xref: /petsc/src/dm/impls/da/dadist.c (revision bfcb38ea38335faa6e7f8d97f6bc6ce9aa2a1dd1)
1 
2 /*
3   Code for manipulating distributed regular arrays in parallel.
4 */
5 
6 #include <petsc/private/dmdaimpl.h>    /*I   "petscdmda.h"   I*/
7 
8 PetscErrorCode  VecDuplicate_MPI_DA(Vec g,Vec *gg)
9 {
10   PetscErrorCode ierr;
11   DM             da;
12   PetscLayout    map;
13 
14   PetscFunctionBegin;
15   ierr = VecGetDM(g, &da);CHKERRQ(ierr);
16   ierr = DMCreateGlobalVector(da,gg);CHKERRQ(ierr);
17   ierr = VecGetLayout(g,&map);CHKERRQ(ierr);
18   ierr = VecSetLayout(*gg,map);CHKERRQ(ierr);
19   PetscFunctionReturn(0);
20 }
21 
22 
23 PetscErrorCode  DMCreateGlobalVector_DA(DM da,Vec *g)
24 {
25   PetscErrorCode ierr;
26   DM_DA          *dd = (DM_DA*)da->data;
27 
28   PetscFunctionBegin;
29   PetscValidHeaderSpecific(da,DM_CLASSID,1);
30   PetscValidPointer(g,2);
31   if (da->defaultSection) {
32     ierr = DMCreateGlobalVector_Section_Private(da,g);CHKERRQ(ierr);
33     /* The view and load functions break for general layouts */
34     PetscFunctionReturn(0);
35   } else {
36     ierr = VecCreate(PetscObjectComm((PetscObject)da),g);CHKERRQ(ierr);
37     ierr = VecSetSizes(*g,dd->Nlocal,PETSC_DETERMINE);CHKERRQ(ierr);
38     ierr = VecSetBlockSize(*g,dd->w);CHKERRQ(ierr);
39     ierr = VecSetType(*g,da->vectype);CHKERRQ(ierr);
40     ierr = VecSetDM(*g, da);CHKERRQ(ierr);
41     ierr = VecSetLocalToGlobalMapping(*g,da->ltogmap);CHKERRQ(ierr);
42   }
43   ierr = VecSetOperation(*g,VECOP_VIEW,(void (*)(void))VecView_MPI_DA);CHKERRQ(ierr);
44   ierr = VecSetOperation(*g,VECOP_LOAD,(void (*)(void))VecLoad_Default_DA);CHKERRQ(ierr);
45   ierr = VecSetOperation(*g,VECOP_DUPLICATE,(void (*)(void))VecDuplicate_MPI_DA);CHKERRQ(ierr);
46   PetscFunctionReturn(0);
47 }
48 
49 /*@
50    DMDACreateNaturalVector - Creates a parallel PETSc vector that
51    will hold vector values in the natural numbering, rather than in
52    the PETSc parallel numbering associated with the DMDA.
53 
54    Collective
55 
56    Input Parameter:
57 .  da - the distributed array
58 
59    Output Parameter:
60 .  g - the distributed global vector
61 
62    Level: developer
63 
64    Note:
65    The output parameter, g, is a regular PETSc vector that should be destroyed
66    with a call to VecDestroy() when usage is finished.
67 
68    The number of local entries in the vector on each process is the same
69    as in a vector created with DMCreateGlobalVector().
70 
71 .seealso: DMCreateLocalVector(), VecDuplicate(), VecDuplicateVecs(),
72           DMDACreate1d(), DMDACreate2d(), DMDACreate3d(), DMGlobalToLocalBegin(),
73           DMGlobalToLocalEnd(), DMDALocalToGlobalBegin()
74 @*/
75 PetscErrorCode  DMDACreateNaturalVector(DM da,Vec *g)
76 {
77   PetscErrorCode ierr;
78   PetscInt       cnt;
79   DM_DA          *dd = (DM_DA*)da->data;
80 
81   PetscFunctionBegin;
82   PetscValidHeaderSpecificType(da,DM_CLASSID,1,DMDA);
83   PetscValidPointer(g,2);
84   if (dd->natural) {
85     ierr = PetscObjectGetReference((PetscObject)dd->natural,&cnt);CHKERRQ(ierr);
86     if (cnt == 1) { /* object is not currently used by anyone */
87       ierr = PetscObjectReference((PetscObject)dd->natural);CHKERRQ(ierr);
88       *g   = dd->natural;
89     } else {
90       ierr = VecDuplicate(dd->natural,g);CHKERRQ(ierr);
91     }
92   } else { /* create the first version of this guy */
93     ierr = VecCreate(PetscObjectComm((PetscObject)da),g);CHKERRQ(ierr);
94     ierr = VecSetSizes(*g,dd->Nlocal,PETSC_DETERMINE);CHKERRQ(ierr);
95     ierr = VecSetBlockSize(*g, dd->w);CHKERRQ(ierr);
96     ierr = VecSetType(*g,da->vectype);CHKERRQ(ierr);
97     ierr = PetscObjectReference((PetscObject)*g);CHKERRQ(ierr);
98 
99     dd->natural = *g;
100   }
101   PetscFunctionReturn(0);
102 }
103 
104 
105 
106