/* * Copyright 2005-2016 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. */ #include #include "grib_api_internal.h" double min = -1.0000000001; double max = -1.00000000001; double scale ; double p(double ref1,double ref2) { double scale = (max-ref1) / 65535; unsigned long pack = (unsigned long)(((max - ref1)/scale)+0.5); double unpack = pack*scale + ref2; printf(" max: %04X %0.20f %0.20f\n",pack,unpack,max-unpack); pack = (unsigned long)(((min- ref1)/scale)+0.5); unpack = pack*scale + ref2; printf(" min: %04X %0.20f %0.20f\n",pack,unpack,min-unpack); printf("\n"); return unpack; } int main(int argc, char *argv[]) { #if 1 unsigned long i = 0; assert(grib_ieee_to_long(grib_long_to_ieee(i)) == i); for(i = 1; i < 0x7fffffff; i++) { unsigned long j = i | 0x80000000; if(grib_ieee_to_long(grib_long_to_ieee(i)) != i) { 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))); assert(grib_ieee_to_long(grib_long_to_ieee(i)) == i); } assert(grib_ieee_to_long(grib_long_to_ieee(j)) == j); if((i%100000) == 0) printf("i = %08lx %08lx %g %g\n",i,j,grib_long_to_ieee(i),grib_long_to_ieee(j)); } #else double ref1 = grib_long_to_ieee(grib_ieee_to_long(min)); double ref2 = grib_nearest_smaller_ieee_float(min); double a = p(min,ref1); double b = p(min,ref2); double c = p(ref1,ref1); double d = p(ref2,ref2); assert(min