The applet has two mouse modes: Build Network and Edit Travel
In Build Network mode, the mouse can be used to build a
To do this,
you specify arcs in the network by a pair of mouse clicks.
The first mouse click must be on an existing node in the network.
The second mouse click can be anywhere on the drawing canvas.
If it is on an existing node, then an arc is created connecting the two
selected nodes. By default, the direction of the arc is from the first node to
the second node. To reverse the direction, simply hold the shift
key while making the second click.
If the second mouse click is not on any existing node, then a new node is
automatically created at the clicked location and an arc is created as
The applet always initializes the network with one preexisting node, which
is labeled a. We refer to this node as the root node. It
is where we are going.
By forcing you to build the network arc by arc always using an existing node
for the first click, we guarantee that the network will be connected.
Randomly Generating Problems
As an alternative to generating problems by hand, you can click on
Generate Random Problem in either of the above two mouse modes
to quickly produce a random network with random travel times.
The textfield labeled Nodes can be editted to specify
the number of nodes in the network.
If the Seed field is left blank
then an internally generated seed value will be used and the behavior of the
random problem generator will be different every time the applet is run.
however, a seed value is given (it must be an integer), then that value is
used to seed the random number generator.
Specifying a value for the number of
nodes and for the seed uniquely determines the sequence of problems
for the original class project desription (Java version).
Finally, click here
for the Java Applet version of the same tool.