h>

 12: PetscErrorCode test_vec_ops(void)
 13: {
 14:   Vec            X,Y,a,b;
 15:   Vec            c,d,e,f,g,h;
 16:   PetscScalar    val;
 18:   PetscInt       tmp_ind[2];
 19:   Vec            tmp_buf[2];

 22:   PetscPrintf(PETSC_COMM_WORLD, "============== %s ==============\n",PETSC_FUNCTION_NAME);

 24:   /* create 4 slave vectors */
 25:   VecCreate(PETSC_COMM_WORLD, &c);
 26:   VecSetSizes(c, PETSC_DECIDE, 4);
 27:   VecSetType(c, VECMPI);
 28:   VecDuplicate(c, &d);
 29:   VecDuplicate(c, &e);
 30:   VecDuplicate(c, &f);

 32:   /* create two more slaves of different sizes */
 33:   VecCreate(PETSC_COMM_WORLD, &g);
 34:   VecSetSizes(g, PETSC_DECIDE, 6);
 35:   VecSetType(g, VECMPI);
 36:   VecCreate(PETSC_COMM_WORLD, &h);
 37:   VecSetSizes(h, PETSC_DECIDE, 8);
 38:   VecSetType(h, VECMPI);

 40:   /* set the 6 vectors to some numbers */
 41:   VecSet(c, 1.0);
 42:   VecSet(d, 2.0);
 43:   VecSet(e, 3.0);
 44:   VecSet(f, 4.0);
 45:   VecSet(g, 5.0);
 46:   VecSet(h, 6.0);

 48:   /* assemble a */
 49:   PetscPrintf(PETSC_COMM_WORLD, "a = [c d] \n");
 50:   tmp_buf[0] = c; tmp_buf[1] = d;

 52:   VecCreateNest(PETSC_COMM_WORLD,2,NULL,tmp_buf,&a);
 53:   VecView(a,PETSC_VIEWER_STDOUT_WORLD);
 54:   PetscPrintf(PETSC_COMM_WORLD, "a = [d c] \n");
 55:   VecNestSetSubVec(a, 1, c);
 56:   VecNestSetSubVec(a, 0, d);
 57:   VecAssemblyBegin(a);
 58:   VecAssemblyEnd(a);
 59:   VecView(a,PETSC_VIEWER_STDOUT_WORLD);

 61:   /* assemble b */
 62:   PetscPrintf(PETSC_COMM_WORLD, "b = [e f] \n");
 63:   tmp_buf[0] = e; tmp_buf[1] = f;

 65:   VecCreateNest(PETSC_COMM_WORLD,2,NULL,tmp_buf,&b);
 66:   VecView(b,PETSC_VIEWER_STDOUT_WORLD);
 67:   PetscPrintf(PETSC_COMM_WORLD, "b = [f e] \n");
 68:   VecNestSetSubVec(b, 1, e);
 69:   VecNestSetSubVec(b, 0, f);
 70:   VecAssemblyBegin(b);
 71:   VecAssemblyEnd(b);
 72:   VecView(b,PETSC_VIEWER_STDOUT_WORLD);

 74:   PetscPrintf(PETSC_COMM_WORLD, "X = [a b] \n");
 75:   tmp_buf[0] = a; tmp_buf[1] = b;

 77:   VecCreateNest(PETSC_COMM_WORLD,2,NULL,tmp_buf,&X);
 78:   VecView(X,PETSC_VIEWER_STDOUT_WORLD);
 79:   VecDot(X,X, &val);
 80:   PetscPrintf(PETSC_COMM_WORLD, "X.X = %g \n", (double)PetscRealPart(val));

 82:   PetscPrintf(PETSC_COMM_WORLD, "X = [b a] \n");
 83:   /* re-order components of X */
 84:   VecNestSetSubVec(X,1,a);
 85:   VecNestSetSubVec(X,0,b);
 86:   VecAssemblyBegin(X);
 87:   VecAssemblyEnd(X);
 88:   VecView(X,PETSC_VIEWER_STDOUT_WORLD);
 89:   VecDot(X,X,&val);
 90:   PetscPrintf(PETSC_COMM_WORLD, "X.X = %g \n", (double)PetscRealPart(val));

 92:   /* re-assemble X */
 93:   PetscPrintf(PETSC_COMM_WORLD, "X = [g h] \n");
 94:   VecNestSetSubVec(X,1,g);
 95:   VecNestSetSubVec(X,0,h);
 96:   VecAssemblyBegin(X);
 97:   VecAssemblyEnd(X);
 98:   VecView(X,PETSC_VIEWER_STDOUT_WORLD);
 99:   VecDot(X,X,&val);
100:   PetscPrintf(PETSC_COMM_WORLD, "X.X = %g \n", (double)PetscRealPart(val));

102:   PetscPrintf(PETSC_COMM_WORLD, "Y = X \n");
103:   VecDuplicate(X, &Y);
104:   VecCopy(X,Y);
105:   VecView(Y,PETSC_VIEWER_STDOUT_WORLD);
106:   VecDot(Y,Y,&val);
107:   PetscPrintf(PETSC_COMM_WORLD, "Y.Y = %g \n", (double)PetscRealPart(val));

109:   PetscPrintf(PETSC_COMM_WORLD, "Y = [a b] \n");
110:   tmp_buf[0] = a; tmp_buf[1] = b;
111:   tmp_ind[0] = 0; tmp_ind[1] = 1;

113:   VecNestSetSubVecs(Y,2,tmp_ind,tmp_buf);
114:   VecView(Y,PETSC_VIEWER_STDOUT_WORLD);

116:   VecDestroy(&c);
117:   VecDestroy(&d);
118:   VecDestroy(&e);
119:   VecDestroy(&f);
120:   VecDestroy(&g);
121:   VecDestroy(&h);
122:   VecDestroy(&a);
123:   VecDestroy(&b);
124:   VecDestroy(&X);
125:   VecDestroy(&Y);
126:   return(0);
127: }

129: int main(int argc, char **args)
130: {

133:   PetscInitialize(&argc, &args,(char*)0, help);if (ierr) return ierr;
134:   test_vec_ops();
135:   PetscFinalize();
136:   return ierr;
137: }


140: /*TEST

142:    test:

144: TEST*/