# tem_stencilHeader_type Derived Type

## type, public :: tem_stencilHeader_type

Stencil definitions

A stencil is basically a set of element-offsets $(s_x, s_y, s_z)$, describing the relative positions of all required elements for a given element.

## Components

TypeVisibility AttributesNameInitial
character(len=labelLen), public :: label

a stencil label

integer, public :: QQ

number of directions

integer, public :: QQN

number of directions excluding the central (0,0,0)

integer, public :: nDims =0
integer, public, allocatable:: cxDir(:,:)

cartesian directions of discrete velocities. Integer number version. Size is (3,nDir)

real(kind=rk), public, allocatable:: cxDirRK(:,:)

Cartesian directions of discrete velocities. Real number version. Size is (3,nDir)

integer, public, allocatable:: cxDirInv(:)

inverted cartesian direction indices. this is well defined for symmetric stencils only.

real(kind=rk), public, allocatable:: cxcx(:,:)

2nd order tensor of discrete velocities Size is (6,QQ) for 3D: xx, yy, zz, xy, yz, xz (3,QQ) for 2D: xx, yy, xy (1,QQ) for 1D: xx

integer, public, allocatable:: map(:)

mapping of stencil entries to treelm definition, if possible entry is zero if nothing defined,

integer, public, allocatable:: map2treeDef(:)

mapping of treelm definition to stencil entries, if possible entry is zero if nothing defined

integer, public :: restPosition

Rest-density position in stencil

integer, public :: depStencil

the stencil on which the current one depends this is required for boundary stencils which elements actually require the neighbors of the compute stencil

logical, public :: useAll

use this stencil for all elements

logical, public :: requireNeighNeigh =.false.

requires valid neighbors of the stencil neighbors

logical, public :: requireAll =.false.

requires valid neighbors of the stencil neighbors

integer, public :: nElems

the number of elements using this stencil

type(grw_intarray_type), public, allocatable:: elemLvl(:)

list of elements on which this stencil should be applied Both elemLvl and elem array are used for stencil other than fluid stencil

type(grw_intarray_type), public :: elem

list of elements on which this stencil should be applied In build_BCstencil they point to original treeID list and used in tem_initelemLevels. Later this position is updated such that they point to the level wise total list in update_elemPosToTotalPos.

### Source Code

  type tem_stencilHeader_type

!> a stencil label
character(len=labelLen) :: label

!> number of directions
integer :: QQ

!>@todo HK: do we really need this? It is mostly confusing, and solver
!!          specific!
!!
!! number of directions excluding the central (0,0,0)
integer :: QQN
integer :: nDims = 0

!> cartesian directions of discrete velocities.
!! Integer number version.
!! Size is (3,nDir)
integer, allocatable :: cxDir(:,:)

!> Cartesian directions of discrete velocities.
!! Real number version.
!! Size is (3,nDir)
real(kind=rk), allocatable :: cxDirRK(:,:)

!> inverted cartesian direction indices.
!! this is well defined for symmetric stencils only.
integer, allocatable :: cxDirInv(:)

!> 2nd order tensor of discrete velocities
!! Size is (6,QQ) for 3D: xx, yy, zz, xy, yz, xz
!!         (3,QQ) for 2D: xx, yy, xy
!!         (1,QQ) for 1D: xx
real(kind=rk), allocatable :: cxcx(:,:)

!> mapping of stencil entries to treelm definition, if possible
!! entry is zero if nothing defined,
!! @todo: SZ: is this really the case?
!! -1 if a stencil entry with entries further than neighbor are encountered
integer, allocatable :: map(:)

!> mapping of treelm definition to stencil entries, if possible
!! entry is zero if nothing defined
integer, allocatable :: map2treeDef(:)

!> Rest-density position in stencil
integer :: restPosition

!> the stencil on which the current one depends
!! this is required for boundary stencils which elements actually require
!! the neighbors of the compute stencil
integer :: depStencil

!> use this stencil for all elements
logical :: useAll

!> requires valid neighbors of the stencil neighbors
logical :: requireNeighNeigh = .false.

!> requires valid neighbors of the stencil neighbors
logical :: requireAll = .false.

!> the number of elements using this stencil
integer :: nElems

! @todo: SZ: elemLvl and elem host more or less the same data maybe one
!            of them could be removed.
!            - elem is used in tem_construction (not in musubi, as far as
!              I saw)
!            - elemLvl is used in the tem_construction (not in musubi, as
!              far as I saw)

!> list of elements on which this stencil should be applied
!! Both elemLvl and elem array are used for stencil
!! other than fluid stencil
type(grw_intArray_type), allocatable :: elemLvl(:)

!> list of elements on which this stencil should be applied
!! In build_BCstencil they point to original treeID list
!! and used in tem_initelemLevels.
!! Later this position is updated such that they point to
!! the level wise total list in update_elemPosToTotalPos.
! KM: changed from allocatable array to growing array since
! musubi needs to create growing array of stencil headers
! and element list for each stencil header
type(grw_intArray_type) :: elem