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26 lines
619 B
C
26 lines
619 B
C
#include "predict.h"
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#include <stdio.h>
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#include <time.h>
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#include <math.h>
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#include "defs.h"
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#define JULIAN_START_OF_DAY 315446400
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predict_julian_date_t predict_to_julian(time_t input_time)
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{
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//get number of seconds since 1979-12-31 00:00:00 UTC, convert to days
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double seconds = difftime(input_time, JULIAN_START_OF_DAY);
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return seconds / SECONDS_PER_DAY;
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}
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predict_julian_date_t predict_to_julian_double(double time)
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{
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return predict_to_julian(time) + (fmod(time, 1.0) / SECONDS_PER_DAY);
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}
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time_t predict_from_julian(predict_julian_date_t date)
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{
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return date * SECONDS_PER_DAY + JULIAN_START_OF_DAY;
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}
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