mirror of https://github.com/ecmwf/eccodes.git
81 lines
1.8 KiB
C
Executable File
81 lines
1.8 KiB
C
Executable File
/*
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* Copyright 2005-2017 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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#include <stdio.h>
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#include "grib_api_internal.h"
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double min = -1.0000000001;
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double max = -1.00000000001;
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double scale ;
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double p(double ref1,double ref2)
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{
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double scale = (max-ref1) / 65535;
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unsigned long pack = (unsigned long)(((max - ref1)/scale)+0.5);
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double unpack = pack*scale + ref2;
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printf(" max: %04X %0.20f %0.20f\n",pack,unpack,max-unpack);
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pack = (unsigned long)(((min- ref1)/scale)+0.5);
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unpack = pack*scale + ref2;
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printf(" min: %04X %0.20f %0.20f\n",pack,unpack,min-unpack);
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printf("\n");
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return unpack;
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}
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int main(int argc, char *argv[])
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{
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#if 1
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unsigned long i = 0;
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assert(grib_ieee_to_long(grib_long_to_ieee(i)) == i);
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for(i = 1; i < 0x7fffffff; i++)
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{
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unsigned long j = i | 0x80000000;
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if(grib_ieee_to_long(grib_long_to_ieee(i)) != i)
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{
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printf("i=%ld i=%lx e=%g x=%lx\n",i,i,grib_long_to_ieee(i),grib_ieee_to_long(grib_long_to_ieee(i)));
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assert(grib_ieee_to_long(grib_long_to_ieee(i)) == i);
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}
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assert(grib_ieee_to_long(grib_long_to_ieee(j)) == j);
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if((i%100000) == 0)
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printf("i = %08lx %08lx %g %g\n",i,j,grib_long_to_ieee(i),grib_long_to_ieee(j));
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}
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#else
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double ref1 = grib_long_to_ieee(grib_ieee_to_long(min));
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double ref2 = grib_nearest_smaller_ieee_float(min);
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double a = p(min,ref1);
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double b = p(min,ref2);
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double c = p(ref1,ref1);
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double d = p(ref2,ref2);
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assert(min<max);
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/* */
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#endif
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return 0;
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}
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