mirror of https://github.com/ecmwf/eccodes.git
143 lines
4.4 KiB
C
Executable File
143 lines
4.4 KiB
C
Executable File
/*
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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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#include <stdio.h>
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#include <assert.h>
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#include <float.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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typedef unsigned long (*ieee_to_long_proc) (double);
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typedef double (*long_to_ieee_proc) (unsigned long);
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#if 0
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static void test(unsigned long input, ieee_to_long_proc ieee_to_long, long_to_ieee_proc long_to_ieee)
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{
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double x1 = long_to_ieee(input);
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unsigned long num2 = ieee_to_long(x1);
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printf("\nconv input=%ld to double=%.10f (%g) and back => %ld\n", input, x1, x1, num2);
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if (num2!=input) printf("ERROR: input=%ld not equal!!!\n", input);
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}
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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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#endif
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/* generate a random floating point number from min to max */
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static double randfrom(double minimum, double maximum)
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{
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double range = (maximum - minimum);
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double div = RAND_MAX / range;
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return minimum + (rand() / div);
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}
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/* Return 1 on success, 0 on failure */
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static int test_doubles(ieee_to_long_proc ieee_to_long, long_to_ieee_proc long_to_ieee)
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{
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const double tolerance = 1e-7;
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const double increment = 1;
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const double max_value = 10 * 1000 * 1000;
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const double min_value = -max_value;
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double d = max_value;
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int num_errors = 0;
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int num_trials = 0;
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double max_reldiff = -DBL_MAX;
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while (d > min_value) {
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double start = randfrom(0.7,1) * d;
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unsigned long a = ieee_to_long(start);
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double end = long_to_ieee(a);
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num_trials++;
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if (start != 0.0) {
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double reldiff = fabs(end - start)/start;
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if (reldiff > tolerance) {
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printf("Error: %.10f (diff=%.10f)\n", start, reldiff);
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num_errors ++;
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} else {
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/*printf("Success: %.10f (diff=%.10f)\n", start, reldiff);*/
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}
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if (reldiff > max_reldiff) max_reldiff = reldiff;
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}
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d -= increment;
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}
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printf("trials = %d, errors = %d\n", num_trials,num_errors);
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printf("max reldiff = %g\n", max_reldiff);
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return num_errors==0 ? 1 : 0;
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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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printf("Test doubles with grib_ieee_to_long/grib_long_to_ieee...\n");
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assert( test_doubles(grib_ieee_to_long, grib_long_to_ieee)==1 );
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printf("Test doubles with grib_ieee64_to_long/grib_long_to_ieee64...\n");
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assert( test_doubles(grib_ieee64_to_long, grib_long_to_ieee64)==1 );
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printf("Test integers...\n");
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/* test(3242539564, grib_ieee_to_long, grib_long_to_ieee); This fails! */
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assert(grib_ieee_to_long(grib_long_to_ieee(i)) == i);
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/* The minimum value for which we can convert a long to ieee and back is 0x800000 */
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/* The maximum value for which we can convert a long to ieee and back is 0x7f800000 */
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for(i = 0x800000; i < 0x7f800000; 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=%lu 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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assert(0);
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}
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/*if(grib_ieee_to_long(grib_long_to_ieee(j)) != j)
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{
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printf("j=%ld i=%lx e=%g x=%lx\n",j,j,grib_long_to_ieee(j),grib_ieee_to_long(grib_long_to_ieee(j)));
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}
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if ((i%1000000) == 0) {
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printf("i = %08lx(%ld) %08lx(%ld) %g %g\n", i,i,j,j,grib_long_to_ieee(i),grib_long_to_ieee(j));
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}*/
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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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#endif
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printf("ALL DONE\n");
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return 0;
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}
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