Description

This example shows: how to set a key as missing.

Source code

grib_set_missing.f90
! (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 set a key as missing.
!
program set
  use eccodes
  implicit none
  integer              :: infile,outfile
  integer              :: igrib, Ni, is_missing

  infile=5
  outfile=6

  call codes_open_file(infile, &
       '../../data/reduced_gaussian_pressure_level.grib2','r')

  call codes_open_file(outfile, &
       'f_out_surface_level.grib2','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)

  call codes_set(igrib,'typeOfFirstFixedSurface','sfc')
  call codes_set_missing(igrib,'scaleFactorOfFirstFixedSurface')
  call codes_set_missing(igrib,'scaledValueOfFirstFixedSurface')

  ! See GRIB-490
  call codes_get(igrib, 'Ni', Ni)
  call codes_is_missing(igrib,'Ni',is_missing)
  if ( is_missing == 0 ) then
    ! Ni should be missing in gribs with Reduced Gaussian grids
    call codes_check(-2, 'Ni_should_be_missing', '')
  endif
  call codes_set(igrib, 'Ni', Ni)

  call codes_write(igrib,outfile)
  call codes_release(igrib)
  call codes_close_file(infile)
  call codes_close_file(outfile)

end program set
grib_set_missing.py
#
# (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.
#

import traceback
import sys

from eccodes import *

INPUT = '../../data/tigge/tigge_ecmf_pl_t.grib'
OUTPUT = 'out.p_set_missing.grib'
VERBOSE = 1  # verbose error reporting


def example():
    fin = open(INPUT, 'rb')
    fout = open(OUTPUT, 'wb')

    gid = codes_grib_new_from_file(fin)

    codes_set_long(gid, "scaledValueOfFirstFixedSurface", 15)
    codes_set_long(gid, "scaleFactorOfFirstFixedSurface", 1)
    level = codes_get_double(gid, "level")
    assert (level == 1.5)

    # set type of level to surface
    codes_set(gid, 'typeOfFirstFixedSurface', 'sfc')
    codes_set_missing(gid, 'scaleFactorOfFirstFixedSurface')
    codes_set_missing(gid, 'scaledValueOfFirstFixedSurface')

    codes_write(gid, fout)

    codes_release(gid)
    fin.close()
    fout.close()


def main():
    try:
        example()
    except CodesInternalError as err:
        if VERBOSE:
            traceback.print_exc(file=sys.stderr)
        else:
            sys.stderr.write(err.msg + '\n')

        return 1


if __name__ == "__main__":
    sys.exit(main())