optional astropy

test pandas and xarray time conversion

remove pypy from travis since travis pypy3 is old

.travis.yml

@@ -8,7 +8,6 @@ git:
 python:
 - 3.6
 - 3.5
-- pypy3
 
 os:
 - linux

README.md

@@ -27,7 +27,8 @@ Includes some relevant
 ## Prerequisites
 
 * Python ≥ 3.5 or PyPy3
-* [AstroPy](http://www.astropy.org/) (optional, used for ECI coordinates)
+
+References to AstroPy are optional, algorithms from Vallado and Meeus are used if AstroPy is not present.
 
 
 ## Install
@@ -39,7 +40,7 @@ pip install pymap3d
 or for the latest development code:
 ```sh
 git clone https://github.com/scivision/pymap3d
-
+cd pymap3d
 pip install -e .
 ```
 

pymap3d/aer.py

@@ -78,7 +78,8 @@ def aer2geodetic(az: float, el: float, srange: float,
 
 def eci2aer(eci: Tuple[float, float, float],
             lat0: float, lon0: float, h0: float,
-            t: datetime) -> Tuple[float, float, float]:
+            t: datetime,
+            useastropy: bool=True) -> Tuple[float, float, float]:
     """
     Observer => Point
 
@@ -95,14 +96,15 @@ def eci2aer(eci: Tuple[float, float, float],
     azimuth, elevation (degrees/radians)                             [0,360),[0,90]
     slant range [meters]                                             [0,Infinity)
     """
-    ecef = np.atleast_2d(eci2ecef(eci, t))
+    ecef = np.atleast_2d(eci2ecef(eci, t, useastropy))
 
     return ecef2aer(ecef[:, 0], ecef[:, 1], ecef[:, 2], lat0, lon0, h0)
 
 
 def aer2eci(az: float, el: float, srange: float,
             lat0: float, lon0: float, h0: float, t: datetime,
-            ell=None, deg: bool=True) -> np.ndarray:
+            ell=None, deg: bool=True,
+            useastropy: bool=True) -> np.ndarray:
     """
 
     input
@@ -120,7 +122,7 @@ def aer2eci(az: float, el: float, srange: float,
     """
     x, y, z = aer2ecef(az, el, srange, lat0, lon0, h0, ell, deg)
 
-    return ecef2eci(np.column_stack((x, y, z)), t)
+    return ecef2eci(np.column_stack((x, y, z)), t, useastropy)
 
 
 def aer2ecef(az: float, el: float, srange: float,

pymap3d/azelradec.py

@@ -5,6 +5,7 @@
 from datetime import datetime
 import numpy as np
 from .vallado import azel2radec as vazel2radec, radec2azel as vradec2azel
+from .timeconv import str2dt  # astropy can't handle xarray times (yet)
 try:
     from astropy.time import Time
     from astropy import units as u
@@ -36,7 +37,7 @@ def azel2radec(az_deg: float, el_deg: float,
 
     obs = EarthLocation(lat=lat_deg * u.deg, lon=lon_deg * u.deg)
 
-    direc = AltAz(location=obs, obstime=Time(time),
+    direc = AltAz(location=obs, obstime=Time(str2dt(time)),
                   az=az_deg * u.deg, alt=el_deg * u.deg)
 
     sky = SkyCoord(direc.transform_to(ICRS()))
@@ -77,6 +78,6 @@ def radec2azel(ra_deg: float, dec_deg: float,
                       Angle(dec, unit=u.deg),
                       equinox='J2000.0')
 
-    altaz = points.transform_to(AltAz(location=obs, obstime=Time(time)))
+    altaz = points.transform_to(AltAz(location=obs, obstime=Time(str2dt(time))))
 
     return altaz.az.degree, altaz.alt.degree

pymap3d/ecef.py

@@ -236,7 +236,8 @@ def uvw2enu(u: float, v: float, w: float,
     return East, North, Up
 
 
-def eci2geodetic(eci: np.ndarray, t: datetime) -> Tuple[float, float, float]:
+def eci2geodetic(eci: np.ndarray, t: datetime,
+                 useastropy: bool=True) -> Tuple[float, float, float]:
     """
     convert ECI to geodetic coordinates
 
