我想对timestamp
PostgreSQL 表中的数据类型进行分类,以确定它们是否可以被视为“白天”或“晚上”。换句话说,我希望能够在给定特定 GPS 位置的情况下准确计算日出和日落时间。
我知道 plpgsql 和 plpython。
我想对timestamp
PostgreSQL 表中的数据类型进行分类,以确定它们是否可以被视为“白天”或“晚上”。换句话说,我希望能够在给定特定 GPS 位置的情况下准确计算日出和日落时间。
我知道 plpgsql 和 plpython。
看看这些链接:
我知道这已经过时了,但我想我会分享,因为我没有找到快速的解决方案。这使用了 Sun 类(见下文),我通过以下链接构建了该类。
from Sun import Sun
coords = {'longitude' : 145, 'latitude' : -38 }
sun = Sun()
# Sunrise time UTC (decimal, 24 hour format)
print sun.getSunriseTime( coords )['decimal']
# Sunset time UTC (decimal, 24 hour format)
print sun.getSunsetTime( coords )['decimal']
至少在我住的地方,它似乎在几分钟内是准确的。为了获得更高的准确性,calcSunTime() 方法中的 zenith 参数可以使用微调。有关更多信息,请参阅上面的链接。
# save this as Sun.py
import math
import datetime
class Sun:
def getSunriseTime( self, coords ):
return self.calcSunTime( coords, True )
def getSunsetTime( self, coords ):
return self.calcSunTime( coords, False )
def getCurrentUTC( self ):
now = datetime.datetime.now()
return [ now.day, now.month, now.year ]
def calcSunTime( self, coords, isRiseTime, zenith = 90.8 ):
# isRiseTime == False, returns sunsetTime
day, month, year = self.getCurrentUTC()
longitude = coords['longitude']
latitude = coords['latitude']
TO_RAD = math.pi/180
#1. first calculate the day of the year
N1 = math.floor(275 * month / 9)
N2 = math.floor((month + 9) / 12)
N3 = (1 + math.floor((year - 4 * math.floor(year / 4) + 2) / 3))
N = N1 - (N2 * N3) + day - 30
#2. convert the longitude to hour value and calculate an approximate time
lngHour = longitude / 15
if isRiseTime:
t = N + ((6 - lngHour) / 24)
else: #sunset
t = N + ((18 - lngHour) / 24)
#3. calculate the Sun's mean anomaly
M = (0.9856 * t) - 3.289
#4. calculate the Sun's true longitude
L = M + (1.916 * math.sin(TO_RAD*M)) + (0.020 * math.sin(TO_RAD * 2 * M)) + 282.634
L = self.forceRange( L, 360 ) #NOTE: L adjusted into the range [0,360)
#5a. calculate the Sun's right ascension
RA = (1/TO_RAD) * math.atan(0.91764 * math.tan(TO_RAD*L))
RA = self.forceRange( RA, 360 ) #NOTE: RA adjusted into the range [0,360)
#5b. right ascension value needs to be in the same quadrant as L
Lquadrant = (math.floor( L/90)) * 90
RAquadrant = (math.floor(RA/90)) * 90
RA = RA + (Lquadrant - RAquadrant)
#5c. right ascension value needs to be converted into hours
RA = RA / 15
#6. calculate the Sun's declination
sinDec = 0.39782 * math.sin(TO_RAD*L)
cosDec = math.cos(math.asin(sinDec))
#7a. calculate the Sun's local hour angle
cosH = (math.cos(TO_RAD*zenith) - (sinDec * math.sin(TO_RAD*latitude))) / (cosDec * math.cos(TO_RAD*latitude))
if cosH > 1:
return {'status': False, 'msg': 'the sun never rises on this location (on the specified date)'}
if cosH < -1:
return {'status': False, 'msg': 'the sun never sets on this location (on the specified date)'}
#7b. finish calculating H and convert into hours
if isRiseTime:
H = 360 - (1/TO_RAD) * math.acos(cosH)
else: #setting
H = (1/TO_RAD) * math.acos(cosH)
H = H / 15
