Adapt example weather data to multiindex dataframe

Author: Birgit Schachler

example/weather.csv

@@ -1,4 +1,5 @@
-time_index,pressure,temp_air,v_wind,z0,temp_air_2,v_wind_2
+time_index,pressure,temperature,wind_speed,roughness_length,temperature,wind_speed
+,0,2,10,0,10,80
 2010-01-01 00:00:00+01:00,98405.7,267.6,5.32697,0.15,267.57,7.80697
 2010-01-01 01:00:00+01:00,98382.7,267.6,5.46199,0.15,267.55,7.86199
 2010-01-01 02:00:00+01:00,98362.9,267.61,5.67899,0.15,267.54,8.59899