# Graph Pad Surface Operations

Creating/Moving/Resizing/Closing a Graph Pad: To create a Graph Pad, select the Graph Pad icon from the tool bar. Then, deposit the icon in the desired location (on either the Interface level or the Map/Model level) by clicking once. When you create a Pad, you'll get a blank page such as the one shown in Figure 6-48. Note that Figure 6-48 shows where to click and/or drag to move, resize and close the Pad. It also identifies the salient features of the default Graph Pad page.

Figure 6-48 Default Graph Pad Page

Pad Icon Operations: As shown in Figure 6-48, associated with the Graph Pad is a Pad icon. The icon exists on the surface of the Interface level or the Map/Model level. When the Pad icon is accessible (either because you have closed the Pad or because you have made the level containing the Pad active), it is amenable to a variety of operations. These are summarized in Figure 6-49.

Figure 6-49 Graph Pad Icon Operations

Operating the Lock: As shown in Figure 6-48, each Graph Pad page contains a small lock in its lower left-hand corner. A click on an open lock will close it. Another click will open the lock. When a Graph Pad page is locked, it will not be overwritten as a simulation unfolds. The lock thus provides a convenient mechanism for retaining the results from a particular simulation run.

Print Button: Also located in the lower left-hand corner of the Graph is a small Print button. Click this button to print out a copy of the entire Graph Pad or specific pages within the Pad.

Dynamite Button: The last icon in the lower left corner of the Graph is the small Dynamite button. Clicking this button will clear the current page of an unlocked Graph Pad.

Pinning and Unpinning: The push-pin icon on the Graph Pad is used to pin the entire pad to the surface of the Interface level or the Map/Model level. Pinned pads will move along with the level to which they are affixed, when you click, drag, scroll, etc., on the level. Unpinned pads will "float," either above or below the level. Click once on the push-pin to pin the pad to the surface. Click again on the push-pin to unpin the pad. Figure 6-50 illustrates a pinned Graph Pad.

Figure 6-50 Pinned Graph Pad

Notes: When a pad is pinned, its title bar and resizing controls disappear. To move or resize, you must first unpin the pad. Because a pinned pad is attached to its level, access to building blocks and objects is retained while the pad is extant.

Unless the entire area of the pad is within the borders of the Interface level or the Map/Model level, the Pin will be grayed out.

Turning Pages: When a Graph Pad contains more than one page, the page-turning apparatus in its lower left corner will become active. The Pad will also tell you what page of the Pad you are on near the lower border. As shown in Figure 6-51, a click on the upper triangle will move you to the next page in the pad. A click on the lower triangle will move you to the previous page.

Figure 6-51 Turning Pages, Navigating to Associated Model Variables, and Activating Logic Tracing

Activating Logic Tracing from Interface Layer Graphs: Model logic tracing is possible for graph pads that have been created on the Interface layer of the software. Select a variable by clicking on its name on the graph surface, and then click the "T" button that appears along the bottom of the page. When you do, you'll be taken to the Map/Model layer, and will be able to sequentially traverse through the inputs to the model variable. When you're done tracing, click the up arrow on the diagram frame to exit Logic tracing. Figure 6-17 shows the look of the Map/Model layer when tracing is in effect.

Helpful Hint: When you turn on "Analyze Mode" in the Run Specs dialog, Logic tracing can be an incredibly powerful tool for model analysis. If you encounter "interesting" model behavior on a graph, you can initiate a tracing sequence. On the Map/Model layer, as you roll the cursor over each model variable you'll see a small graph of its output along with its current value. You'll very quickly be able to diagnose and understand model behavior by traversing its structure.

Navigation to Associated Model Variable: From any graph on any model layer, you can navigate directly to a selected model variable. First, select a variable within the graph by clicking on its name. Then click on the down arrow that appears at the bottom of the graph (next to the Dynamite button). You'll be taken to the associated model variable.

Annotating Graph Pad Pages: It's often useful to annotate a graph. The annotation can help you to refresh your memory when you come back to the graph. In addition, it can help users of your model to better understand what you were thinking as you created the graph. For all graphs except comparative graphs, you can provide text annotation via the "?" button that appears at the bottom of each graph pad page. Click the ?, and type in text in the editable documentation cache. When you're done, simply close the cache. Nothing could be easier.

Annotating Points on a Curve: It is often useful to draw attention to important events, shifts in feedback loop dominance, or other important dynamics by marking notable points on the curve of a time series graph. In order to mark, label, and annotate an important point, first highlight the name of that curve. The annotation point icon will appear among the icons in the lower left of the graph pad. Then, click the annotation point tool to add an annotation point to the graph. Drag the point along the graph to the desired position. Double-clicking any point will open a dialog that allows you to name and annotate that point.

Important note: Adding an annotation to a curve automatically locks the graph. This preserves the integrity of the graph and associated points by preventing a new simulation run from changing the graphed curve. Unlocking the graph will delete the annotations.

Accessing Sensitivity Setups: Whenever you have defined a Graph Pad page as a comparative graph, and have generated output using the software's sensitivity analysis capabilities, the "?" will appear in the lower left of the page. As illustrated in Figure 6-52, a click on the "?" will pop up a journal of the most recent sensitivity setup.

Figure 6-52 Comparative Graph Journaling

Note: To learn more about using sensitivity analysis, see Chapter 3's Run menu documentation.

Other Surface Operations: Using the Paintbrush tool, you can change the color of plots, backgrounds, and Pad icons. Chapter 5 summarizes the use of the Paintbrush in this context. You can clear data, specific variables, scales, and entire pages using the Dynamite tool. Chapter 5 shows how to use the Dynamite on graphs.