Swift4 经纬度计算日出日落时间
swift 日出日落时间，真个也是从OC转过来的，可能不是很好，但是能用。
import UIKit class PGSun: NSObject { struct Sunriseset { var sunrise = "07:00" // 日出 var sunset = "18:30" // 日落 init(sunrise:String, sunset:String) { self.sunrise = sunrise self.sunset = sunset } } var start: Double = 0.0 var sRA: Double = 0.0 var sdec: Double = 0.0 var sr: Double = 0.0 var lon: Double = 0.0 var end: Double = 0.0 private let Inv360: Double = 1.0 / 360.0 private let Degrad: Double = .pi / 180.0 private let Radge: Double = 180.0 / .pi /// 根据经纬度计算日出和日落时间 -误差2分钟 /// /// - Parameters: /// - Returns: Sunriseset class func sun(longitude:Double, latitude:Double)->Sunriseset{ let sun = PGSun() return sun.getSunTimeAtDate(d: Date(), longitude: longitude, latitude: latitude) } func getSunTimeAtDate(d:Date , longitude:Double ,latitude:Double)->Sunriseset{ let xcts: Int = days(since_2000_Jan_0: d) let dic = getSunTime(xcts, lon: longitude, lat: latitude) return dic } func getSunTime(_ day: Int, lon longitude: Double, lat latitude: Double) -> Sunriseset { _ = self.sunRiset(day, long:longitude, lat:latitude ,altit: -35.0 / 60.0, limb:1, trise:self.start, tset:self.end) let sunrise = toLocalTime(self.start) let sunset = toLocalTime(self.end) let sun = Sunriseset(sunrise: sunrise, sunset: sunset) return sun } func toLocalTime(_ utTime:Double)-> String { var hour = Int(floor(utTime)) var temp = utTime - Double(hour) hour += 8; temp = temp * 60; let minute = Int(floor(temp)) return String(format: "%02d:%02d", hour,minute) } func days(since_2000_Jan_0 d: Date) -> Int { //距离2000-01-01的天数 let dateStr = "2000-01-01" let dateFormatter = DateFormatter() dateFormatter.dateFormat = "yyyy-MM-dd" let date: Date? = dateFormatter.date(from: dateStr) var time: TimeInterval? = nil if let aDate = date { time = d.timeIntervalSince(aDate) } let days = (Int(time ?? 0)) / (3600 * 24) return days } func sunRiset(_ day:Int, long longitude:Double, lat:Double ,altit:Double, limb upper_limb:Int, trise:Double, tset:Double)->Int{ var altit = altit var d = 0.0/* Days since 2000 Jan 0.0 (negative before) */ //以历元2000.0起算的日数。 var sradius = 0.0 /* Sun's apparent radius */ //太阳视半径，约16分（受日地距离、大气折射等诸多影响） var t = 0.0 /* Diurnal arc */ //周日弧，太阳一天在天上走过的弧长。 var tsouth = 0.0 /* Time when Sun is at south */ var sidtime = 0.0 /* Local sidereal time */ //当地恒星时，即地球的真实自转周期。比平均太阳日（日常时间）长3分56秒。 var rc = 0; /* Return cde from function - usually 0 */ /* Compute d of 12h local mean solar time */ d = Double(day)/* Days_since_2000_Jan_0(date)*/ + 0.5 - longitude / 360.0; //计算观测地当日中午时刻对应2000.0起算的日数。 /* Compute local sideral time of this moment */ sidtime = self.revolution(self.GMST0(d) + 180.0 + longitude) //计算同时刻的当地恒星时（以角度为单位）。以格林尼治为基准，用经度差校正。 /* Compute Sun's RA + Decl at this moment */ self.Sun_RA_dec(d, ra:self.sRA, dec:self.sdec, r:self.sr); // Sun_RA_dec(d, sRA,sdec,sr); //计算同时刻太阳赤经赤纬。 /* Compute time when Sun is at south - in hours UT */ tsouth = 12.0 - self.rev180(sidtime - self.sRA) / 15.0; // tsouth = 12.0 - Rev180(sidtime - sRA) / 15.0; //计算太阳日的正午时刻，以世界时（格林尼治平太阳时）的小时计。 /* Compute the Sun's apparent radius, degrees */ sradius = 0.2666 / self.sr; //太阳视半径。0.2666是一天文单位处的太阳视半径（角度）。 /* Do correction to upper limb, if necessary */ if upper_limb != 0 { altit -= sradius; //如果要用上边缘，就要扣除一个视半径。 } /* Compute the diurnal arc that the Sun traverses to reach */ //计算周日弧。直接利用球面三角公式。如果碰到极昼极夜问题，同前处理。 /* the specified altitide altit: */ var cost:Double = 0 cost = (self.sind(altit) - self.sind(lat)*self.sind(self.sdec))/(self.cosd(lat) * self.cosd(self.sdec)); // cost = (Sind(altit) - Sind(lat) * Sind(sdec)) / // (Cosd(lat) * Cosd(sdec)); if (cost >= 1.0) { rc = -1; t = 0.0; } else { if (cost <= -1.0) { rc = +1; t = 12.0; /* Sun always above altit */ } else{ // t = Acosd(cost) / 15.0; /* The diurnal arc, hours */ t = self.acosd(cost) / 15.0; } } /* Store rise and set times - in hours UT */ self.start = tsouth - t; self.end = tsouth + t; return rc; } func Sun_RA_dec(_ d: Double, ra RA: Double, dec: Double, r: Double) { var obl_ecl: Double = 0 var x: Double = 0 var y: Double = 0 var z: Double = 0 sunpos(d, lon: lon, r: r) //计算太阳的黄道坐标。 x = sr * cosd(lon) y = sr * sind(lon) //计算太阳的直角坐标。 obl_ecl = 23.4393 - 3.563E-7 * d //黄赤交角，同前。 z = y * sind(obl_ecl) y = y * cosd(obl_ecl) //把太阳的黄道坐标转换成赤道坐标（暂改用直角坐标）。 sRA = atan2d(y, x: x) sdec = atan2d(z, x: sqrt(x * x + y * y)) //最后转成赤道坐标。显然太阳的位置是由黄道坐标方便地直接确定的，但必须转换到赤 //道坐标里才能结合地球的自转确定我们需要的白昼长度。 } func sunpos(_ d: Double, lon: Double, r: Double) { var lon = lon var M: Double = 0 var w: Double = 0 var e: Double = 0 var E: Double = 0 var x: Double = 0 var y: Double = 0 var v: Double = 0 //真近点角，太阳在任意时刻的真实近点角。 M = revolution(356.0470 + 0.9856002585 * d) //自变量的组成：2000.0时刻太阳黄经为356.0470度,此后每天约推进一度（360度/365天 w = 282.9404 + 4.70935E-5 * d //近日点的平均黄经。 e = 0.016709 - 1.151E-9 * d //地球公转椭圆轨道离心率的时间演化。以上公式和黄赤交角公式一样，不必深究。 E = M + e * Double(Radge) * sind(M) * (1.0 + e * cosd(M)) x = cosd(E) - e y = sqrt(1.0 - e * e) * sind(E) sr = sqrt(x * x + y * y) v = atan2d(y, x: x) lon = v + w self.lon = lon if lon >= 360.0 { lon -= 360.0 self.lon = lon } } func revolution(_ x: Double) -> Double { return x - 360.0 * floor(x * Double(Inv360)) } func rev180(_ x: Double) -> Double { return x - 360.0 * floor(x * Double(Inv360) + 0.5) } func GMST0(_ d: Double) -> Double { var sidtim0: Double sidtim0 = revolution((180.0 + 356.0470 + 282.9404) + (0.9856002585 + 4.70935E-5) * d) return sidtim0 } func sind(_ x: Double) -> Double { return sin(x * Double(Degrad)) } func cosd(_ x: Double) -> Double { return cos(x * Double(Degrad)) } func acosd(_ x: Double) -> Double { return Double(Radge * acos(x)) } func atan2d(_ y: Double, x: Double) -> Double { return Double(Radge * atan2(y, x)) } }
