__daylen__(self, year, month, day, lon, lat, altit, upper_limb)

• year,month,date = calendar date, 1801-2099 only. Eastern longitude positive, Western longitude negative Northern latitude positive, Southern latitude negative The longitude value is not critical. Set it to the correct longitude if you're picky, otherwise set to, say, 0.0
• The latitude however IS critical - be sure to get it correct
• altit = the altitude which the Sun should cross Set to -35/60 degrees for rise/set, -6 degrees for civil, -12 degrees for nautical and -18 degrees for astronomical twilight.
• upper_limb: non-zero -> upper limb, zero -> center Set to non-zero (e.g. 1) when computing day length and to zero when computing day+twilight length.

__sunriset__(self, year, month, day, lon, lat, altit, upper_limb)

• year,month,date = calendar date, 1801-2099 only. Eastern longitude positive, Western longitude negative Northern latitude positive, Southern latitude negative The longitude value IS critical in this function!
• altit = the altitude which the Sun should cross Set to -35/60 degrees for rise/set, -6 degrees for civil, -12 degrees for nautical and -18 degrees for astronomical twilight.
• upper_limb: non-zero -> upper limb, zero -> center Set to non-zero (e.g. 1) when computing rise/set times, and to zero when computing start/end of twilight.
• *rise = where to store the rise time
• *set = where to store the set time Both times are relative to the specified altitude, and thus this function can be used to compute various twilight times, as well as rise/set times
• Return value:
• 0 = sun rises/sets this day, times stored at *trise and *tset.
• +1 = sun above the specified 'horizon' 24 hours. *trise set to time when the sun is at south, minus 12 hours while *tset is set to the south time plus 12 hours. 'Day' length = 24 hours
• -1 = sun is below the specified 'horizon' 24 hours 'Day' length = 0 hours, *trise and *tset are both set to the time when the sun is at south.

acosd(self, x)

asind(self, x)

astronomicalTwilight(self, year, month, day, lon, lat)

atan2d(self, y, x)

atand(self, x)

civilTwilight(self, year, month, day, lon, lat)

cosd(self, x)

dayAstronomicalTwilightLength(self, year, month, day, lon, lat)

dayCivilTwilightLength(self, year, month, day, lon, lat)

dayLength(self, year, month, day, lon, lat)

dayNauticalTwilightLength(self, year, month, day, lon, lat)

daysSince2000Jan0(self, y, m, d)

equation_of_time(self, year, month, day, latitude)

Parameters:

year - Year
           (type=int)

month - Month
           (type=int)

day - Day
           (type=int)

latitude - latitude to comput the equation of time
           (type=float)

Returns:

(double fEot, double fR0r, tuple tDeclsc)

• dEot: Correction for the equation of time
• dR0r: Corrected solar constant for the equation of time
• tDeclsc: Declinaison

           (type=tuple)

get_max_solar_flux(self, latitude, year, month, day)

GMST0(self, d)

This function computes GMST0, the Greenwich Mean Sidereal Time at 0h UT (i.e. the sidereal time at the Greenwhich meridian at 0h UT). GMST is then the sidereal time at Greenwich at any time of the day. I've generalized GMST0 as well, and define it as: GMST0 = GMST - UT -- this allows GMST0 to be computed at other times than 0h UT as well. While this sounds somewhat contradictory, it is very practical: instead of computing GMST like:

GMST = (GMST0) + UT * (366.2422/365.2422)

where (GMST0) is the GMST last time UT was 0 hours, one simply computes:

GMST = GMST0 + UT

Julian(self, year, month, day)

nauticalTwilight(self, year, month, day, lon, lat)

rev180(self, x)

revolution(self, x)

This function reduces any angle to within the first revolution by subtracting or adding even multiples of 360.0 until the result is >= 0.0 and < 360.0

sind(self, x)

solar_altitude(self, latitude, year, month, day)

sunpos(self, d)

sunRADec(self, d)

sunRiseSet(self, year, month, day, lon, lat)

tand(self, x)