horiz_interp_bicubic.F90

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!> @defgroup horiz_interp_bicubic_mod horiz_interp_bicubic_mod
!> @ingroup horiz_interp
!> @brief Delivers methods for bicubic interpolation from a coarse regular grid
!! on a fine regular grid
!!
!> This module delivers methods for bicubic interpolation from a
!! coarse regular grid on a fine regular grid.
!! Subroutines
!!
!! - @ref bcuint
!! - @ref bcucof
!!
!! are methods taken from
!!
!!       W. H. Press, S. A. Teukolski, W. T. Vetterling and B. P. Flannery,
!!       Numerical Recipies in FORTRAN, The Art of Scientific Computing.
!!       Cambridge University Press, 1992
!!
!! written by
!!       martin.schmidt@io-warnemuende.de (2004)
!! revised by
!!       martin.schmidt@io-warnemuende.de (2004)
!!
!! Version 1.0.0.2005-07-06
!! The module is thought to interact with MOM-4.
!! Alle benotigten Felder werden extern von MOM verwaltet, da sie
!! nicht fur alle interpolierten Daten die gleiche Dimension haben mussen.
module horiz_interp_bicubic_mod
 
  use mpp_mod,               only: mpp_error, fatal, stdout, mpp_pe, mpp_root_pe
  use fms_mod,               only: write_version_number
  use horiz_interp_type_mod, only: horiz_interp_type, bicubic
  use constants_mod,         only: pi
  use platform_mod,          only: r4_kind, r8_kind
 
 
 implicit none
 
   private
 
   public  :: horiz_interp_bicubic, horiz_interp_bicubic_new, horiz_interp_bicubic_del, fill_xy
   public  :: horiz_interp_bicubic_init
 
  !> Creates a new @ref horiz_interp_type for bicubic interpolation.
  !! Allocates space and initializes a derived-type variable
  !! that contains pre-computed interpolation indices and weights.
  !> @ingroup horiz_interp_bicubic_mod
  interface horiz_interp_bicubic_new
    module procedure horiz_interp_bicubic_new_1d_r8
    module procedure horiz_interp_bicubic_new_1d_s_r8
    module procedure horiz_interp_bicubic_new_1d_r4
    module procedure horiz_interp_bicubic_new_1d_s_r4
  end interface
 
  !> @brief Perform bicubic horizontal interpolation
  interface horiz_interp_bicubic
    module procedure horiz_interp_bicubic_r4
    module procedure horiz_interp_bicubic_r8
  end interface
 
!> @addtogroup horiz_interp_bicubic_mod
!> @{
 
! Include variable "version" to be written to log file.
#include<file_version.h>
   logical            :: module_is_initialized = .false.
   integer            :: verbose_bicubic = 0
 
!     Grid variables
!     xc, yc : co-ordinates of the coarse grid
!     xf, yf : co-ordinates of the fine grid
!     fc     : variable to be interpolated at the coarse grid
!     dfc_x  : x-derivative of fc at the coarse grid
!     dfc_y  : y-derivative of fc at the coarse grid
!     dfc_xy : x-y-derivative of fc at the coarse grid
!     ff     : variable to be interpolated at the fine grid
!     dff_x  : x-derivative of fc at the fine grid
!     dff_y  : y-derivative of fc at the fine grid
!     dff_xy : x-y-derivative of fc at the fine grid
 
 
   real(r8_kind)               :: tpi
 
   !! Private interfaces for mixed precision helper routines
 
   interface fill_xy
      module procedure fill_xy_r4
      module procedure fill_xy_r8
   end interface
 
   interface bcuint
      module procedure bcuint_r4
      module procedure bcuint_r8
   end interface
 
   interface bcucof
      module procedure bcucof_r4
      module procedure bcucof_r8
   end interface
 
   !> find the lower neighbour of xf in field xc, return is the index
   interface indl
      module procedure indl_r4
      module procedure indl_r8
   end interface
 
   !> find the upper neighbour of xf in field xc, return is the index
   interface indu
      module procedure indu_r4
      module procedure indu_r8
   end interface
 
   contains
 
  !> @brief Initializes module and writes version number to logfile.out
  subroutine horiz_interp_bicubic_init
 
     if(module_is_initialized) return
     call write_version_number("HORIZ_INTERP_BICUBIC_MOD", version)
     module_is_initialized = .true.
     tpi = real(2.0_r8_kind*pi, r8_kind)
 
  end subroutine horiz_interp_bicubic_init
 
  !> Free memory from a horiz_interp_type used for bicubic interpolation
  !! (allocated via @ref horiz_bicubic_new)
  subroutine horiz_interp_bicubic_del( Interp )
    type(horiz_interp_type), intent(inout) :: interp
 
    if(interp%horizInterpReals8_type%is_allocated) then
      if(allocated(interp%horizInterpReals8_type%rat_x))  deallocate ( interp%horizInterpReals8_type%rat_x )
      if(allocated(interp%horizInterpReals8_type%rat_y))  deallocate ( interp%horizInterpReals8_type%rat_y )
      if(allocated(interp%horizInterpReals8_type%lon_in)) deallocate ( interp%horizInterpReals8_type%lon_in )
      if(allocated(interp%horizInterpReals8_type%lat_in)) deallocate ( interp%horizInterpReals8_type%lat_in )
      if(allocated(interp%horizInterpReals8_type%wti))    deallocate ( interp%horizInterpReals8_type%wti )
    else if(interp%horizInterpReals4_type%is_allocated) then
      if(allocated(interp%horizInterpReals4_type%rat_x))  deallocate ( interp%horizInterpReals4_type%rat_x )
      if(allocated(interp%horizInterpReals4_type%rat_y))  deallocate ( interp%horizInterpReals4_type%rat_y )
      if(allocated(interp%horizInterpReals4_type%lon_in)) deallocate ( interp%horizInterpReals4_type%lon_in )
      if(allocated(interp%horizInterpReals4_type%lat_in)) deallocate ( interp%horizInterpReals4_type%lat_in )
      if(allocated(interp%horizInterpReals4_type%wti))    deallocate ( interp%horizInterpReals4_type%wti )
    endif
    if( allocated(interp%i_lon) ) deallocate( interp%i_lon )
    if( allocated(interp%j_lat) ) deallocate( interp%j_lat )
 
    interp%horizInterpReals8_type%is_allocated = .false.
    interp%horizInterpReals4_type%is_allocated = .false.
 
  end subroutine horiz_interp_bicubic_del
 
#include "horiz_interp_bicubic_r4.fh"
#include "horiz_interp_bicubic_r8.fh"
 
end module horiz_interp_bicubic_mod
!> @}
! close documentation