#include <source/transfer/datamovers/locally_active/LocallyActiveDataCoarsenAlgorithm.h>
Note that this algorithm class is similar to the CoarsenAlgorithm<DIM> class. However, unlike the standard coarsen algorithm class, this one does not support resetting communication schedules.
Communication algorithms generally consist of three parts: an algorithm, a schedule, and a patch strategy. The algorithm describes the communication between patch data items but is independent of the configuration of the AMR hierarchy. Patch data items and their associated coarsening operators are registered with the algorithm. To generate the communication dependencies for a particular hierarchy configuration, the algorithm generates a schedule based on the current hierarchy configuration. This schedule then performs the communication based on the registered data types and their associated operators. User-defined pre-processing and post-processing and provided through the abstract patch strategy class.
The source patch data space is used during processing to store temporary data. Thus, the user-defined coarsening operators should operate on the source space by using the patch data with those indices.
Note that each coarsen schedule created by a coarsen algorithm remains valid as long as the patches involved in the communication process do not change; thus, they can be used for multiple data communication cycles.
Typical usage of a coarsen algorithm to perform data coarsening on an AMR hierarchy involves four steps:
| SAMRAI::xfer::LocallyActiveDataCoarsenAlgorithm< DIM >::LocallyActiveDataCoarsenAlgorithm | ( | bool | fill_coarse_data = false |
) |
Construct a coarsening algorithm and initialize its basic state. Coarsening operations must be registered with this algorithm before it can do anything useful. See the registerCoarsen() routine for details
| fill_coarse_data | boolean flag indicating whether coarse level data is needed for the data coarsening operations. By default this argument is false. If a true value is provided, then source data will be filled on a temporary coarse patch level (i.e., copied from the actual coarse level source data) for use in coarsening operations registered with this algorithm. This option should only be used by those who specifically require this behavior and who know how to properly process the patch data on coarse and fine patch levels during the coarsening process. |
| SAMRAI::xfer::LocallyActiveDataCoarsenAlgorithm< DIM >::~LocallyActiveDataCoarsenAlgorithm | ( | ) | [virtual] |
The virtual destructor for the algorithm releases all internal storage.
| void SAMRAI::xfer::LocallyActiveDataCoarsenAlgorithm< DIM >::registerCoarsen | ( | const int | dst, | |
| const int | src, | |||
| const tbox::Pointer< xfer::CoarsenOperator< DIM > > | opcoarsen, | |||
| const hier::IntVector< DIM > & | gcw_to_coarsen = hier::IntVector< DIM >(0) | |||
| ) |
Register a coarsening operation with the coarsening algorithm. Data from the interiors of the source component on a source (fine) patch level will be coarsened into the source component of a temporary (coarse) patch level and then copied into the destination component on the destination (coarse) patch level. If the coarsening operator requires data in ghost cells outside of the patch interiors (i.e., a non-zero stencil width), then those ghost cells must exist in the source patch data component and the ghost cells must be filled with valid data on the source level before a call to invoke the communication schedule. Note that the source and destination components may be the same in any case.
Some special circumstances require that data be coarsened from the ghost cell regions of a finer level and the resulting coarsened data should be copied to the destination patch level. When this is the case, the optional integer vector argument should be set to the cell width, in the destination (coarser) level index space, of the region around the fine level where this coarsening should occur. For example, if the coarser level needs data in a region two (coarse) cells wide around the boundary of the finer level, then the gcw_to_coarsen should be set to a vector with all entries set to two. Moreover, if the refinement ratio between coarse and fine levels is four in this case, then the source patch data is required to have at least eight ghost cells.
| dst | Patch data index filled on destination level. | |
| src | Patch data index coarsened from the source level. | |
| opcoarsen | Pointer to coarsening operator. This may be a null pointer. In this case, coarsening must be handled by the coarsen patch strategy member functions. See the comments for preprocessCoarsen() and postprocessCoarsen() functions in the LocallyActiveDataCoarsenPatchStrategy<DIM> class. | |
| gcw_to_coarsen | Integer vector ghost cell width when data should be coarsened from ghost cell regions of the source (finer) level into the destination (coarser) level. By default, it is the vector of zeros indicating that data should be coarsened from from patch interiors on the source level. If this argument is used, its value should be the cell width, in the destination (coarser) level index space, of the region around the fine level where this coarsening should occur. This argument should only be provided by those who specifically require this special behavior and know how to properly process the patch data on coarse and fine patch levels during the coarsening process. |
| tbox::Pointer< xfer::LocallyActiveDataCoarsenSchedule< DIM > > SAMRAI::xfer::LocallyActiveDataCoarsenAlgorithm< DIM >::createSchedule | ( | tbox::Pointer< hier::PatchLevel< DIM > > | crse_level, | |
| tbox::Pointer< hier::LocallyActiveDataPatchLevelManager< DIM > > | crse_level_mgr, | |||
| tbox::Pointer< hier::PatchLevel< DIM > > | fine_level, | |||
| tbox::Pointer< hier::LocallyActiveDataPatchLevelManager< DIM > > | fine_level_mgr, | |||
| xfer::LocallyActiveDataCoarsenPatchStrategy< DIM > * | patch_strategy = ((xfer::LocallyActiveDataCoarsenPatchStrategy< DIM > *)(0)), |
|||
| tbox::Pointer< xfer::LocallyActiveDataCoarsenTransactionFactory< DIM > > | transaction_factory = (xfer::LocallyActiveDataCoarsenTransactionFactory< DIM > *)(0) | |||
| ) |
Create a communication schedule to coarsen data from the patch levels. This communication schedule may then be executed to perform the data transfers. This schedule creation procedure assumes that the coarse level represents a ragion of coarser index space than the fine level. To avoid potentially erroneous behavior, the coarse level domain should cover the domain of the fine level.
Neither patch level can be null and when assertion checking is active, passing a null level pointer will produce an unrecoverable exception.
Note that the schedule remains valid as long as the patches on the levels do not change; thus, it can be used for multiple data communication cycles.
| crse_level | Pointer to coarse (destination) level; cannot be null. | |
| crse_level_mgr | Pointer to coarse level data manager; cannot be null. | |
| fine_level | Pointer to fine (source) level; cannot be null. | |
| fine_level_mgr | Pointer to fine level data manager; cannot be null. | |
| patch_strategy | Pointer to a coarsen patch strategy that provides user-defined coarsen operations. If this patch strategy is null (default state), then no user-defined coarsen operations will be performed. | |
| transaction_factory | Optional tbox::Pointer to a coarsen transaction factory that creates data transactions for the schedule. If this pointer is null (default state), then a StandardLocallyActiveDataCoarsenTransactionFactory object will be used. |
| void SAMRAI::xfer::LocallyActiveDataCoarsenAlgorithm< DIM >::printClassData | ( | std::ostream & | stream | ) | const [virtual] |
Print the coarsen algorithm state to the specified data stream.
| stream | Output data stream. |
1.5.1