@@ -257,7 +258,7 @@ def eci2geodetic(eci: np.ndarray, t: datetime) -> Tuple[float, float, float]:
 
     eci2geodetic() a.k.a. eci2lla()
     """
-    ecef = np.atleast_2d(eci2ecef(eci, t))
+    ecef = np.atleast_2d(eci2ecef(eci, t, useastropy))
 
     return np.asarray(ecef2geodetic(ecef[:, 0], ecef[:, 1], ecef[:, 2])).squeeze()
 

pymap3d/eci.py

@@ -1,13 +1,15 @@
 from datetime import datetime
 import numpy as np
+from .datetime2hourangle import datetime2sidereal
 try:
     from astropy.time import Time
 except ImportError as e:
     Time = None
 
 
 def eci2ecef(eci: np.ndarray,
-             time: datetime) -> np.ndarray:
+             time: datetime,
+             useastropy: bool=True) -> np.ndarray:
     """
      Observer => Point
 
@@ -20,10 +22,13 @@ def eci2ecef(eci: np.ndarray,
     ------
     x,y,z  [meters] target ECEF location                             [0,Infinity)
     """
-    if Time is None:
-        raise ImportError('eci2ecef requires Numpy and AstroPy')
+    useastropy = useastropy and Time
+
+    if useastropy:
+        gst = Time(time).sidereal_time('apparent', 'greenwich').radian
+    else:
+        gst = datetime2sidereal(time, 0.)
 
-    gst = Time(time).sidereal_time('apparent', 'greenwich').radian
     gst = np.atleast_1d(gst)
     assert gst.ndim == 1 and isinstance(gst[0], float)  # must be in radians!
 
@@ -43,7 +48,8 @@ def eci2ecef(eci: np.ndarray,
 
 
 def ecef2eci(ecef: np.ndarray,
-             time: datetime) -> np.ndarray:
+             time: datetime,
+             useastropy: bool=True) -> np.ndarray:
     """
     Point => Point
 
@@ -57,10 +63,13 @@ def ecef2eci(ecef: np.ndarray,
     ------
     eci  x,y,z (meters)
     """
-    if Time is None:
-        raise ImportError('ecef2eci requires AstroPy')
+    useastropy = useastropy and Time
+
+    if useastropy:
+        gst = Time(time).sidereal_time('apparent', 'greenwich').radian
+    else:
+        gst = datetime2sidereal(time, 0.)
 
-    gst = Time(time).sidereal_time('apparent', 'greenwich').radian
     gst = np.atleast_1d(gst)
     assert gst.ndim == 1 and isinstance(gst[0], float)  # must be in radians!
 

pymap3d/timeconv.py

@@ -14,7 +14,8 @@ def str2dt(time: datetime) -> np.ndarray:
         return time
     elif isinstance(time, str):
         return parse(time)
-    elif isinstance(time[0], str):
-        return [parse(t) for t in time]
-    else:
-        return time.values.astype('datetime64[us]').astype(datetime)
+    else:  # some sort of iterable
+        try:
+            return [parse(t) for t in time]
+        except TypeError:
+            return time.values.astype('datetime64[us]').astype(datetime)

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = pymap3d
-version = 1.7.9
+version = 1.7.10
 author = Michael Hirsch, Ph.D.
 author_email = [email protected]
 description = pure Python coordinate conversions, following convention of several popular Matlab routines.

tests/test_astropy.py

@@ -39,7 +39,7 @@ def test_anglesep_meeus():
     assert pmh.anglesep_meeus(35, 23, 84, 20) == approx(ha)
 
 
-def test_eci():
+def test_eci_astropy():
     pytest.importorskip('astropy')
 
     t = '2013-01-15T12:00:05'
@@ -60,7 +60,7 @@ def test_eci():
         pm.aer2eci(aer1[0], aer1[1], -1, 42, -100, 0, t)
 