#8. calculate local mean time of rising/setting
T = H + RA - (0.06571 * t) - 6.622
#9. adjust back to UTC
UT = T - lngHour
UT = self.forceRange( UT, 24) # UTC time in decimal format (e.g. 23.23)
#10. Return
hr = self.forceRange(int(UT), 24)
min = round((UT - int(UT))*60,0)
return {
'status': True,
'decimal': UT,
'hr': hr,
'min': min
}
def forceRange( self, v, max ):
# force v to be >= 0 and < max
if v < 0:
return v + max
elif v >= max:
return v - max
return v
使用Astral(当前版本 1.6)。文档中的第一个示例显示了给定位置的日出和日落计算。具有自定义纬度和经度的更简单示例是:
from datetime import date
import astral
loc = astral.Location(('Bern', 'Switzerland', 46.95, 7.47, 'Europe/Zurich', 510))
for event, time in loc.sun(date.today()).items():
print(event, 'at', time)
给出:
noon at 2018-03-12 12:39:59+01:00
sunset at 2018-03-12 18:30:11+01:00
sunrise at 2018-03-12 06:49:47+01:00
dusk at 2018-03-12 20:11:39+01:00
dawn at 2018-03-12 05:08:18+01:00
然后,您可以以此为起点,使用 plpython 而不是 plr 编写自己的 postgres(或 postgis)函数。
所以我知道这是一个古老的问题,但我仍然需要在 Postgres 中实际计算它。因此,我将 oortCloud 的答案移植到 PL/pgSQL。也许它对某人有用:
CREATE OR REPLACE FUNCTION FORCE_RANGE(
v DOUBLE PRECISION,
max DOUBLE PRECISION
) RETURNS DOUBLE PRECISION AS $$
BEGIN
IF v < 0 THEN
RETURN v + max;
ELSEIF v >= max THEN
return v - max;
END IF;
return v;
END; $$
LANGUAGE plpgsql IMMUTABLE;
CREATE OR REPLACE FUNCTION RISE_SET_TIME(
latitude DOUBLE PRECISION,
longitude DOUBLE PRECISION,
isRiseTime BOOL,
as_of TIMESTAMPTZ,
zenith DOUBLE PRECISION DEFAULT 90.8
)
RETURNS TIMESTAMPTZ AS $$
DECLARE as_of_utc TIMESTAMPTZ;
DECLARE as_of_year INT;
DECLARE as_of_month INT;
DECLARE as_of_day INT;
DECLARE N1 INT;
DECLARE N2 INT;
DECLARE N3 INT;
DECLARE N INT;
DECLARE longitude_hour DOUBLE PRECISION;
DECLARE M DOUBLE PRECISION;
DECLARE t DOUBLE PRECISION;
DECLARE L DOUBLE PRECISION;
DECLARE RA DOUBLE PRECISION;
DECLARE Lquadrant INT;
DECLARE RAquadrant INT;
DECLARE sinDec DOUBLE PRECISION;
DECLARE cosDec DOUBLE PRECISION;
DECLARE cosH DOUBLE PRECISION;
DECLARE H DOUBLE PRECISION;
DECLARE UT DOUBLE PRECISION;
DECLARE hr INT;
DECLARE min INT;
BEGIN
as_of_utc = as_of at time zone 'utc';
as_of_year = EXTRACT(YEAR FROM as_of_utc);
as_of_month = EXTRACT(MONTH FROM as_of_utc);
as_of_day = EXTRACT(DAY FROM as_of_utc);
-- 1. first calculate the day of the year
N1 = FLOOR(275.0 * as_of_month / 9.0);
N2 = FLOOR((as_of_month + 9) / 12.0);
N3 = (1 + FLOOR((as_of_year - 4 * FLOOR(as_of_year / 4.0) + 2) / 3.0));
N = N1 - (N2 * N3) + as_of_day - 30;
-- 2. convert the longitude to hour value and calculate an approximate time
longitude_hour = longitude / 15.0;
IF isRiseTime THEN
t = N + ((6 - longitude_hour) / 24.);
ELSE
t = N + ((18 - longitude_hour) / 24.);
END IF;
-- 3. calculate the Sun's mean anomaly
M = (0.9856 * t) - 3.289;
-- 4. calculate the Sun's true longitude
L = M + (1.916 * SIN(RADIANS(M))) + (0.020 * SIN(RADIANS(2 * M))) + 282.634;
-- NOTE: L adjusted into the range [0,360)
L = FORCE_RANGE(L, 360.0);
