petscimspreconditionermodule Module Reference

Data Types
type	pcshellctxtype
interface	PCShellGetContext

Functions/Subroutines
subroutine	pctx_create (this, matrix, lin_settings)
	Create the preconditioner context from the system matrix. More...
subroutine	pctx_destroy (this)
	Cleanup the context. More...
subroutine, public	pcshell_apply (pc, x, y, ierr)
	Apply shell preconditioner. More...
subroutine, public	pcshell_setup (pc, ierr)
	Set up the custom preconditioner. More...

Variables
character(len=9), dimension(4)	ims_pc_type = ["IMS ILU0 ", "IMS MILU0", "IMS ILUT ", "IMS MILUT"]

Function/Subroutine Documentation

pcshell_apply()

subroutine, public petscimspreconditionermodule::pcshell_apply	(		pc,
			x,
			y,
			ierr
	)

Definition at line 146 of file PetscImsPreconditioner.F90.

    use imslinearbasemodule, only: ims_base_ilu0a
    external lusol ! from ilut.f90
    pc :: pc !< the shell preconditioner
    vec :: x !< the input vector
    vec :: y !< the output vector
    petscerrorcode :: ierr !< PETSc error code
    ! local
    type(PcShellCtxType), pointer :: pc_ctx => null()
    real(DP), dimension(:), pointer :: local_x, local_y
    integer(I4B) :: neq, nja
 
    call pcshellgetcontext(pc, pc_ctx, ierr)
    chkerrq(ierr)
 
    call vecgetarrayreadf90(x, local_x, ierr)
    chkerrq(ierr)
    call vecgetarrayf90(y, local_y, ierr)
    chkerrq(ierr)
 
    neq = pc_ctx%system_matrix%nrow
    nja = pc_ctx%system_matrix%nnz_local
    select case (pc_ctx%ipc)
    case (1, 2)
      call ims_base_ilu0a(nja, neq, pc_ctx%APC, pc_ctx%IAPC, pc_ctx%JAPC, &
                          local_x, local_y)
    case (3, 4)
      call lusol(neq, local_x, local_y, pc_ctx%APC, pc_ctx%JLU, pc_ctx%IW)
    end select
 
    call vecrestorearrayf90(x, local_x, ierr)
    chkerrq(ierr)
    call vecrestorearrayf90(y, local_y, ierr)
    chkerrq(ierr)
 

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pcshell_setup()

subroutine, public petscimspreconditionermodule::pcshell_setup	(		pc,
			ierr
	)

Definition at line 185 of file PetscImsPreconditioner.F90.

    use imslinearbasemodule, only: ims_base_pcu
    pc :: pc !< the shell preconditioner
    petscerrorcode :: ierr !< PETSc error code
    ! local
    type(PcShellCtxType), pointer :: pc_ctx => null()
    integer(I4B) :: neq, nja
    integer(I4B) :: niapc, njapc, njlu, njw, nwlu
    integer(I4B), dimension(:), contiguous, pointer :: ia, ja
    real(DP), dimension(:), contiguous, pointer :: amat
 
    call pcshellgetcontext(pc, pc_ctx, ierr)
    chkerrq(ierr)
 
    ! note the two different matrix types here:
    ! bridging between PETSc and IMS
    call pc_ctx%system_matrix%get_aij_local(ia, ja, amat)
 
    neq = pc_ctx%system_matrix%nrow
    nja = pc_ctx%system_matrix%nnz_local
    niapc = size(pc_ctx%IAPC) - 1
    njapc = size(pc_ctx%JAPC)
    njlu = size(pc_ctx%JLU)
    njw = size(pc_ctx%JW)
    nwlu = size(pc_ctx%WLU)
    call ims_base_pcu(iout, nja, neq, niapc, njapc, &
                      pc_ctx%ipc, pc_ctx%linear_settings%relax, &
                      amat, ia, ja, &
                      pc_ctx%APC, pc_ctx%IAPC, pc_ctx%JAPC, &
                      pc_ctx%IW, pc_ctx%W, &
                      pc_ctx%linear_settings%level, &
                      pc_ctx%linear_settings%droptol, &
                      njlu, njw, nwlu, &
                      pc_ctx%JLU, pc_ctx%JW, pc_ctx%WLU)
 

