PERF speciify time index in ModelChain.prepare_inputs

wholmgren · wholmgren · commit 2b83e8a92d5b · 2018-08-12T18:29:38.000-07:00
diff --git a/pvlib/modelchain.py b/pvlib/modelchain.py
@@ -737,7 +737,7 @@ def prepare_inputs(self, times=None, weather=None):
         if weather is not None:
             self.weather = weather
         if self.weather is None:
-            self.weather = pd.DataFrame()
+            self.weather = pd.DataFrame(index=times)
 
         if times is not None:
             self.times = times
