Exploring Data Visually - Data Points: Visualization That Means Something - page 503

FIGURE 4-21 Fitted LOESS curve
CYCLES
A number of factors feed into the economy and affect the unemployment rate,
so there aren't regular intervals in between significant increases. For example,
the data doesn't suggest that unemployment goes up to 10 percent every 10
years. However, there are a lot of things that repeat themselves on regular inter-
vals. Students get summer breaks and people often take summer vacations, and
lunch is typically around noontime, so the restaurant around the corner that
makes burritos bigger than your face usually has a longer line during that hour.
FIGURE 4-22 Weekly cycle