Graphics Reference
In-Depth Information
column:
VARCHAR
for text and
DOUBLE
for numbers. Append the link data
below the node data and repeat a similar process, beginning with an
edgedef>
tag. Change the name of the
value
column to
weight
so that
Gephi will know to map it to link width. Save it as a file with a GDF
extension, like
interstate-transport-1997.gdf
. The following
snippet shows how to do this:
nodedef>name VARCHAR,state VARCHAR,latitude
DOUBLE,longitude DOUBLE,out
DOUBLE,in DOUBLE,within DOUBLE
AL,Alabama,32.799,-86.8073,0,29048,0
AK,Alaska,61.385,-152.2683,0,4644,0
AZ,Arizona,33.7712,-111.3877,63879,72882,37161
AR,Arkansas,34.9513,-92.3809,0,21455,0
CA,California,36.17,-119.7462,484287,307532,1930
...
edgedef>origin VARCHAR,destination VARCHAR,weight
DOUBLE
CA,AL,2633
CO,AL,277
CT,AL,124
FL,AL,1294
GA,AL,5380
IL,AL,1346
...
Open the new file in Gephi, being sure to flag it as a directed graph. Once
the graph data file is opened, the first step is to arrange the states according
to location. Choose the Geo Layout and, using the default options, click Run
to arrange the nodes geographically. Next, use the Ranking tab to map the
value of incoming shipments to node size, and do the same for links. Make
the nodes large enough to comfortably accommodate labels. Then, using the
label editing pane at the bottom of the graph pane, turn on the two-letter
state code labels, and bind their size to the size of the node.
