Beginning in the FixedTarget and Observer classes

astroplan/__init__.py

@@ -14,5 +14,5 @@
 if not _ASTROPY_SETUP_:
     from .utils import *
 
-# Import everything in astroplan.core
-from .core import *
+    # Import everything in astroplan.core
+    from .core import *

astroplan/core.py

@@ -2,6 +2,21 @@
 from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
+from astropy.coordinates import (EarthLocation, Latitude, Longitude, SkyCoord,
+                                 AltAz)
+import astropy.units as u
+from astropy.units import Quantity
+
+import pytz
+
+################################################################################
+# TODO: Temporary solution to IERS tables problems
+from astropy.utils.data import download_file
+from astropy.utils import iers
+import datetime
+iers.IERS.iers_table = iers.IERS_A.open(download_file(iers.IERS_A_URL, cache=True))
+################################################################################
+
 #from ..extern import six
 
 #import sys
@@ -25,82 +40,137 @@ class Observer(object):
     Some comments.
     """
 
-    def __init__(self, name, longitude, latitude, elevation, pressure,
-                 relative_humidity, temperature, timezone, description=None):
+    def __init__(self, name=None, location=None, latitude=None, longitude=None,
+                 elevation=None, timezone='UTC', pressure=None,
+                 relative_humidity=None, temperature=None, description=None):
         """
         Initializes an Observer object.
 
-        <longer description>
+        TODO: <longer description>
 
         Parameters
         ----------
         name : str
             A short name for the telescope, observatory or location.
 
-        longitude : str or `~astropy.units.quantity`?
-            The longitude of the observing location.
+        pressure : `~astropy.units.Quantity`
+            The ambient pressure.
 
-        latitude : str or `~astropy.units.quantity`?
-            The latitude of the observing location.
+        location : `~astropy.coordinates.EarthLocation`
+            The location (latitude, longitude, elevation) of the observatory.
+
+        longitude : str or `~astropy.units.Quantity`
+            The longitude of the observing location. If str, should be a string
+            that initializes a `~astropy.coordinates.Longitude` object with
+            units in degrees.
+
+        latitude : str or `~astropy.units.Quantity`
+            The latitude of the observing location. If str, should be a string
+            that initializes a `~astropy.coordinates.Latitude` object with
+            units in degrees.
 
         elevation : `~astropy.units.Quantity`
             The elevation of the observing location, with respect to sea
             level.
 
-        pressure : `~astropy.units.Quantity`
-            The ambient pressure.
-
         relative_humidity : float
             The ambient relative humidity.
 
         temperature : `~astropy.units.Quantity`
             The ambient temperature.
 
-        timezone : WHAT TYPE IS pytz.timezone ?
-            The local timezone.
+        timezone : str or `datetime.tzinfo`
+            The local timezone, as either an instance of `pytz.timezone()` or
+            the string accepted by `pytz.timezone()`.
 
         description : str
             A short description of the telescope, observatory or observing
             location.
         """
-        raise NotImplementedError()
 
-    def set_environment(self, pressure, relative_humidity, temperature):
-        """
-        Updates the Observer object with environmental conditions.
+        if name is not None:
+            self.name = name
 
-        <longer description>
+        if pressure is None:
+            pressure = 0
 
-        Parameters
-        ----------
-        pressure : `~astropy.units.Quantity`
-            The ambient pressure.
+        if temperature is None:
+            temperature = 0 * u.deg_C
 
-        relative_humidity : `~astropy.units.Quantity`
-            The ambient relative humidity.
+        if relative_humidity is None:
+            relative_humidity = 0
 
-        temperature :
-            The ambient temperature.
-        """
-        raise NotImplementedError()
+        self.pressure = pressure
+        self.temperature = temperature
+        self.relative_humidity = relative_humidity
 
-    def get_date(self, input_date_time, timezone=None):
-        """
-        Builds an object containing date and time information.
+        # If lat/long given instead of EarthLocation, convert them
+        # to EarthLocation
+        if location is None and (latitude is not None and longitude is not None):
+            accepted_latlon_types = [str, Quantity]
+            if (type(latitude) in accepted_latlon_types and
+                type(longitude) in accepted_latlon_types):
+                latitude = Latitude(latitude, unit=u.degree)
+                longitude = Longitude(longitude, unit=u.degree)
+
+            self.location = EarthLocation.from_geodetic(longitude, latitude,
+                                                        elevation)
+
+        elif isinstance(location, EarthLocation):
+            self.location = location
 
