add tests, fix attribute error

Author: wholmgren

pvlib/test/test_tracking.py

@@ -4,6 +4,7 @@
 import datetime
 
 import numpy as np
+from numpy import nan
 import pandas as pd
 
 from nose.tools import raises, assert_almost_equals
@@ -162,4 +163,106 @@ def test_index_mismatch():
     tracker_data = tracking.singleaxis(apparent_zenith, apparent_azimuth,
                                        axis_tilt=0, axis_azimuth=90,
                                        max_angle=90, backtrack=True, 
-                                       gcr=2.0/7.0)
+                                       gcr=2.0/7.0)
+
+
+def test_SingleAxisTracker_creation():
+    system = tracking.SingleAxisTracker(max_angle=45,
+                                        gcr=.25,
+                                        module='blah',
+                                        inverter='blarg')
+
+    assert system.max_angle == 45
+    assert system.gcr == .25
+    assert system.module == 'blah'
+    assert system.inverter == 'blarg'
+
+
+def test_SingleAxisTracker_tracking():
+    system = tracking.SingleAxisTracker(max_angle=90, axis_tilt=30,
+                                        axis_azimuth=180, gcr=2.0/7.0,
+                                        backtrack=True)
+
+    apparent_zenith = pd.Series([30])
+    apparent_azimuth = pd.Series([135])
+
+    tracker_data = system.singleaxis(apparent_zenith, apparent_azimuth)
+    
+    expect = pd.DataFrame({'aoi': 7.286245, 'surface_azimuth': 37.3427,
+                           'surface_tilt': 35.98741, 'tracker_theta': -20.88121},
+                           index=[0], dtype=np.float64)
+    
+    assert_frame_equal(expect, tracker_data)
+
+
+def test_LocalizedSingleAxisTracker_creation():
+    localized_system = tracking.LocalizedSingleAxisTracker(latitude=32,
+                                                           longitude=-111,
+                                                           module='blah',
+                                                           inverter='blarg')
+
+    assert localized_system.module == 'blah'
+    assert localized_system.inverter == 'blarg'
+    assert localized_system.latitude == 32
+    assert localized_system.longitude == -111
+
+
+def test_SingleAxisTracker_localize():
+    system = tracking.SingleAxisTracker(max_angle=45, gcr=.25,
+                                        module='blah', inverter='blarg')
+
+    localized_system = system.localize(latitude=32, longitude=-111)
+
+    assert localized_system.module == 'blah'
+    assert localized_system.inverter == 'blarg'
+    assert localized_system.latitude == 32
+    assert localized_system.longitude == -111
+
+
+def test_SingleAxisTracker_localize_location():
+    system = tracking.SingleAxisTracker(max_angle=45, gcr=.25,
+                                        module='blah', inverter='blarg')
+    location = Location(latitude=32, longitude=-111)
+    localized_system = system.localize(location=location)
+
+    assert localized_system.module == 'blah'
+    assert localized_system.inverter == 'blarg'
+    assert localized_system.latitude == 32
+    assert localized_system.longitude == -111
+
+
+def test_get_irradiance():
+    system = tracking.SingleAxisTracker(max_angle=90, axis_tilt=30,
+                                        axis_azimuth=180, gcr=2.0/7.0,
+                                        backtrack=True)
+    times = pd.DatetimeIndex(start='20160101 1200-0700',
+                             end='20160101 1800-0700', freq='6H')
+    location = Location(latitude=32, longitude=-111)
+    solar_position = location.get_solarposition(times)
+    irrads = pd.DataFrame({'dni':[900,0], 'ghi':[600,0], 'dhi':[100,0]},
+                          index=times)
+    solar_zenith = solar_position['apparent_zenith']
+    solar_azimuth = solar_position['azimuth']
+    tracker_data = system.singleaxis(solar_zenith, solar_azimuth)
+                          
+    irradiance = system.get_irradiance(irrads['dni'],
+                                       irrads['ghi'],
+                                       irrads['dhi'],
+                                       solar_zenith=solar_zenith,
+                                       solar_azimuth=solar_azimuth,
+                                       surface_tilt=tracker_data['surface_tilt'],
+                                       surface_azimuth=tracker_data['surface_azimuth'])
+    
+    expected = pd.DataFrame(data=np.array(
+        [[ 142.71652464,   87.50125991,   55.21526473,   44.68768982,
+          10.52757492],
+       [          nan,           nan,           nan,           nan,
+                  nan]]),
+                            columns=['poa_global', 'poa_direct',
+                                     'poa_diffuse', 'poa_sky_diffuse',
+                                     'poa_ground_diffuse'],
+                            index=times)
+
+    irradiance = np.round(irradiance, 4)
+    expected = np.round(expected, 4)
+    assert_frame_equal(irradiance, expected)

pvlib/tracking.py

@@ -105,8 +105,16 @@ def get_irradiance(self, dni, ghi, dhi,
 
         surface_tilt = kwargs.pop('surface_tilt', self.surface_tilt)
         surface_azimuth = kwargs.pop('surface_azimuth', self.surface_azimuth)
-        solar_zenith = kwargs.pop('solar_zenith', self.solar_zenith)
-        solar_azimuth = kwargs.pop('solar_azimuth', self.solar_azimuth)
+        
+        try:
+            solar_zenith = kwargs['solar_zenith']
+        except KeyError:
+            solar_zenith = self.solar_zenith
+        
+        try:
+            solar_azimuth = kwargs['solar_azimuth']
+        except KeyError:
+            solar_azimuth = self.solar_azimuth
 
         # not needed for all models, but this is easier
         if dni_extra is None: