As a HeNCE program runs it generates trace events. These events can be used to drive an animation of the HeNCE program either during or after its execution.
To view a program trace enter trace mode of htool by selecting the Load Trace File option under the Trace pull-down menu. The graph and cost matrix with which the program was run will be displayed.
The row of buttons just above the graph are used to control the playback of the trace animation. The first button is the rewind button. It rewinds the trace file to its beginning. The second button is the reverse step button. It causes the graph to single-step backwards in time. The third button is the stop button. It can be used to stop playback of the tracefile. The fourth button is used for single stepping forward through the tracefile. The fifth button is the play button, used to continuously play back the tracefile.
To the lower left of the graph is a slider. This slider determines the speed of the trace playback. At the center, the trace will be played back in approximately real time. The top setting is 100 times faster, and the bottom setting is 100 times slower.
During the trace, nodes in the program graph and the machines in the cost matrix are highlighted to indicate their state. The histogram at the lower right of the window also displays the state of each machine over time. The scrollbars on the histogram can be used to display different parts of the histogram; vertical to see different machines, and horizontal to scroll through time. The up and down arrows in the histogram are buttons that change the time scale. During tracing and execution, a red hairline indicates the current time.