Run Panel

The Run Panel is used to control the execution of a Pablo data analysis
graph.  This panel can be left up during the entire execution of a graph
to provide the level of control desired.

The Run button simply starts the data analysis graph executing, or
resumes execution if had begun but was stopped.

The Stop button stops the execution of a graph, even if all input
records have not been processed.

The Checkpoint button will, in the future, support the checkpointing
of a particular data analysis graph state for later resumption.

The Snapshot button invokes the Pablo Snapshot Utility.  This utility is
capable of capturing the state of individual widgets or entire display
FU's within Pablo.  Capability for interacting with the Utility must be
built into each display FU.  (Currently, this has only been done for the
ScatterPlotMatrix).

The three "Execute Graph" radio buttons at the upper left of the panel
control the function of the Run button.  The default, Continuously, means
that Pablo will continue executing the graph until the Stop button is
selected or execution completes.  In continuous mode, the
"Number of graph steps" option specifies the frequency with which Pablo
will internally process X events.  Via this option one can give priority
to either data processing or graphics updates.  This is particularly
important when one wants to synchronize the displays with sonic output;
in this case, the number of graph steps is best set to one.

The "N times" radio button means that the analysis graph will be
executed the specified number of times when the Run button is selected.
After this number of graph executions, Pablo will halt execution and
await further user input.

The "Module by module" option causes the Run button to execute a single
module in the graph.  This breaks down the "N times" option into smaller
pieces so the impact of a single module's execution can be observed.

