Contents:
- Introduction
- The Viewer's components
- Selecting a graph
- Setting the graph's detail
- Making and viewing annotations
- Saving graphs
The SimJava Graph Viewer is a utility built to accompany the SimJava simulation package. SimJava simulations may be set to produce graphical output in the form of .sjg files. These files may be opened by the utility to display graphs for all the measures calculated.
Note: The plot displayed corresponds to the sample average at each point in time, not the obtained observations.
The measure's graph is presented in the center. In the upper left corner the user is presented with the entities and their measures as defined in the simulation. In the case of an output analysis method having been used, this area also contains the options referring to the information displayed in the adjacent area. This area, in the upper right section, contains either the general run information or the total measurements obtained for the measure currently on display. The lower left section contains the graph's controls. These manage the graph's zoom as well as the information that is displayed. This information ranges from displaying the graph's annotations, to displaying a particular replication.
The graph displayed corresponds to a particular entity and measure. As mentioned previously, the upper left section contains the list of entities and measures. The available entities are those for which measures were defined in the simulation. Upon selecting an entity from the list, the graph is automatically updated to display the first defined measure. Furthermore, the full list of measures that were defined for the selected entity is made available to the user. Selecting another entity leads to a similar update of the graph.
In the case that independent replications were used as an output analysis method or variance reduction technique, additional graphs are available for each entity's measure. These graphs correspond to the progress of the measure's sample average in each replication. The total number of replications can be obtained from the panel displaying the general run information. The desired replication may then be selected by the corresponding control in the lower left section.
In any case, the detail level that was selected via the graph controls is applied to the new graph.
As mentioned previously, the controls in the lower left section set the level of detail and the information displayed by the graph. The controls available vary depending on the output analysis method used in the simulation.
The first control is the zoom level. The viewer's graphs may be zoomed on the basis of time or on the basis of the measure's values. Two input fields are present to enable the user to select the appropriate zoom level for the time (X-axis) and the values (Y-axis). The selected zoom level is applied by clicking the zoom button.
A series of checkboxes follows that represent additional information that may be viewed. The first option is to display only the steady state period. In this case, the sample average plot presented corresponds only to the observations obtained in steady state. The second option corresponds to displaying or not the transient period. The third option displays the total mean obtained for the measure. In the case of an output analysis method having been used, the total mean's confidence interval is also presented.
At this point, additional options are present depending on the type of output analysis used. In the case of batch means, the option to view the batches and their means is provided. Alternatively, when independent replications have been used, the user is provided with the ability to view the measure's progress in any replication. Furthermore, the option to view all the replications is available, in which case the plots from all replications are presented in one graph using different colors. If this option is selected the area containing sample measurements is used to present a legend of the replications. Certain options are unavailable when viewing this combined graph such as viewing the transient time or a graph's annotations.
A final option available in any case of output analysis is to turn the annotations on or off. If selected, this option displays all the annotations that have been made for the currently selected graph.
An additional option that is available is to view sample measurements up to a certain point in time. To achieve this, the user left clicks on the graph at the desired point in time. The panel displaying sample measurements is updated to display the measurements obtained up to the selected time. To clear the graph of the current selection, the user clicks outside the graph's bounds. By default, the sample measurements displayed cover the entire simulation run.
Making and viewing annotations
The SimJava Graph Viewer provides the user with the ability to make and view annotations. Such functionality is particularly useful when commenting on a graph is necessary. In order to make an annotation the user right clicks at a certain point of interest on the graph. A dialogue is subsequently presented in which the user provides the annotation's text.
To view existing annotations, the user selects the corresponding option from the controls. Once the annotations are presented, the user can left click on one in order to view and/or update its text.
Graphs may be stored for later inspection. To be precise, what is accomplished when saving a graph is actually to store the annotations made. This is the case since the graph data itself may not be altered. A graph is saved through the relevant options available in the "File" menu.
An option that is also available in the "File" menu is to save the current graph as an image. Using this option, a graph may be stored as a GIF image in order to be placed in documents or published online. The image will display all the information currently selected by the user.