How to use pyephem - 9 common examples

def __init__(self, ra, dec, f_c=.012, name='', **kwargs):
        """ra:           source's right ascension (epoch=2000)
        dec:          source's declination (epoch=2000)
        f_c:          the plasma frequency (a measure of the electron density)
                      in the direction of the source, which can cause the 
                      source to appear displaced from its quiescent position 
                      as a function of frequency."""
        RadioBody.__init__(self, name=name)
        ephem.FixedBody.__init__(self)
        self._ra, self._dec, self.f_c = ra, dec, f_c
    def compute(self, observer, refract=False):

def compute(self, observer, refract=False):
        if self.in_cache(observer, refract): return
        ephem.FixedBody.compute(self, observer)
        self.map = self.gen_uvw_map(observer, refract=refract)
        self.cache(observer, refract)

d_d = (d_Z*(-sin_Z*sin_lat + cos_Z*cos_lat*cos_A) \
                - d_A*sin_Z*cos_lat*sin_A) / cos_d
        # Convert zenith angle displacement into hour-angle component
        d_H = (d_d*sin_H*sin_d - d_A*cos_A*sin_Z - d_Z*sin_A*cos_Z) \
                / (cos_H*cos_d)
        return H + d_H, d + d_d
        

#  ____           _ _       _____ _              _ ____            _       
# |  _ \ __ _  __| (_) ___ |  ___(_)_  _____  __| | __ )  ___   __| |_   _ 
# | |_) / _` |/ _` | |/ _ \| |_  | \ \/ / _ \/ _` |  _ \ / _ \ / _` | | | |
# |  _ < (_| | (_| | | (_) |  _| | |>  <  __/ (_| | |_) | (_) | (_| | |_| |
# |_| \_\__,_|\__,_|_|\___/|_|   |_/_/\_\___|\__,_|____/ \___/ \__,_|\__, |
#                                                                    |___/ 

class RadioFixedBody(ephem.FixedBody, RadioBody):
    """A class combining ephem's FixedBody with a RadioBody."""
    def __init__(self, ra, dec, f_c=.012, name='', **kwargs):
        """ra:           source's right ascension (epoch=2000)
        dec:          source's declination (epoch=2000)
        f_c:          the plasma frequency (a measure of the electron density)
                      in the direction of the source, which can cause the 
                      source to appear displaced from its quiescent position 
                      as a function of frequency."""
        RadioBody.__init__(self, name=name)
        ephem.FixedBody.__init__(self)
        self._ra, self._dec, self.f_c = ra, dec, f_c
    def compute(self, observer, refract=False):
        if self.in_cache(observer, refract): return
        ephem.FixedBody.compute(self, observer)
        self.map = self.gen_uvw_map(observer, refract=refract)
        self.cache(observer, refract)

def juldate2ephem(num):
    """Convert Julian date to an ephem date, which is measured from noon,
    Jan. 1, 1900."""
    return ephem.date(num - 2415020)

def set_ephemtime(self, t=None):
        """Set the current time to a time derived from the ephem package."""
        if t is None: t = ephem.now()
        self.date = t
        self.epoch = t
        self.cache += 1
    def src_eq_vec(self, body):

__radd__ = __add__
    def __neg__(self):
        return -self.pos
    def __sub__(self, a):
        return self.pos - a.pos
    def __rsub__(self, a):
        return a.pos - self.pos

#     _                         _                    _   _             
#    / \   _ __ _ __ __ _ _   _| |    ___   ___ __ _| |_(_) ___  _ __  
#   / _ \ | '__| '__/ _` | | | | |   / _ \ / __/ _` | __| |/ _ \| '_ \ 
#  / ___ \| |  | | | (_| | |_| | |__| (_) | (_| (_| | |_| | (_) | | | |
# /_/   \_\_|  |_|  \__,_|\__, |_____\___/ \___\__,_|\__|_|\___/|_| |_|
#                         |___/                                        

class ArrayLocation(ephem.Observer):
    """Collected information about where and when an array is."""
    def __init__(self, location=None, uv=None):
        """location:   location of the array in (lat, long, [elev])
        uv:         Miriad UV file"""
        ephem.Observer.__init__(self)
        self.cache = 0
        if not uv is None: self.from_uv(uv)
        else:
            if location is None:
                raise ValueError('Must provide either uv or location.')
            self.update_location(location)
    def update_location(self, location):
        """Initialize the antenna array for the provided location.  Locations
        may be (lat, long) or (lat, long, elev)."""
        if len(location) == 2: self.lat, self.long = location
        else: self.lat, self.long, self.elev = location

def __init__(self, location=None, uv=None):
        """location:   location of the array in (lat, long, [elev])
        uv:         Miriad UV file"""
        ephem.Observer.__init__(self)
        self.cache = 0
        if not uv is None: self.from_uv(uv)
        else:
            if location is None:
                raise ValueError('Must provide either uv or location.')
            self.update_location(location)
    def update_location(self, location):

def set_jultime(self, t=None):
        """Set the current time to a Julian date."""
        if t is None: t = ephem.julian_date()
        self.set_ephemtime(juldate2ephem(t))
    def set_ephemtime(self, t=None):

def response(self, azalt, pol='x'):
        """Return the total antenna response to a source at azalt=(az, alt),
        including beam response, per-frequency gain, and a phase offset."""
        zang = ephem.separation(self.pointing, azalt)
        beam_resp = self.beam.response(zang, azalt[0], pol=pol)
        return beam_resp * self.gain