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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 use an iterator on lat/lon/values and query the bitmap
* for missing values
* (rather than compare each value with the missingValue key)
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "eccodes.h"
static void usage(const char* prog)
{
printf("Usage: %s grib_file\n", prog);
exit(1);
}
int main(int argc, char** argv)
{
FILE* in = NULL;
int err = 0;
double lat, lon, value;
int n = 0;
size_t bmp_len = 0, values_len = 0;
char* filename = NULL;
long bitmapPresent = 0;
long* bitmap = NULL;
double* values = NULL;
codes_handle* h = NULL;
codes_iterator* iter = NULL;
if (argc != 2) usage(argv[0]);
filename = argv[1];
in = fopen(filename, "rb");
if (!in) {
fprintf(stderr, "ERROR: unable to open file %s\n", filename);
return 1;
}
while ((h = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err)) != NULL) {
if (err != CODES_SUCCESS) CODES_CHECK(err, 0);
CODES_CHECK(codes_get_long(h, "bitmapPresent", &bitmapPresent), 0);
if (bitmapPresent) {
CODES_CHECK(codes_get_size(h, "bitmap", &bmp_len), 0);
bitmap = (long*)malloc(bmp_len * sizeof(long));
CODES_CHECK(codes_get_long_array(h, "bitmap", bitmap, &bmp_len), 0);
printf("Bitmap is present. Num = %zu\n", bmp_len);
}
/* sanity check. Number of values must match number in bitmap */
CODES_CHECK(codes_get_size(h, "values", &values_len), 0);
values = (double*)malloc(values_len * sizeof(double));
CODES_CHECK(codes_get_double_array(h, "values", values, &values_len), 0);
if (bitmapPresent) {
assert(values_len == bmp_len);
}
/* a new iterator on lat/lon/values is created from the message handle h */
iter = codes_grib_iterator_new(h, 0, &err);
if (err != CODES_SUCCESS) CODES_CHECK(err, 0);
n = 0;
/* loop on all the lat/lon/values. Only print non-missing values */
while (codes_grib_iterator_next(iter, &lat, &lon, &value)) {
/* consult bitmap to see if the n'th value is missing */
int is_missing_val = (bitmapPresent && bitmap[n] == 0);
if (!is_missing_val) {
printf("- %d - lat=%f lon=%f value=%f\n", n, lat, lon, value);
}
n++;
}
/* check number of elements in iterator matches value count */
assert(n == values_len);
codes_grib_iterator_delete(iter);
codes_handle_delete(h);
}
fclose(in);
return 0;
}
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