Description
This example shows: how to read data values from a given subset of a BUFR message.
Source code
bufr_subset.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. ! ! ! FORTRAN 90 implementation: bufr_subset ! ! Description: how to read data values from a given subset of a BUFR message. ! ! program bufr_subset use eccodes implicit none integer :: ifile integer :: iret integer :: ibufr integer :: i, count=0 integer(kind=4) :: numberOfSubsets integer(kind=4) :: blockNumber,stationNumber character(100) :: key !real(kind=8) :: t2m call codes_open_file(ifile,'../../data/bufr/synop_multi_subset.bufr','r') ! The first bufr message is loaded from file, ! ibufr is the bufr id to be used in subsequent calls call codes_bufr_new_from_file(ifile,ibufr,iret) do while (iret/=CODES_END_OF_FILE) ! Get and print some keys form the BUFR header write(*,*) 'message: ',count ! We need to instruct ecCodes to expand all the descriptors ! i.e. unpack the data values call codes_set(ibufr,'unpack',1); ! Find out the number of subsets call codes_get(ibufr,'numberOfSubsets',numberOfSubsets) write(*,*) ' numberOfSubsets:',numberOfSubsets ! Loop over the subsets do i=1,numberOfSubsets 100 format('/subsetNumber=',I5.5,'/blockNumber') write(key,100) I write(*,*) key write(*,*) ' subsetNumber:',i ! read and print some data values call codes_get(ibufr,key,blockNumber); write(*,*) ' blockNumber:',blockNumber write(key,*) '/subsetNumber=',I,'/stationNumber' call codes_get(ibufr,'stationNumber',stationNumber); write(*,*) ' stationNumber:',stationNumber end do ! Release the bufr message call codes_release(ibufr) ! Load the next bufr message call codes_bufr_new_from_file(ifile,ibufr,iret) count=count+1 end do ! Close file call codes_close_file(ifile) end program bufr_subset
bufr_subset.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. # # Python implementation: bufr_subset # # Description: how to read data values from a given subset of a BUFR message. # # import sys import traceback from eccodes import * INPUT = '../../data/bufr/synop_multi_subset.bufr' VERBOSE = 1 # verbose error reporting def example(): # open BUFR file f = open(INPUT, 'rb') cnt = 0 # loop for the messages in the file while 1: # get handle for message bufr = codes_bufr_new_from_file(f) if bufr is None: break print("message: %s" % cnt) # we need to instruct ecCodes to expand all the descriptors # i.e. unpack the data values codes_set(bufr, 'unpack', 1) # find out the number of subsets key = 'numberOfSubsets' numberOfSubsets = codes_get(bufr, 'numberOfSubsets') print(' %s: %d' % (key, numberOfSubsets)) # loop over the subsets for i in range(1, numberOfSubsets + 1): # read and print some data values key = '/subsetNumber=%d/blockNumber' % i print(key) val = codes_get_long(bufr, key) print(' %s= %d' % (key, val)) key = '/subsetNumber=%d/stationNumber' % i val = codes_get_long(bufr, key) print(' %s: %d' % (key, val)) cnt += 1 # delete handle codes_release(bufr) # close the file f.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())
bufr_subset.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. */ /* * C Implementation: bufr_subset * * Description: how to read data values from a given subset of a BUFR message. * */ #include "eccodes.h" int main(int argc,char* argv[]) { char key[200]={0,}; FILE* in = NULL; /* message handle. Required in all the eccodes calls acting on a message.*/ codes_handle* h=NULL; long numberOfSubsets=0; long longVal; double doubleVal; size_t stringLen; char stringVal[100]={0,}; int i,err=0; int cnt=0; const char* infile = "../../data/bufr/synop_multi_subset.bufr"; in=fopen(infile,"rb"); if (!in) { printf("ERROR: unable to open file %s\n", infile); return 1; } /* loop over the messages in the bufr file */ while ((h = codes_handle_new_from_file(NULL,in,PRODUCT_BUFR,&err)) != NULL || err != CODES_SUCCESS) { if (h == NULL) { printf("Error: unable to create handle for message %d\n",cnt); cnt++; continue; } printf("message: %d\n",cnt); /* we need to instruct ecCodes to expand all the descriptors i.e. unpack the data values */ CODES_CHECK(codes_set_long(h,"unpack",1),0); /* find out the number of subsets */ CODES_CHECK(codes_get_long(h,"numberOfSubsets",&numberOfSubsets),0); printf(" numberOfSubsets: %ld\n",numberOfSubsets); /* loop over the subsets */ for(i=1; i <= numberOfSubsets; i++) { sprintf(key,"/subsetNumber=%d/blockNumber",i); printf(" subsetNumber=%d",i); /* read and print some data values */ CODES_CHECK(codes_get_long(h,key,&longVal),0); printf(" blockNumber=%ld",longVal); sprintf(key,"/subsetNumber=%d/stationNumber",i); CODES_CHECK(codes_get_long(h,key,&longVal),0); printf(" stationNumber=%ld",longVal); sprintf(key,"/subsetNumber=%d/stationOrSiteName",i); stringLen=100; CODES_CHECK(codes_get_string(h,key,stringVal,&stringLen),0); printf(" stationOrSiteName=\"%s\"",stringVal); sprintf(key,"/subsetNumber=%d/airTemperature",i); CODES_CHECK(codes_get_double(h,key,&doubleVal),0); printf(" airTemperature=%g\n",doubleVal); } /* delete handle */ codes_handle_delete(h); cnt++; } fclose(in); return 0; }