1: #include <petsc/private/dmproductimpl.h>

  3: static PetscErrorCode DMDestroy_Product(DM dm)
  4: {
  5:   DM_Product *product = (DM_Product *)dm->data;

  7:   PetscFunctionBeginUser;
  8:   for (PetscInt d = 0; d < DMPRODUCT_MAX_DIM; ++d) PetscCall(DMDestroy(&product->dm[d]));
  9:   PetscCall(PetscFree(product));
 10:   PetscFunctionReturn(PETSC_SUCCESS);
 11: }

 13: static PetscErrorCode DMView_Product(DM dm, PetscViewer viewer)
 14: {
 15:   DM_Product *product = (DM_Product *)dm->data;

 17:   PetscFunctionBegin;
 18:   for (PetscInt d = 0; d < DMPRODUCT_MAX_DIM; ++d) {
 19:     if (product->dm[d]) {
 20:       PetscCall(PetscViewerASCIIPrintf(viewer, "  DM that defines dimension %" PetscInt_FMT "\n", d));
 21:       PetscCall(PetscViewerASCIIPushTab(viewer));
 22:       PetscCall(PetscViewerASCIIPushTab(viewer));
 23:       PetscCall(DMView(product->dm[d], viewer));
 24:       PetscCall(PetscViewerASCIIPopTab(viewer));
 25:       PetscCall(PetscViewerASCIIPopTab(viewer));
 26:     }
 27:   }
 28:   PetscFunctionReturn(PETSC_SUCCESS);
 29: }

 31: /*MC
 32:   DMPRODUCT = "product" - a `DM` representing a local Cartesian product of other `DM`

 34:   Level: advanced

 36:   Notes:
 37:   The `DM` is usually used for managing coordinates of other `DM` via `DMGetCoordinateDM()` and `DMSetCoordinateDM()`

 39:   For each of `dim` dimensions, the `DMPRODUCT` contains a `DM` and a dimension index. The dimensional index, set with `DMProductSetDimensionIndex()`
 40:   specifies  which dimension of the sub-`DM` coordinates corresponds to a particular dimension of the `DMPRODUCT`. For example,
 41: .vb
 42:   DM da1, da2;
 43:   DM dm
 44:   DMCreate(PETSC_COMM_WORLD,&dm);
 45:   DMSetType(dm,DMPRODUCT);
 46:   DMSetDimension(dm,3);
 47:   DMProductSetDM(dm,0,da1);
 48:   DMProductSetDimensionIndex(dm,0,0);
 49:   DMProductSetDM(dm,1,da2);
 50:   DMProductSetDimensionIndex(dm,1,0);
 51:   DMProductSetDM(dm,2,da1);
 52:   DMProductSetDimensionIndex(dm,2,1);
 53: .ve
 54:   results in a three-dimensional `DM` whose `x` coordinate values are obtained from the `x` coordinate values of `da1`, whose `y` coordinate values are obtained from
 55:   the 'x' coordinate values of `da2` and whose `z` coordinate values are obtained from the `y` coordinate values of `da1`.

 57: .seealso: `DM`, `DMSTAG`, `DMProductGetDM()`, `DMProductSetDimensionIndex()`, `DMProductSetDM()`, `DMStagSetUniformCoordinatesProduct()`,
 58:           `DMStagGetProductCoordinateArrays()`, `DMStagGetProductCoordinateArraysRead()`, `DMGetCoordinateDM()`, `DMSetCoordinateDM()`
 59: M*/

 61: PETSC_EXTERN PetscErrorCode DMCreate_Product(DM dm)
 62: {
 63:   DM_Product *product;

 65:   PetscFunctionBegin;
 66:   PetscAssertPointer(dm, 1);
 67:   PetscCall(PetscNew(&product));
 68:   dm->data = product;

 70:   for (PetscInt d = 0; d < DMPRODUCT_MAX_DIM; ++d) product->dm[d] = NULL;
 71:   for (PetscInt d = 0; d < DMPRODUCT_MAX_DIM; ++d) product->dim[d] = -1;

 73:   dm->ops->destroy = DMDestroy_Product;
 74:   dm->ops->view    = DMView_Product;
 75:   PetscFunctionReturn(PETSC_SUCCESS);
 76: }