add dirint tests

Author: wholmgren

pvlib/test/test_clearsky.py

@@ -76,4 +76,44 @@ def test_disc_value():
     disc_data = clearsky.disc(ghi, zenith, times, pressure=pressure)
     assert_almost_equal(disc_data['DNI_gen_DISC'].values,
                         np.array([830.46, 676.09]), 1)
-    
+
+def test_dirint():
+    clearsky_data = clearsky.ineichen(times, tus, linke_turbidity=3)
+    pressure = 93193.
+    dirint_data = clearsky.dirint(clearsky_data['GHI'], ephem_data['zenith'], 
+                                  ephem_data.index, pressure=pressure)
+
+def test_dirint_value():
+    times = pd.DatetimeIndex(['2014-06-24T12-0700','2014-06-24T18-0700'])
+    ghi = pd.Series([1038.62, 254.53], index=times)
+    zenith = pd.Series([10.567, 72.469], index=times)
+    pressure = 93193.
+    dirint_data = clearsky.dirint(ghi, zenith, times, pressure=pressure)
+    assert_almost_equal(dirint_data.values,
+                        np.array([928.85, 688.26]), 1)
+
+def test_dirint_tdew():
+    times = pd.DatetimeIndex(['2014-06-24T12-0700','2014-06-24T18-0700'])
+    ghi = pd.Series([1038.62, 254.53], index=times)
+    zenith = pd.Series([10.567, 72.469], index=times)
+    pressure = 93193.
+    dirint_data = clearsky.dirint(ghi, zenith, times, pressure=pressure,
+                                  temp_dew=10)
+    assert_almost_equal(dirint_data.values,
+                        np.array([934.06, 640.67]), 1)
+
+def test_dirint_no_delta_kt():
+    times = pd.DatetimeIndex(['2014-06-24T12-0700','2014-06-24T18-0700'])
+    ghi = pd.Series([1038.62, 254.53], index=times)
+    zenith = pd.Series([10.567, 72.469], index=times)
+    pressure = 93193.
+    dirint_data = clearsky.dirint(ghi, zenith, times, pressure=pressure,
+                                  use_delta_kt_prime=False)
+    assert_almost_equal(dirint_data.values,
+                        np.array([901.56, 674.87]), 1)
+
+def test_dirint_coeffs():
+    coeffs = clearsky._get_dirint_coeffs()
+    assert coeffs[0,0,0,0] == 0.385230
+    assert coeffs[0,1,2,1] == 0.229970
+    assert coeffs[3,2,6,3] == 1.032260