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Minor changes to Julian class

feature/19
Daniel Warner 2011-05-28 19:05:46 +00:00
parent 2ef6c635cc
commit b0a25a8be7
2 changed files with 26 additions and 77 deletions
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97
Julian.cpp
View File

@ -15,6 +15,7 @@
#endif
Julian::Julian() {
#ifdef WIN32
SYSTEMTIME st;
GetSystemTime(&st);
@ -39,6 +40,7 @@ Julian::Julian() {
}
Julian::Julian(const Julian& jul) {
date_ = jul.date_;
}
@ -46,6 +48,7 @@ Julian::Julian(const Julian& jul) {
* create julian date given time_t value
*/
Julian::Julian(const time_t t) {
struct tm ptm;
#if WIN32
assert(gmtime_s(&ptm, &t));
@ -66,6 +69,7 @@ Julian::Julian(const time_t t) {
* create julian date from year and day of year
*/
Julian::Julian(int year, double day) {
Initialize(year, day);
}
@ -79,6 +83,7 @@ Julian::Julian(int year, double day) {
* sec: 0-59.99
*/
Julian::Julian(int year, int mon, int day, int hour, int min, double sec) {
Initialize(year, mon, day, hour, min, sec);
}
@ -86,26 +91,32 @@ Julian::Julian(int year, int mon, int day, int hour, int min, double sec) {
* comparison
*/
bool Julian::operator==(const Julian &date) const {
return date_ == date.date_ ? true : false;
}
bool Julian::operator!=(const Julian &date) const {
return date_ == date.date_ ? false : true;
}
bool Julian::operator>(const Julian &date) const {
return date_ > date.date_ ? true : false;
}
bool Julian::operator<(const Julian &date) const {
return date_ < date.date_ ? true : false;
}
bool Julian::operator>=(const Julian &date) const {
return date_ >= date.date_ ? true : false;
}
bool Julian::operator<=(const Julian &date) const {
return date_ <= date.date_ ? true : false;
}
@ -130,28 +141,31 @@ Julian& Julian::operator=(const double b) {
* arithmetic
*/
Julian Julian::operator+(const Timespan& b) const {
Julian result(*this);
result.date_ += b.GetTotalDays();
return result;
}
Julian Julian::operator-(const Timespan& b) const {
Julian result(*this);
result.date_ -= b.GetTotalDays();
return result;
}
std::ostream & operator<<(std::ostream& stream, const Julian& julian) {
std::stringstream out;
struct Julian::DateTimeComponents datetime;
julian.GetDateTime(&datetime);
out << std::right << std::fixed << std::setprecision(3) << std::setfill('0');
julian.ToGregorian(&datetime);
out << std::right << std::fixed << std::setprecision(7) << std::setfill('0');
out << std::setw(4) << datetime.years << "-";
out << std::setw(2) << datetime.months << "-";
out << std::setw(2) << datetime.days << " ";
out << std::setw(2) << datetime.hours << ":";
out << std::setw(2) << datetime.minutes << ":";
out << std::setw(6) << datetime.seconds;
out << std::setw(10) << datetime.seconds;
stream << out.str();
return stream;
}
@ -161,16 +175,13 @@ std::ostream& operator<< (std::ostream& stream, const Julian& julian) {
*/
void Julian::Initialize(int year, double day) {
// Now calculate Julian date
year--;
// Centuries are not leap years unless they divide by 400
int A = (year / 100);
int B = 2 - A + (A / 4);
// 1720994.5 = Oct 30, year -1
double new_years = (int) (365.25 * year) +
(int) (30.6001 * 14) +
double new_years = static_cast<int> (365.25 * year) +
static_cast<int> (30.6001 * 14) +
1720994.5 + B;
date_ = new_years + day;
