NAME
Grid_getBlkNeighLevels
SYNOPSIS
call Grid_getBlkNeighLevels(integer(IN) :: blockID,
integer(OUT) :: levels(-1:1,-K2D:K2D,-K3D:K3D) )
DESCRIPTION
For a given block, return refinement level information for its neigboring blocks in all directions, including diagonal. It is assumed that blockID indicates a leaf block. The level information returned can be used to determine the leaf block resolution from which data in the various guard cell regions of block blockID is derived when Grid_fillGuardCells is called. In particular, the caller can determine from this info for each guard cell region whether the guard cell data has been derived from interpolation or averaging, or by copying of unmodified leaf block data only.
ARGUMENTS
blockID : ID of block in current processor
levels : returns refinement level for the neigboring regions if
the information is easily available on the executing MPI task,
or one of the following indicators:
* 1 .. lrefine_max a refinement level
* -2 unknown or mixed refinement level
<= lrefine(blockID)
* -3 unknown or mixed refinement level
* 10002 unknown or mixed refinement level
>= lrefine(blockID)
* 10003 unknown or mixed refinement level
> lrefine(blockID)
* 0 no information available
The argument levels is an integer array of shape (3,1,1) for
NDIM=1, (3,3,1) for NDIM=2, or (3,3,3) for NDIM=3.
If its bounds are declared as dimension(-1:1,-K2D:K2D,-K3D:K3D),
then
* levels(0,0,0) always refers to the inner cells of block blockID
itself and will always be set to the refinement level of blockID.
The functionality of Grid_getBlkNeighLevels thus includes that
of Grid_getBlkRefineLevel in all implementations.
* levels(-1,0,0) and (+1,0,0) refer to left (West) and right (East)
neighbors in the I direction, respectively.
* levels(0,-1,0) and (0,+1,0) refer to lower (South) and upper (North)
neighbors in the J direction, respectively.
* levels(0,0,-1) and (0,0,+1) refer to below and above
neighbors in the K direction, respectively.
* other elements refer to neighbors in diagonal directions.
NOTES
With a PARAMESH 4 Grid implementation, refinement level information
is taken from the PARAMESH private array surr_blks and is always
available for all directions.
With the PARAMESH 2 Grid implementation, refinement level information
is taken from the PARAMESH private array neigh and is currently only
available for face directions, not diagonal directions.
With a uniform Grid implementation, refinement level 1 is returned
for all directions since all blocks are considered to be at refinement
level 1.
With the Chombo AMR Grid, this interface is not yet implemented as of FLASH 4.2.
The actual argument corresponding to the level dummy argument may be
declared in the caller in various ways, for example
integer :: levels(-1:1, -K2D:K2D , -K3D:K3D)
or
integer :: levels(3 , 1:1+2*K2D, 1:1+2*K3D)
can be used equivalently (independent of whether NDIM = 1,2, or 3).
NDIM,K2D,K3D are defined in Flash.h or constants.h.
SEE ALSO
Grid_getBlkRefineLevel gr_findAllNeghID