### Jürgen Kampf ### Stochastics III ### Introduction in Vectors and Data Frames ### Part 2: Solution x$Year[x$Day.Temperature>20] # Explanation: x$Day.Temperature # returns the vectors of the Day Temperatures. So the Boolean vector x$Day.Temperature>20 # is TRUE at those positions, where the day temperature is larger than 20. # The solution extracts from the vector x$Year # only those elements for which x$Day.Temperature>20 # is TRUE, in other words only those elements, for which the day temperature # is larger than 20.