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.
Cet exercice fait partie du cours
Introduction to Writing Functions in R
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Using corn, plot yield (kg/ha) vs. year
___(___, ___(___, ___)) +
# Add a line layer, grouped by state
___(___(___ = ___)) +
# Add a smooth trend layer
___()