fix klucher spelling

Author: wholmgren

docs/sphinx/source/whatsnew/v0.2.2.txt

@@ -17,6 +17,11 @@ Enhancements
 Bug fixes
 ~~~~~~~~~
 
+* ``irradiance.total_irrad`` had a typo that required the
+  Klucher model to be accessed with ``'klutcher'``. Both spellings will work
+  for the remaining 0.2.* versions of pvlib,
+  but the misspelled method will be removed in 0.3.
+  (:issue:`97`)
 * Fixes an import and KeyError in the IPython notebook tutorials
   (:issue:`94`).
 * Uses the ``logging`` module properly by replacing ``format``

pvlib/irradiance.py

@@ -376,7 +376,7 @@ def total_irrad(surface_tilt, surface_azimuth,
     model = model.lower()
     if model == 'isotropic':
         sky = isotropic(surface_tilt, dhi)
-    elif model == 'klutcher':
+    elif model in ['klucher', 'klutcher']:
         sky = klucher(surface_tilt, surface_azimuth, dhi, ghi,
                       solar_zenith, solar_azimuth)
     elif model == 'haydavies':