changed variable time interval calculation in hsu model and test

pvlib · wholmgren · Aug 28, 2020 · May 20, 2020 · Jun 9, 2020 · Jun 9, 2020
commit f88827611bc13183d25775fe271bb2c88baa1789
diff --git a/pvlib/soiling.py b/pvlib/soiling.py
@@ -77,12 +77,12 @@ def hsu(rainfall, cleaning_threshold, tilt, pm2_5, pm10,
    cleaning_times = accum_rain.index[accum_rain >= cleaning_threshold]

    # determine the time intervals in seconds (dt_sec)
-    dt = rainfall.index.values       # datetimes in nanoseconds
-    dt2 = np.roll(dt.copy(), 1)       # shift array values by one place
+    dt = rainfall.index
+    dt2 = np.roll(dt.copy(),1)
    # subtract shifted values from original and convert to seconds
-    dt3 = np.delete((dt-dt2)/1e9, 0)
+    dt3 = np.delete((dt-dt2),0).total_seconds()
    # append last value to end so same number of elements in the array
-    dt_sec = np.append(dt3, dt3[-1]).astype('float64')
+    dt_sec = np.append(dt3[0], dt3).astype('float64')

    horiz_mass_rate = (
        pm2_5 * depo_veloc['2_5'] + np.maximum(pm10 - pm2_5, 0.)

diff --git a/pvlib/tests/test_soiling.py b/pvlib/tests/test_soiling.py
@@ -63,10 +63,10 @@ def expected_output_3():
    dt_new = dt + pd.to_timedelta(timedelta, 'm')
    expected_output_3 = pd.Series(
        data=[0.96576705, 0.9387675, 0.91437615, 0.89186852, 1.,
-              1., 0.95185738, 0.9387675, 1., 1.,
-              1., 1., 0.96576705, 0.92630786, 0.90291005,
-              0.88122293, 0.86104089, 1., 1., 1.,
-              0.96576705, 0.9387675, 0.91437615, 0.89186852],
+                1., 0.98093819, 0.9387675, 1., 1.,
+                1., 1., 0.96576705, 0.9387675 , 0.90291005,
+                0.88122293, 0.86104089, 1., 1., 1.,
+                0.96576705, 0.9387675, 0.91437615, 0.89186852],
        index=dt_new)
    return expected_output_3