Plotting yields over time
Now that the units have been dealt with, it's time to explore the datasets. An obvious question to ask about each crop is, "how do the yields change over time in each US state?" Let's draw a line plot to find out!
ggplot2 is loaded, and corn and wheat datasets are available with metric units.
Это упражнение является частью курса
Introduction to Writing Functions in R
Интерактивное практическое упражнение
Попробуйте выполнить это упражнение, дополнив этот пример кода.
# Using corn, plot yield (kg/ha) vs. year
___(___, ___(___, ___)) +
# Add a line layer, grouped by state
___(___(___ = ___)) +
# Add a smooth trend layer
___()