北斗周，周内秒，约化儒略日，协调世界时之间互相转换C++代码，用结构体，.h.cpp

以下是一个简单的C++代码示例，可用于将北斗周、周内秒、约化儒略日和协调世界时之间进行转换。这个代码使用结构体和头文件/源文件分离的形式。

time.h:

#ifndef TIME_H
#define TIME_H

struct Time {
    int year;
    int month;
    int day;
    int hour;
    int minute;
    double second;
};

int week_seconds_to_jd(int week, double seconds);
int jd_to_week_seconds(double jd, int& week);
Time jd_to_utc(double jd);
double utc_to_jd(Time t);

#endif

time.cpp:

#include "time.h"
#include <cmath>

const double JD_J2000 = 2451545.0;

const double SECONDS_PER_DAY = 86400.0;
const double SECONDS_PER_WEEK = 604800.0;

int week_seconds_to_jd(int week, double seconds) {
    return (int)(JD_J2000 + week * 7.0 + seconds / SECONDS_PER_DAY);
}

int jd_to_week_seconds(double jd, int& week) {
    double days = jd - JD_J2000;
    week = (int)(days / 7.0);
    return (int)(fmod(days, 7.0) * SECONDS_PER_DAY);
}

Time jd_to_utc(double jd) {
    int y, m, d;
    double seconds;
    
    double jd0 = floor(jd + 0.5);
    double c = jd0 + 0.5;
    double x = floor((c - 1867216.25) / 36524.25);
    double a = c + 1.0 + x - floor(x / 4.0);
    double b = a + 1524.0;
    double c1 = floor((b - 122.1) / 365.25);
    double d1 = floor(365.25 * c1);
    double e = floor((b - d1) / 30.6001);
    
    d = (int)(b - d1 - floor(30.6001 * e));
    m = (int)(e - (e > 13.5 ? 13.0 : 1.0));
    y = (int)(c1 - (m > 2.5 ? 4716.0 : 4715.0));
    
    double frac = jd + 0.5 - jd0;
    seconds = frac * SECONDS_PER_DAY;
    
    Time t = { y, m, d, (int)floor(seconds / 3600.0), (int)floor(fmod(seconds, 3600.0) / 60.0), fmod(seconds, 60.0) };
    return t;
}

double utc_to_jd(Time t) {
    int y = t.year;
    int m = t.month;
    int d = t.day;
    int h = t.hour;
    int mi = t.minute;
    double s = t.second;
    
    if (m <= 2) {
        m += 12;
        y--;
    }
    
    int a = (int)floor(y / 100.0);
    int b = 2 - a + (int)floor(a / 4.0);
    
    double jd = floor(365.25 * (y + 4716.0)) + floor(30.6001 * (m + 1)) + d + b - 1524.5;
    double frac = (h + mi / 60.0 + s / 3600.0) / 24.0;
    
    return jd + frac;
}

使用示例：

#include <iostream>
#include "time.h"

int main() {
    int week = 2127;
    double seconds = 345678.9;
    
    int jd = week_seconds_to_jd(week, seconds);
    std::cout << "JD: " << jd << std::endl;
    
    int week2;
    int seconds2 = jd_to_week_seconds(jd, week2);
    std::cout << "Week: " << week2 << ", Seconds: " << seconds2 << std::endl;
    
    Time t = jd_to_utc(jd);
    std::cout << "UTC: " << t.year << "-" << t.month << "-" << t.day << " " << t.hour << ":" << t.minute << ":" << t.second << std::endl;
    
    double jd2 = utc_to_jd(t);
    std::cout << "JD: " << jd2 << std::endl;
    
    return 0;
}