-        Default time zone is UTC.
-        If time zone (local or otherwise) requested, then uses `datetime.datetime`
-        and pytz.timezone to convert from UTC.
+        else:
+            raise TypeError('Observatory location must be specified with '
+                            'either (1) latitude and longitude in degrees as '
+                            'accepted by astropy.coordinates.Latitude and '
+                            'astropy.coordinates.Latitude, or (2) as an '
+                            'instance of astropy.coordinates.EarthLocation.')
 
-        Must first create date_time object with get_date() before using any other 
-        Observer methods, all of which require one as an argument.
+        # Accept various timezone inputs, default to UTC
+        if isinstance(timezone, datetime.tzinfo):
+            self.timezone = timezone
+        elif isinstance(timezone, str) or isinstance(timezone, unicode):
+            self.timezone = pytz.timezone(timezone)
+        else:
+            raise TypeError('timezone keyword should be a string, or an '
+                            'instance of datetime.tzinfo')
+
+    def altaz(self, time, target=None, obswl=None):
+        """
+        Returns an instance of `~astropy.coordinates.SkyCoord` with altitude and
+        azimuth of the `FixedTarget` called `target` at time `time`.
 
         Parameters
         ----------
-        input_date_time : WHAT TYPE IS astropy.time OBJECT?
+        time : `~astropy.time.Time`
+            Astropy time object.
+
+        target : None (default) or `~astroplan.FixedTarget` or `~astropy.coordinates.SkyCoord`
+            Celestial object of interest. If `target`=None, return just the
+            `~astropy.coordinates.AltAz` frame without coordinates.
 
         """
-        raise NotImplementedError()
+        if obswl is None:
+            obswl = 1*u.micron
+
+        altaz_frame = AltAz(location=self.location, obstime=time,
+                            pressure=self.pressure, obswl=obswl,
+                            temperature=self.temperature,
+                            relative_humidity=self.relative_humidity)
+
+        if target is None:
+            return altaz_frame
+        else:
+            if not (isinstance(target, FixedTarget) or
+                        isinstance(target, SkyCoord)):
+                raise TypeError('The target must be an instance of FixedTarget '
+                                'or SkyCoord.')
+
+            if hasattr(target, 'coord'):
+                coordinate = target.coord
+            else:
+                coordinate = target
+            return coordinate.transform_to(altaz_frame)
 
     # Sun-related methods.
 
@@ -273,7 +343,7 @@ class Target(object):
     """
     __metaclass__ = ABCMeta
 
-    def __init__(self, name, ra, dec, marker=None):
+    def __init__(self, name=None, ra=None, dec=None, marker=None):
         """
         Defines a single observation target.
 
@@ -296,21 +366,40 @@ def ra(self):
         """
         Right ascension.
         """
-        raise NotImplementedError
+        if isinstance(self, FixedTarget):
+            return self.coord.ra
+        raise NotImplementedError()
 
     @property
     def dec(self):
         """
         Declination.
         """
-        raise NotImplementedError
+        if isinstance(self, FixedTarget):
+            return self.coord.dec
+        raise NotImplementedError()
 
 
 class FixedTarget(Target):
     """
     An object that is "fixed" with respect to the celestial sphere.
     """
-
+    def __init__(self, coord, **kwargs):
+        '''
+        TODO: Docstring.
+        '''
+        if not isinstance(coord, SkyCoord):
+            raise TypeError('Coordinate must be a SkyCoord.')
+
+        self.name = kwargs.get('name', None)
+        self.coord = coord
+
+    @classmethod
+    def from_name(cls, query_name, **kwargs):
+        # Allow manual override for name keyword so that the target name can
+        # be different from the query name, otherwise assume name=queryname.
+        name = kwargs.pop('name', query_name)
+        return cls(SkyCoord.from_name(query_name), name=name, **kwargs)
 
 class NonFixedTarget(Target):
     """