eccodes/examples/F90/grib_clone.f90

74 lines
2.4 KiB
Fortran

! (C) Copyright 2005- ECMWF.
!
! This software is licensed under the terms of the Apache Licence Version 2.0
! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
!
! In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
! virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
!
!
! Description: How to create a new GRIB message by cloning
! an existing message.
!
!
program clone
use eccodes
implicit none
integer :: err, i
integer :: nx, ny
integer :: infile, outfile
integer :: igrib_in
integer :: igrib_out
character(len=2) :: step
real(kind=8), dimension(:, :), allocatable :: field2D
call codes_open_file(infile, '../../data/constant_field.grib1', 'r')
call codes_open_file(outfile, 'out.clone.grib1', 'w')
! A new GRIB message is loaded from file.
! igrib is the GRIB id to be used in subsequent calls
call codes_grib_new_from_file(infile, igrib_in)
call codes_get(igrib_in, 'Ni', nx)
call codes_get(igrib_in, 'Nj', ny)
allocate (field2D(nx, ny), stat=err)
if (err .ne. 0) then
print *, 'Failed to allocate ', nx*ny, ' values'
STOP
end if
! clone the constant field to create 4 new GRIB messages
do i = 0, 18, 6
call codes_clone(igrib_in, igrib_out)
write (step, '(i2)') i
! Careful: stepRange is a string (could be 0-6, 12-24, etc.)
! use adjustl to remove blank from the left.
call codes_set(igrib_out, 'stepRange', adjustl(step))
call generate_field(field2D)
! use pack to create 1D values
call codes_set(igrib_out, 'values', pack(field2D, mask=.true.))
! write cloned messages to a file
call codes_write(igrib_out, outfile)
call codes_release(igrib_out)
end do
call codes_release(igrib_in)
call codes_close_file(infile)
call codes_close_file(outfile)
deallocate (field2D)
contains
!======================================
subroutine generate_field(gfield2D)
real(kind=8), dimension(:, :) :: gfield2D
call random_number(gfield2D)
end subroutine generate_field
!======================================
end program clone