mirror of https://github.com/ecmwf/eccodes.git
104 lines
3.0 KiB
C
104 lines
3.0 KiB
C
/*
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* (C) Copyright 2005- ECMWF.
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*
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* This software is licensed under the terms of the Apache Licence Version 2.0
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* which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
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*
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* In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
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* virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
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*/
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/*
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* C Implementation: grib_set_bitmap
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*
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* Description: how to set a bitmap in a GRIB message
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include "eccodes.h"
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int main(int argc, char** argv)
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{
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int err = 0, i = 0, NUM_MISSING = 10;
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FILE* in = NULL;
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const char* infile = "../../data/regular_latlon_surface.grib1";
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FILE* out = NULL;
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const char* outfile = "out.set_bitmap_c.grib";
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codes_handle* h = NULL;
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const void* buffer = NULL;
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size_t values_len = 0, size = 0;
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long num_of_data_points = 0, num_of_coded_values = 0, num_of_missing = 0;
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double* values;
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const double missing = 1.0e36;
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in = fopen(infile, "rb");
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if (!in) {
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fprintf(stderr, "Error: unable to open input file %s\n", infile);
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return 1;
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}
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out = fopen(outfile, "wb");
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if (!out) {
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fprintf(stderr, "Error: unable to open output file %s\n", outfile);
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fclose(in);
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return 1;
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}
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h = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err);
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if (h == NULL) {
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fprintf(stderr, "Error: unable to create handle from file %s\n", infile);
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fclose(out);
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return 1;
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}
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CODES_CHECK(codes_set_double(h, "missingValue", missing), 0);
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/* get the size of the values array*/
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CODES_CHECK(codes_get_size(h, "values", &values_len), 0);
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values = (double*)malloc(values_len * sizeof(double));
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/* get data values*/
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CODES_CHECK(codes_get_double_array(h, "values", values, &values_len), 0);
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/* enable bitmap */
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CODES_CHECK(codes_set_long(h, "bitmapPresent", 1), 0);
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/* set some values to be missing */
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for (i = 0; i < NUM_MISSING; i++) {
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values[i] = missing;
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}
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/* set the values (the bitmap will be automatically built) */
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CODES_CHECK(codes_set_double_array(h, "values", values, values_len), 0);
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/* sanity checks */
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CODES_CHECK(codes_get_long(h, "numberOfDataPoints", &num_of_data_points), 0);
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CODES_CHECK(codes_get_long(h, "numberOfCodedValues", &num_of_coded_values), 0);
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CODES_CHECK(codes_get_long(h, "numberOfMissing", &num_of_missing), 0);
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assert(num_of_data_points == values_len);
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assert(num_of_coded_values == num_of_data_points - num_of_missing);
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assert(num_of_missing == NUM_MISSING);
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/* get the coded message in a buffer */
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CODES_CHECK(codes_get_message(h, &buffer, &size), 0);
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/* write the buffer in a file*/
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if (fwrite(buffer, 1, size, out) != size) {
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perror(outfile);
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exit(1);
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}
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codes_handle_delete(h);
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free(values);
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fclose(in);
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fclose(out);
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return 0;
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}
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