When you
create a network graph with a fixed position layout pattern, you must
specify the positions file for the graph. A positions
file is a SAS data set that meets the following requirements:
-
The data set contains the following
variables:
-
a variable containing
the X coordinates for the nodes
-
a variable containing
the Y coordinates for the nodes
The data set can contain additional
variables, but must have at least these two.
-
The data must be in the same order
as the data in the node data set. The reason is that the positions
data set doesn't require a "node" variable for its orientation; it
relies on the position of the nodes in the node data set.
Tip
One easy way
to create a positions data set is simply to add two variables (for
the X and Y coordinates) to the node data set.
Here is
an example of a small data set:
When you
create a network graph using the positions file, you are prompted
to specify which variables correspond to the X and Y axes.
SAS/GRAPH
Network Visualization Workshop then graphs the nodes and their links
based on your network data and the values provided for the X and Y
axes.
