time_from_date.c

最大似然估计算法

#include <math.h>
#include <stdio.h>
#include "utc_time.h"

utc_time time_from_date(double date)
{
	int leap;
	int year, tdays;
	
	double ddd, yyddd;

	utc_time Time;

	year = (int) floor(date);
	leap = year%4 == 0 && year%100 != 0 || year%400 == 0;
	tdays = leap + 365;

	ddd = (date - (double) year) * (double) tdays + 1.0;
	yyddd = (double) year * 1000.0 + ddd;

	Time = time_from_yyddd(yyddd);

	return Time;
				
}