Visualizing Spatial Relationships - Data Points: Visualization That Means Something - page 297

Instead of hard-coding the values 6.9, 8.7, and 10.8 in your code, you can
replace those values with q1 , q2 , and q3 , respectively. The advantage of cal-
culating the values programmatically is that you can reuse the code with a
different dataset just by changing the CSV file.
Which color scale you choose depends on that data you have and what
message you want to convey. For this particular dataset, I prefer the lin-
ear scale because it represents the distribution better and highlights the
relatively high unemployment rates across the country. Working from Fig-
ure 8-18, you can add a legend, a title, and a lead-in paragraph for a more
finalized graphic, as shown in Figure 8-20.
FIGurE 8-20 Finished map with title, lead-in, and legend