 
-def test_eci_times():
+def test_eci_times_astropy():
     pytest.importorskip('astropy')
 
     with pytest.raises(AssertionError):
@@ -73,5 +73,36 @@ def test_eci_times():
     assert pm.ecef2eci(pm.eci2ecef(eci0s, [t0] * 2), [t0] * 2) == approx(eci0s)
 
 
+def test_eci_vallado():
+    t = '2013-01-15T12:00:05'
+    lla = pm.eci2geodetic(eci0, t, useastropy=False)
+    assert lla == approx(lla0, rel=0.2)
+
+    eci1 = pm.eci2ecef(eci0, t, useastropy=False)
+    assert eci1 == approx([649012.04640917, -4697980.55129606, 4250818.82815207], rel=0.001)
+
+    assert pm.ecef2eci(eci1, t, useastropy=False) == approx(eci0, rel=0.001)
+
+    aer1 = pm.eci2aer(eci0, 42, -100, 0, t, useastropy=False)
+    assert aer1 == approx([83.73050, -6.614478, 1.473510e6], rel=0.001)
+
+    assert pm.aer2eci(*aer1, 42, -100, 0, t, useastropy=False) == approx(eci0, rel=0.001)
+
+    with pytest.raises(ValueError):
+        pm.aer2eci(aer1[0], aer1[1], -1, 42, -100, 0, t, useastropy=False)
+
+
+def test_eci_times_vallado():
+    with pytest.raises(AssertionError):
+        pm.eci2ecef(eci0, [t0, t0], useastropy=False)
+
+    with pytest.raises(AssertionError):
+        pm.ecef2eci(eci0, [t0, t0], useastropy=False)
+
+    eci0s = np.stack((eci0, eci0))
+    assert pm.ecef2eci(pm.eci2ecef(eci0s, [t0] * 2, useastropy=False),
+                       [t0] * 2, useastropy=False) == approx(eci0s, rel=0.001)
+
+
 if __name__ == '__main__':
     pytest.main(['-xrsv', __file__])

tests/test_main.py

@@ -6,10 +6,8 @@
 """
 import pytest
 from pytest import approx
-from datetime import datetime
 import numpy as np
 import pymap3d as pm
-from pymap3d.timeconv import str2dt
 
 pi = np.pi
 nan = np.nan
@@ -46,15 +44,6 @@ def test_ellipsoid():
     assert pm.ecef2geodetic(*xyz0, ell=pm.Ellipsoid('moon')) == approx([41.808706, -82., 4.630807e6])
 
 
-def test_str2dt():
-
-    assert str2dt(datetime(2014, 4, 6, 8)) == datetime(2014, 4, 6, 8)  # passthrough
-    assert str2dt('2014-04-06T08:00:00') == datetime(2014, 4, 6, 8)
-    ti = [str2dt('2014-04-06T08:00:00'), str2dt('2014-04-06T08:01:02')]
-    to = [datetime(2014, 4, 6, 8), datetime(2014, 4, 6, 8, 1, 2)]
-    assert ti == to   # even though ti is numpy array of datetime and to is list of datetime
-
-
 def test_losint():
 
     pytest.importorskip('pytest', minversion='3.5')

tests/test_time.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+import pytest
+from pymap3d.timeconv import str2dt
+from datetime import datetime
+
+t0 = datetime(2014, 4, 6, 8)
+
+
+def test_str2dt():
+    assert str2dt(t0) == t0  # passthrough
+    assert str2dt('2014-04-06T08:00:00') == t0
+    ti = [str2dt('2014-04-06T08:00:00'), str2dt('2014-04-06T08:01:02')]
+    to = [t0, datetime(2014, 4, 6, 8, 1, 2)]
+    assert ti == to   # even though ti is numpy array of datetime and to is list of datetime
+
+
+def test_xarray_time():
+    xarray = pytest.importorskip('xarray')
+
+    t = {'time': t0}
+
+    ds = xarray.Dataset(t)
+    assert str2dt(ds['time']) == t0
+
+
+def test_pandas_time():
+    pandas = pytest.importorskip('pandas')
+
+    t = pandas.Series(t0)
+    assert str2dt(t) == t0
+
+
+if __name__ == '__main__':
+    pytest.main([__file__])