mirror of https://github.com/ecmwf/eccodes.git
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
#include <assert.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#include "grib_api.h"
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int main(int argc, char *argv[])
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{
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int ret=0;
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FILE* f;
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size_t size;
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grib_handle* h=NULL;
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double* values=NULL;
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long numberOfPointsAlongAParallel,numberOfPointsAlongAMeridian,numberOfPoints,i,j,k;
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char* filename="out.grib";
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const void* buffer=NULL;
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/* Create a grib handle from template*/
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h = grib_handle_new_from_template(0,"GRIB1");
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if(!h) {
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printf("ERROR: Unable to create grib handle\n");
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exit(1);
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}
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/* set values as appropriate in the grib handle header */
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CHECK(grib_set_long(h,"gribTablesVersionNo", 210));
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CHECK(grib_set_long(h,"indicatorOfParameter",80 ));
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CHECK(grib_set_long(h,"indicatorOfTypeOfLevel",1 ));
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CHECK(grib_set_long(h,"topLevel",0));
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CHECK(grib_set_long(h,"bottomLevel",0));
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CHECK(grib_set_long(h,"dataDate",20021201 ));
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CHECK(grib_set_long(h,"dataTime",1200 ));
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CHECK(grib_set_double(h,"latitudeOfFirstGridPointInDegrees",10));
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CHECK(grib_set_double(h,"longitudeOfFirstGridPointInDegrees",-10));
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CHECK(grib_set_double(h,"latitudeOfLastGridPointInDegrees",-10));
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CHECK(grib_set_double(h,"longitudeOfLastGridPointInDegrees",10));
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CHECK(grib_set_double(h,"jDirectionIncrementInDegrees",0.5));
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CHECK(grib_set_double(h,"iDirectionIncrementInDegrees",0.5));
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/* get number of points calculated automatically by the grib_api */
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CHECK(grib_get_long( h,"numberOfPointsAlongAParallel",&numberOfPointsAlongAParallel));
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CHECK(grib_get_long( h,"numberOfPointsAlongAMeridian",&numberOfPointsAlongAMeridian));
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numberOfPoints=numberOfPointsAlongAMeridian*numberOfPointsAlongAMeridian;
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/* allocate the values array */
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values=(double*)malloc(numberOfPoints*sizeof(double));
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/* load the values array */
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for (j=0;j<numberOfPointsAlongAMeridian;j++) {
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for (i=0;i<numberOfPointsAlongAParallel;i++) {
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k=i+numberOfPointsAlongAParallel*j;
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values[k]=50;
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}
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}
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/* set values in the grib */
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grib_set_double_array( h,"values",values,numberOfPoints);
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/* write grib to file */
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f = fopen(filename,"w");
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if(!f) {
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perror(filename);
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exit(1);
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}
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grib_get_message(h,&buffer,&size);
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if(fwrite(buffer,1,size,f) != size) {
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perror(filename);
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exit(1);
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}
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if(fclose(f)) {
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perror(filename);
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exit(1);
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}
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grib_handle_delete( h);
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return ret;
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}
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