break AIRMASS_MODELS into *_ZENITH_MODELS

wholmgren · wholmgren · commit 28ed81268c76 · 2016-01-31T12:47:44.000-07:00
diff --git a/pvlib/atmosphere.py b/pvlib/atmosphere.py
@@ -11,10 +11,11 @@
 
 import numpy as np
 
-AIRMASS_MODELS = ['kastenyoung1989', 'kasten1966', 'simple', 
-                  'pickering2002', 'youngirvine1967', 'young1994',
-                  'gueymard1993']
-                  
+APPARENT_ZENITH_MODELS = ('simple', 'kasten1966', 'kastenyoung1989',
+                          'gueymard1993', 'pickering2002')
+TRUE_ZENITH_MODELS = ('youngirvine1967', 'young1994')
+AIRMASS_MODELS = APPARENT_ZENITH_MODELS + TRUE_ZENITH_MODELS
+
 
 def pres2alt(pressure):
     '''