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pctx_create()

subroutine petscimspreconditionermodule::pctx_create ( class(pcshellctxtype)  this, class(petscmatrixtype), pointer  matrix, type(imslinearsettingstype), pointer  lin_settings  )

private

Parameters

this	this instance
matrix	the linear system matrix
lin_settings	linear settings from IMS

Definition at line 58 of file PetscImsPreconditioner.F90.

    use imslinearbasemodule, only: ims_base_pccrs, ims_calc_pcdims
    use memorymanagermodule, only: mem_allocate
    class(PcShellCtxType) :: this !< this instance
    class(PetscMatrixType), pointer :: matrix !< the linear system matrix
    type(ImsLinearSettingsType), pointer :: lin_settings !< linear settings from IMS
    ! local
    integer(I4B) :: n, neq, nja
    integer(I4B), dimension(:), contiguous, pointer :: ia, ja
    real(DP), dimension(:), contiguous, pointer :: amat
    integer(I4B) :: niapc, njapc, njlu, njw, nwlu
 
    this%memory_path = matrix%memory_path
    this%linear_settings => lin_settings
 
    this%ipc = 1
    if (this%linear_settings%level > 0) this%ipc = this%ipc + 2
    if (this%linear_settings%relax > 0.0_dp) this%ipc = this%ipc + 1
    this%ims_pc_type = ims_pc_type(this%ipc)
 
    this%system_matrix => matrix
    call matrix%get_aij_local(ia, ja, amat)
 
    neq = matrix%nrow
    nja = matrix%nnz_local
    call ims_calc_pcdims(neq, nja, ia, this%linear_settings%level, this%ipc, &
                         niapc, njapc, njlu, njw, nwlu)
 
    ! preconditioner matrix
    call mem_allocate(this%IAPC, niapc + 1, 'IAPC', this%memory_path)
    call mem_allocate(this%JAPC, njapc, 'JAPC', this%memory_path)
    call mem_allocate(this%APC, njapc, 'APC', this%memory_path)
    if (this%ipc == 1 .or. this%ipc == 2) then
      call ims_base_pccrs(niapc, njapc, ia, ja, this%IAPC, this%JAPC)
    end if
    do n = 1, njapc
      this%APC(n) = dzero
    end do
 
    ! (M)ILU0 work arrays
    call mem_allocate(this%IW, niapc, 'IW', this%memory_path)
    call mem_allocate(this%W, niapc, 'W', this%memory_path)
    do n = 1, niapc
      this%IW(n) = izero
      this%W(n) = dzero
    end do
 
    ! (M)ILUT work arrays
    call mem_allocate(this%JLU, njlu, 'JLU', this%memory_path)
    call mem_allocate(this%JW, njw, 'JW', this%memory_path)
    call mem_allocate(this%WLU, nwlu, 'WLU', this%memory_path)
 
    do n = 1, njlu
      this%JLU(n) = izero
    end do
    do n = 1, njw
      this%JW(n) = izero
    end do
    do n = 1, nwlu
      this%WLU(n) = dzero
    end do
 

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pctx_destroy()

subroutine petscimspreconditionermodule::pctx_destroy

(

class(pcshellctxtype)

this

)

Definition at line 124 of file PetscImsPreconditioner.F90.

    use memorymanagermodule, only: mem_deallocate
    class(PcShellCtxType) :: this
 
    ! matrix
    call mem_deallocate(this%IAPC)
    call mem_deallocate(this%JAPC)
    call mem_deallocate(this%APC)
 
    ! work arrays
    call mem_deallocate(this%IW)
    call mem_deallocate(this%W)
    call mem_deallocate(this%JLU)
    call mem_deallocate(this%JW)
    call mem_deallocate(this%WLU)
 
    this%system_matrix => null()
 

Variable Documentation

ims_pc_type

character(len=9), dimension(4) petscimspreconditionermodule::ims_pc_type = ["IMS ILU0 ", "IMS MILU0", "IMS ILUT ", "IMS MILUT"]

private

Definition at line 18 of file PetscImsPreconditioner.F90.

  character(len=9), dimension(4) :: IMS_PC_TYPE = ["IMS ILU0 ", &
                                                   "IMS MILU0", &
                                                   "IMS ILUT ", &
                                                   "IMS MILUT"]