Page History

! (C) Copyright 2005-2018 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.
!
!
!  FORTRAN 90 Implementation: grib_clone
!
!  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

#
# (C) Copyright 2005-2018 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
import random

from eccodes import *

INPUT = '../../data/constant_field.grib1'
OUTPUT = 'out.clone.grib'
VERBOSE = 1  # verbose error reporting


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

    gid = codes_grib_new_from_file(fin)

    assert codes_is_missing(gid, 'Ni') == False
    assert codes_is_missing(gid, 'Nj') == False
    nx = codes_get(gid, 'Ni')
    ny = codes_get(gid, 'Nj')

    for step in range(0, 24, 6):
        clone_id = codes_clone(gid)
        codes_set(clone_id, 'step', step)

        values = [random.random() for i in range(nx * ny)]

        codes_set_values(clone_id, values)

        codes_write(clone_id, fout)
        codes_release(clone_id)

    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())

/*
 * (C) Copyright 2005-2018 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.
 */

/*
 * C Implementation: grib_clone
 *
 * Description: How to create a new GRIB message by cloning
 *              an existing message.
 *
 */
#include <stdio.h>
#include "eccodes.h"

static void usage(const char *app)
{
    fprintf(stderr,"Usage is: %s input_file ouput_file\n", app);
}

int main(int argc, char *argv[])
{
    FILE *in = NULL;
    FILE *out = NULL;
    codes_handle *source_handle = NULL;
    const void *buffer = NULL;
    size_t size = 0;
    int err = 0;

    if (argc != 3) {
        usage(argv[0]);
        return 1;
    }

    in = fopen(argv[1],"r");
    out = fopen(argv[2],"w");

    if (!in || !out) {
        perror("ERROR: unable to open files");
        fclose(out);
        fclose(in);
        return 1;
    }

    /* loop over the messages in the source grib and clone them */
    while ((source_handle = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err))!=NULL)
    {
        codes_handle *clone_handle = codes_handle_clone(source_handle);

        if (clone_handle == NULL) {
            perror("ERROR: could not clone field");
            return 1;
        }

        /* This is the place where you may wish to modify the clone */
        /* E.g.
           CODES_CHECK(codes_set_long(clone_handle, "centre", 250),0);
           etc...
         */

        /* get the coded message in a buffer */
        CODES_CHECK(codes_get_message(clone_handle,&buffer,&size),0);
        /* write the buffer to a file */
        if(fwrite(buffer,1,size,out) != size) {
            perror(argv[1]);
            return 1;
        }
        codes_handle_delete(clone_handle);
        codes_handle_delete(source_handle);
    }

    fclose(out);
    fclose(in);

    return 0;
}