Usage of logarithmic interpolation/extrapolation to modelchain

Author: SabineHaas

windpowerlib/modelchain.py

@@ -23,7 +23,8 @@ class ModelChain(object):
     wind_speed_model : string
         Parameter to define which model to use to calculate the wind speed at
         hub height. Valid options are 'logarithmic', 'hellman' and
-        'interpolation_extrapolation'. Default: 'logarithmic'.
+        'interpolation_extrapolation', 'log_interpolation_extrapolation'.
+        Default: 'logarithmic'.
     temperature_model : string
         Parameter to define which model to use to calculate the temperature of
         air at hub height. Valid options are 'linear_gradient' and
@@ -55,7 +56,8 @@ class ModelChain(object):
     wind_speed_model : string
         Parameter to define which model to use to calculate the wind speed at
         hub height. Valid options are 'logarithmic', 'hellman' and
-        'interpolation_extrapolation'. Default: 'logarithmic'.
+        'interpolation_extrapolation', 'log_interpolation_extrapolation'.
+        Default: 'logarithmic'.
     temperature_model : string
         Parameter to define which model to use to calculate the temperature of
         air at hub height. Valid options are 'linear_gradient' and
@@ -300,6 +302,11 @@ def wind_speed_hub(self, weather_df):
                           'extrapolation.')
             wind_speed_hub = tools.linear_interpolation_extrapolation(
                 weather_df['wind_speed'], self.wind_turbine.hub_height)
+        elif self.wind_speed_model == 'log_interpolation_extrapolation':
+            logging.debug('Calculating wind speed using logarithmic inter- or '
+                          'extrapolation.')
+            wind_speed_hub = tools.logarithmic_interpolation_extrapolation(
+                weather_df['wind_speed'], self.wind_turbine.hub_height)
         else:
             raise ValueError("'{0}' is an invalid value. ".format(
                 self.wind_speed_model) + "`wind_speed_model` must be "