Description
This example shows: how to set key values in GRIB messages
Source code
grib_set_keys.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 key values in GRIB messages ! ! program set use eccodes implicit none integer(kind = 4) :: centre, date1 integer :: infile,outfile integer :: igrib character(len=12) :: marsType = 'ses' centre = 80 call current_date(date1) call codes_open_file(infile, '../../data/regular_latlon_surface_constant.grib1','r') call codes_open_file(outfile, 'out.set.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) call codes_set(igrib,'dataDate',date1) call codes_set(igrib,'type', marsType) ! set centre as a integer */ call codes_set(igrib,'centre',centre) ! Check if it is correct in the actual GRIB message call check_settings(igrib) ! Write modified message to a file call codes_write(igrib,outfile) call codes_release(igrib) call codes_close_file(infile) call codes_close_file(outfile) contains !====================================== subroutine current_date(date1) integer, intent(out) :: date1 integer :: val_date(8) call date_and_time ( values = val_date) date1 = val_date(1)* 10000 + val_date(2)*100 + val_date(3) end subroutine current_date !====================================== subroutine check_settings(gribid) implicit none integer, intent(in) :: gribid integer(kind = 4) :: int_value character(len = 10) :: string_value ! get centre as a integer call codes_get(gribid,'centre',int_value) write(*,*) "get centre as a integer - centre = ",int_value ! get centre as a string call codes_get(gribid,'centre',string_value) write(*,*) "get centre as a string - centre = ",string_value ! get date as a string call codes_get(gribid,'dataDate',string_value) write(*,*) "get date as a string - date = ",string_value end subroutine check_settings end program set
grib_set_keys.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. # # Description: how to set key values in GRIB messages # import traceback import sys from eccodes import * from datetime import date from collections import OrderedDict INPUT = '../../data/regular_latlon_surface_constant.grib1' OUTPUT = 'out.set.grib' VERBOSE = 1 # verbose error reporting def example(): fin = open(INPUT, 'rb') fout = open(OUTPUT, 'wb') gid = codes_grib_new_from_file(fin) dt = date.today() today = "%d%02d%02d" % (dt.year, dt.month, dt.day) codes_set(gid, 'dataDate', int(today)) codes_set(gid, 'centre', 80) centreIntVal = codes_get_array(gid, 'centre', int) centreStrVal = codes_get_array(gid, 'centre', str) dateStrVal = codes_get_array(gid, 'dataDate', str) assert (centreIntVal[0] == 80) assert (centreStrVal[0] == 'cnmc') assert (dateStrVal[0] == today) print('get centre as an integer - centre = %d' % centreIntVal[0]) print('get centre as a string - centre = %s' % centreStrVal[0]) print('get date as a string - date = %s' % dateStrVal[0]) # Now do the same but using set_key_vals, setting keys all at once print('set keys using one long comma-separated string...') codes_set_key_vals(gid, 'level=1,centre=98') assert (codes_get(gid, 'centre', str) == 'ecmf') assert (codes_get(gid, 'level', int) == 1) print('set keys using a list of strings...') codes_set_key_vals(gid, ['level=2', 'centre=kwbc']) assert (codes_get(gid, 'centre', int) == 7) assert (codes_get(gid, 'level', int) == 2) print('set keys using a dictionary (order not as specified!)...') codes_set_key_vals(gid, {'level': 3, 'centre': 84}) assert (codes_get(gid, 'centre', str) == 'lfpw') assert (codes_get(gid, 'level', int) == 3) print('set keys using an ordered dictionary...') codes_set_key_vals(gid, OrderedDict([('level', 3), ('centre', 84)])) assert (codes_get(gid, 'centre', str) == 'lfpw') assert (codes_get(gid, 'level', int) == 3) codes_gts_header(True) codes_gts_header(False) 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())
grib_set_keys.c
/* * (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 key values in GRIB messages * */ #include <stdio.h> #include <stdlib.h> #include "eccodes.h" int main(int argc, char** argv) { int err = 0; long centre=80; long long_value=0; char string_value[100]; size_t len = sizeof(string_value)/sizeof(char); size_t size=0; FILE* in = NULL; const char* infile = "../../data/regular_latlon_surface.grib1"; FILE* out = NULL; const char* outfile = "out.set.grib1"; codes_handle *h = NULL; const void* buffer = NULL; size_t str_len = 0; /* See the call to codes_set_string later */ in = fopen(infile,"r"); if(!in) { printf("ERROR: unable to open file %s\n",infile); return 1; } out = fopen(outfile,"w"); if(!out) { printf("ERROR: unable to open file %s\n",outfile); fclose(in); return 1; } /* create a new handle from a message in a file */ h = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err); if (h == NULL) { printf("Error: unable to create handle from file %s\n",infile); } /* set centre as a long */ CODES_CHECK(codes_set_long(h,"centre",centre),0); /* set paramId and shortName - normally you would do one or the other */ CODES_CHECK(codes_set_long(h,"paramId", 500004),0); /* the value of str_len is not used, it can be anything! */ CODES_CHECK(codes_set_string(h,"shortName", "fis", &str_len),0); /* get centre as a long */ CODES_CHECK(codes_get_long(h,"centre",&long_value),0); printf("centre long value=%ld\n",long_value); /* get centre as a string */ CODES_CHECK(codes_get_string(h,"centre",string_value,&len),0); printf("centre string value=%s\n",string_value); /* get the coded message in a buffer */ CODES_CHECK(codes_get_message(h,&buffer,&size),0); /* write the buffer in a file*/ if(fwrite(buffer,1,size,out) != size) { perror(argv[1]); exit(1); } codes_handle_delete(h); fclose(in); fclose(out); return 0; }