-- 5a. calculate the Sun's right ascension
RA = (1/RADIANS(1)) * ATAN(0.91764 * TAN(RADIANS(L)));
RA = FORCE_RANGE( RA, 360 ); -- NOTE: RA adjusted into the range [0,360);
-- 5b. right ascension value needs to be in the same quadrant as L
Lquadrant = FLOOR(L/90.) * 90;
RAquadrant = FLOOR(RA/90.) * 90;
RA = RA + (Lquadrant - RAquadrant);
-- 5c. right ascension value needs to be converted into hours
RA = RA / 15.0;
-- 6. calculate the Sun's declination
sinDec = 0.39782 * SIN(RADIANS(L));
cosDec = COS(ASIN(sinDec));
-- 7a. calculate the Sun's local hour angle
cosH = (COS(RADIANS(zenith)) - (sinDec * SIN(RADIANS(latitude)))) / (cosDec * COS(RADIANS(latitude)));
IF cosH > 1 THEN
RAISE NOTICE 'The sun never rises on this location on the specified date';
RETURN NULL;
END IF;
IF cosH < -1 THEN
RAISE NOTICE 'The sun never sets on this location on the specified date';
RETURN NULL;
END IF;
-- 7b. finish calculating H and convert into hours
IF isRiseTime THEN
H = 360 - (1/RADIANS(1)) * ACOS(cosH);
ELSE
H = (1/RADIANS(1)) * ACOS(cosH);
END IF;
H = H / 15.0;
-- calculate local mean time of rising/setting
T = H + RA - (0.06571 * t) - 6.622;
-- 9. adjust back to UTC
UT = T - longitude_hour;
UT = FORCE_RANGE( UT, 24); -- UTC time in decimal format (e.g. 23.23)
-- 10. Return
hr = FORCE_RANGE(UT::INT, 24);
min = ROUND((UT - UT::INT) * 60);
-- Enable for debugging purposes:
-- RAISE NOTICE 'as_of_utc: %', as_of_utc;
-- RAISE NOTICE 'as_of_year: %', as_of_year;
-- RAISE NOTICE 'as_of_month: %', as_of_month;
-- RAISE NOTICE 'as_of_day: %', as_of_day;
-- RAISE NOTICE 'N1: %', N1;
-- RAISE NOTICE 'N2: %', N2;
-- RAISE NOTICE 'N3: %', N3;
-- RAISE NOTICE 'N: %', N;
-- RAISE NOTICE 'longitude_hour: %', longitude_hour;
-- RAISE NOTICE 'M: %', M;
-- RAISE NOTICE 't: %', t;
-- RAISE NOTICE 'L: %', L;
-- RAISE NOTICE 'RA: %', RA;
-- RAISE NOTICE 'Lquadrant: %', Lquadrant;
-- RAISE NOTICE 'RAquadrant: %', RAquadrant;
-- RAISE NOTICE 'sinDec: %', sinDec;
-- RAISE NOTICE 'cosDec: %', cosDec;
-- RAISE NOTICE 'cosH: %', cosH;
-- RAISE NOTICE 'H: %', H;
-- RAISE NOTICE 'UT: %', UT;
-- RAISE NOTICE 'hr: %', hr;
-- RAISE NOTICE 'min: %', min;
return as_of_utc::DATE + (INTERVAL '1 hour' * hr) + (INTERVAL '1 minute' * min);
END; $$
LANGUAGE plpgsql IMMUTABLE;
示例使用:
SELECT
RISE_SET_TIME(39.399872, -8.224454, TRUE, NOW()) AS rise,
RISE_SET_TIME(39.399872, -8.224454, FALSE, NOW()) AS set
;
我用它来计算日出、日落、黎明和黄昏的时间。
只需要将 X 替换为您的坐标即可。请注意,返回的时间是 UTC,因此您需要在需要时添加您的特定时区小时。
request = Request('http://api.sunrise-sunset.org/json?lat=-XX.XXXXX&lng=XX.XXXXX&formatted=0')
response = urlopen(request)
timestring = response.read()
utcsunrise = timestring[34:39]
utcsunset = timestring[71:76]
utcmorning = timestring[182:187]
utcnight = timestring[231:236]
我正在使用 Sun.py。今天我得到了minutes = 60
,UT = 12.9979740551
孙班:
#10. Return
min = round((UT - int(UT))*60,0)
#add this after min calculate
if min == 60:
hr += 1
min = 0