small fixes

Author: birgits

windpowerlib/modelchain.py

@@ -232,7 +232,7 @@ def density_hub(self, weather_df):
         elif self.density_model == 'interpolation_extrapolation':
             logging.debug('Calculating density using linear inter- or '
                           'extrapolation.')
-            density_hub = tools.linear_extra_interpolation(
+            density_hub = tools.linear_interpolation_extrapolation(
                 weather_df['density'], self.wind_turbine.hub_height)
         else:
             raise ValueError("'{0}' is an invalid value. ".format(

windpowerlib/power_output.py

@@ -80,8 +80,8 @@ def power_coefficient_curve(wind_speed, cp_values, rotor_diameter, density,
                                                      density)
     else:
         raise TypeError("'{0}' is an invalid type. ".format(type(
-                        density_correction)) + "`density_corr` must be " +
-                        "Boolean (True or False).")
+                        density_correction)) + "`density_correction` must " +
+                        "be Boolean (True or False).")
 
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
     if isinstance(wind_speed, pd.Series):
@@ -136,8 +136,8 @@ def power_curve(wind_speed, p_values, density=None, density_correction=False):
                                                       density)
     else:
         raise TypeError("'{0}' is an invalid type. ".format(type(
-                        density_correction)) + "`density_corr` must be " +
-                        "Boolean (True or False).")
+                        density_correction)) + "`density_correction` must " +
+                        "be Boolean (True or False).")
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
     if isinstance(wind_speed, pd.Series):
         power_output = pd.Series(data=power_output, index=wind_speed.index,