@ -186,6 +197,7 @@ void Julian::Initialize(int year, double day) {
* sec: 0-59.99
*/
void Julian::Initialize(int year, int mon, int day, int hour, int min, double sec) {
// Calculate N, the day of the year (1..366)
int N;
int F1 = (int) ((275.0 * mon) / 9.0);
@ -204,82 +216,20 @@ void Julian::Initialize(int year, int mon, int day, int hour, int min, double se
Initialize(year, dblDay);
}
/*
* gets year, month and day of month from julian date
*/
void Julian::GetComponent(int& year, int& month, double& dom) const {
double jdAdj = GetDate() + 0.5;
int Z = (int) jdAdj; // integer part
double F = jdAdj - Z; // fractional part
double alpha = (int) ((Z - 1867216.25) / 36524.25);
double A = Z + 1 + alpha - (int) (alpha / 4.0);
double B = A + 1524.0;
int C = (int) ((B - 122.1) / 365.25);
int D = (int) (C * 365.25);
int E = (int) ((B - D) / 30.6001);
dom = B - D - (int) (E * 30.6001) + F;
month = (E < 13.5) ? (E - 1) : (E - 13);
year = (month > 2.5) ? (C - 4716) : (C - 4715);
}
/*
* converts time to time_t
* note: resolution to seconds only
*/
time_t Julian::ToTime() const {
int nYear;
int nMonth;
double dblDay;
GetComponent(nYear, nMonth, dblDay);
// dblDay is the fractional Julian Day (i.e., 29.5577).
// Save the whole number day in nDOM and convert dblDay to
// the fractional portion of day.
int nDOM = (int) dblDay;
dblDay = dblDay - nDOM;
const int SEC_PER_MIN = 60;
const int SEC_PER_HR = 60 * SEC_PER_MIN;
const int SEC_PER_DAY = 24 * SEC_PER_HR;
int secs = (int) ((dblDay * SEC_PER_DAY) + 0.5);
// Create a "struct tm" type.
// NOTE:
// The "struct tm" type has a 1-second resolution. Any fractional
// component of the "seconds" time value is discarded.
struct tm tGMT;
memset(&tGMT, 0, sizeof (tGMT));
tGMT.tm_year = nYear - 1900; // 2001 is 101
tGMT.tm_mon = nMonth - 1; // January is 0
tGMT.tm_mday = nDOM; // First day is 1
tGMT.tm_hour = secs / SEC_PER_HR;
tGMT.tm_min = (secs % SEC_PER_HR) / SEC_PER_MIN;
tGMT.tm_sec = (secs % SEC_PER_HR) % SEC_PER_MIN;
tGMT.tm_isdst = 0; // No conversion desired
time_t tEpoch = mktime(&tGMT);
if (tEpoch != -1) {
// Valid time_t value returned from mktime().
// mktime() expects a local time which means that tEpoch now needs
// to be adjusted by the difference between this time zone and GMT.
// tEpoch = tEpoch - _timezone;
}
return tEpoch;
return static_cast<time_t> ((date_ - 2440587.5) * 86400.0);
}
/*
* Greenwich Mean Sidereal Time
*/
double Julian::ToGreenwichSiderealTime() const {
#if 0
double theta;
double tut1;
@ -328,10 +278,11 @@ double Julian::ToGreenwichSiderealTime() const {
* Local Mean Sideral Time
*/
double Julian::ToLocalMeanSiderealTime(const double& lon) const {
return fmod(ToGreenwichSiderealTime() + lon, kTWOPI);
}
void Julian::GetDateTime(struct DateTimeComponents* datetime) const {
void Julian::ToGregorian(struct DateTimeComponents* datetime) const {
double jdAdj = GetDate() + 0.5;
int Z = (int) jdAdj;

4
Julian.h
View File

@ -44,7 +44,7 @@ public:
double seconds;
};
void GetDateTime(struct DateTimeComponents* datetime) const;
void ToGregorian(struct DateTimeComponents* datetime) const;
time_t ToTime() const;
double ToGreenwichSiderealTime() const;
@ -62,8 +62,6 @@ public:
return date_ - kEPOCH_JAN1_12H_2000;
}
void GetComponent(int& year, int& month, double& dom) const;
double GetDate() const {
return date_;
}