def getMoonPhase( n ):
if not isinstance( n, RPNDateTime ):
raise ValueError( '\'moon_phase\' expects a date-time argument' )
datetime = n.to( 'utc' ).format( )
previous = RPNDateTime.convertFromEphemDate( ephem.previous_new_moon( datetime ) ).getLocalTime( )
next = RPNDateTime.convertFromEphemDate( ephem.next_new_moon( datetime ) ).getLocalTime( )
cycle = next - previous
current = n - previous
return current.total_seconds( ) / cycle.total_seconds( )
def getEphemTime( n, func ):
'''Returns a pyephem date-time value from an RPNDateTime value.'''
if not isinstance( n, RPNDateTime ):
raise ValueError( 'expected a date-time argument' )
result = RPNDateTime.convertFromEphemDate( func( n.format( ) ) )
return result.getLocalTime( )
def getAntitransitTime( body, location, date ):
if isinstance( location, str ):
location = getLocation( location )
if not isinstance( body, ephem.Body ) or not isinstance( location, RPNLocation ) or \
not isinstance( date, RPNDateTime ):
raise ValueError( 'expected an astronomical object, a locaton and a date-time' )
location.observer.date = date.to( 'utc' ).format( )
location.observer.horizon = '0'
ephemSetting = location.observer.next_setting( body )
setting = RPNDateTime.convertFromEphemDate( ephemSetting ).getLocalTime( )
rising = RPNDateTime.convertFromEphemDate( location.observer.next_rising( body, start=ephemSetting ) ).getLocalTime( )
return subtract( rising, setting )
def getPreviousSetting( body, location, date ):
if isinstance( location, str ):
location = getLocation( location )
if not isinstance( body, ephem.Body ) or not isinstance( location, RPNLocation ) or not isinstance( date, RPNDateTime ):
raise ValueError( 'expected an astronomical object, a locaton and a date-time' )
old_horizon = location.observer.horizon
location.observer.date = date.to( 'utc' ).format( )
location.observer.horizon = '0'
result = RPNDateTime.convertFromEphemDate( location.observer.previous_setting( body ) ).getLocalTime( )
location.observer.horizon = old_horizon
return result
def getNextDusk( location, date, horizon = -6 ):
if isinstance( location, str ):
location = getLocation( location )
if not isinstance( location, RPNLocation ) or not isinstance( date, RPNDateTime ):
raise ValueError( 'expected locaton and date-time arguments' )
old_horizon = location.observer.horizon
location.observer.date = date.to( 'utc' ).format( )
location.observer.horizon = str( horizon )
result = RPNDateTime.convertFromEphemDate(
location.observer.next_setting( ephem.Sun( ), use_center=True ) ).getLocalTime( )
location.observer.horizon = old_horizon
return result
def getWinterSolstice( n ):
'''Returns the date of the next winter solstice after n.'''
result = RPNDateTime.convertFromEphemDate( ephem.next_solstice( str( n ) + '-07-01' ) )
return result.getLocalTime( )
def getAutumnalEquinox( n ):
'''Returns the date of the next autumnal equinox after n.'''
result = RPNDateTime.convertFromEphemDate( ephem.next_equinox( str( n ) + '-07-01' ) )
return result.getLocalTime( )
def getWinterSolstice( n ):
result = RPNDateTime.convertFromEphemDate( ephem.next_solstice( str( n ) + '-07-01' ) )
return result.getLocalTime( )
def getAutumnalEquinox( n ):
result = RPNDateTime.convertFromEphemDate( ephem.next_equinox( str( n ) + '-07-01' ) )
return result.getLocalTime( )
def getSummerSolstice( n ):
result = RPNDateTime.convertFromEphemDate( ephem.next_solstice( str( n ) ) )
return result.getLocalTime( )
def getVernalEquinox( n ):
result = RPNDateTime.convertFromEphemDate( ephem.next_equinox( str( n ) ) )
return result.getLocalTime( )
