Graphics Reference
In-Depth Information
Figure 2-17:
Average flight delays for all routes and airports across the
United States are shown here in red for December 2013, revealing trends
and anomalies.
The link density in
Figure 2-17
is extraordinarily high, but the approach still
works to reveal interesting geospatial patterns of red. It helps that airports
are more likely to link to other airports that are closer by, which reduces the
number of links that cross the entire country.
Although that is the case in many spatial networks, in the 1997 interstate
Commodity Flow Survey data shown in
Figure 2-18
, every state is linked
with almost every other in both directions, creating nearly 2,500
cross-country links. Furthermore, the disparity between state sizes makes
it likely that flow between large states such as California and New Jersey
on opposite sides of the country would obscure the view of small states in
between.
A
link rose
technique was used for the graph in
Figure 2-18
using Aperture
JS, which summarizes outgoing flow in each direction at each node,
removing links for clarity. States are colored by region to distinguish
between near and far flow.
