! (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 bitmap in a GRIB message
! to encode missing values in the data
!
!
program set_bitmap
use eccodes
implicit none
integer :: infile,outfile
integer :: igrib, iret
integer :: numberOfValues
real, dimension(:), allocatable :: values
real :: missingValue
logical :: grib1Example
grib1Example=.true.
if (grib1Example) then
! GRIB 1 example
call codes_open_file(infile,'../../data/regular_latlon_surface.grib1','r')
else
! GRIB 2 example
call codes_open_file(infile,'../../data/regular_latlon_surface.grib2','r')
end if
call codes_open_file(outfile,'out.set_bitmap_f.grib','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)
! The missingValue is not coded in the message.
! It is a value we define as a placeholder for a missing value
! at a point in the grid.
! It should be chosen so that it cannot be confused
! with a valid field value
missingValue=1.0e36
call codes_set(igrib, 'missingValue',missingValue)
write(*,*) 'missingValue=',missingValue
! get the size of the values array
call codes_get_size(igrib,'values',numberOfValues)
write(*,*) 'numberOfValues=',numberOfValues
allocate(values(numberOfValues), stat=iret)
! get data values
call codes_get(igrib,'values',values)
! enable bitmap
call codes_set(igrib, 'bitmapPresent', 1)
! set some values to be missing
values(1:10) = missingValue
! set the values (the bitmap will be automatically built)
call codes_set(igrib,'values', values)
! write modified message to a file
call codes_write(igrib,outfile)
! free memory
call codes_release(igrib)
call codes_close_file(infile)
call codes_close_file(outfile)
deallocate(values)
end program set_bitmap
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# (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 bitmap in a GRIB message
# to encode missing values in the data
#
import traceback
import sys
from eccodes import *
INPUT = '../../data/regular_latlon_surface.grib1'
OUTPUT = 'out.set_bitmap_p.grib'
MISSING = 1.0e36
VERBOSE = 1 # verbose error reporting
def example():
fin = open(INPUT, 'rb')
fout = open(OUTPUT, 'wb')
gid = codes_grib_new_from_file(fin)
# The missingValue is not coded in the message.
# It is a value we define as a placeholder for a missing value
# at a point in the grid.
# It should be chosen so that it cannot be confused
# with a valid field value
codes_set(gid, 'missingValue', MISSING)
values = codes_get_values(gid)
# Enable bitmap
codes_set(gid, 'bitmapPresent', 1)
# Change some data values to be missing
num_missing = 0
for i in range(100):
# Set every other value to a missing value
if i % 2 == 0:
values[i] = MISSING
num_missing += 1
codes_set_values(gid, values)
# Check counts of missing and non-missing values
num_data = codes_get(gid, 'numberOfDataPoints', int)
assert num_data == len(values)
assert codes_get(gid, 'numberOfCodedValues', int) == num_data - num_missing
assert codes_get(gid, 'numberOfMissing', int) == num_missing
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:
print(err.msg, file=sys.stderr)
return 1
if __name__ == "__main__":
sys.exit(main())
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/*
* (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: grib_set_bitmap
*
* Description: how to set a bitmap in a GRIB message
* to encode missing values in the data
*
*/
#include <stdio.h>
#include <stdlib.h>
#include "eccodes.h"
int main(int argc, char** argv)
{
int err = 0;
size_t size=0;
FILE* in = NULL;
const char* infile = "../../data/regular_latlon_surface.grib1";
FILE* out = NULL;
const char* outfile = "out.set_bitmap_c.grib";
codes_handle *h = NULL;
const void* buffer = NULL;
size_t values_len;
double* values;
double missing=1.0e36;
int i=0;
in = fopen(infile, "r");
if(!in) {
printf("ERROR: unable to open input file %s\n",infile);
return 1;
}
out = fopen(outfile, "w");
if(!out) {
printf("ERROR: unable to open output file %s\n",outfile);
fclose(in);
return 1;
}
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);
}
CODES_CHECK(codes_set_double(h, "missingValue", missing),0);
/* get the size of the values array*/
CODES_CHECK(codes_get_size(h, "values", &values_len),0);
values = (double*)malloc(values_len*sizeof(double));
/* get data values*/
CODES_CHECK(codes_get_double_array(h, "values", values, &values_len),0);
CODES_CHECK(codes_set_long(h, "bitmapPresent", 1),0);
for(i = 0; i < 10; i++) {
values[i]=missing;
}
CODES_CHECK(codes_set_double_array(h, "values", values, values_len),0);
/* 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(outfile);
exit(1);
}
codes_handle_delete(h);
fclose(in);
fclose(out);
return 0;
}
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