DOT Flow Charts

The Account Explorer provides a structured way to look at account details. Even so, it can be a challenge to get an overview of how the accounts connect together link together for even moderately complex models. This is where the DOT flow charts come in to play. The flow charts provide a graphical view of account structure, showing how all attributes and accounts are linked together. If a picture is worth a thousand words, these flow charts tell a pretty good story.

We have shown examples of flow charts in the preceeding sections. In fact, most of the flow chart figures in this chapter have been created with the DOT flow charting tool. The charts are simple polygon and arrow charts, showing the inputs and outputs to the accounts in the model.

Account flow charts are created by selecting the "Generate DOT flow chart" option under the File menu in the Account Explorer. This menu item will present a dialog (see Figure 50, “The account flow chart dialog”) requesting the name of the output file as well as several other paramters. When the "Finish" button is pressed, the Account Explorer will generate a file containing flow charting commands in the DOT language. The ".dot" file can be processed using the GrapViz [6] visualization software to produce flow charts in a variety of file formats (e.g. PNG, PS, SVG) that can be used on the web or as high quality figures in reports.

Figure 50. The account flow chart dialog

Use the Account flow chart dialog to specify the name of the output file and other parameters. Selecting the Simplify option will omit trivial accounts that have the same name as the input attribute. The ".dot" file will be generated when the Finish button is pressed.


Once the ".dot" file has been generated, it will need to be processed by the GraphViz "dot" program in order to produce the flow chart. Assuming the the output file in the previous step was named "accounts.dot", then the required GraphViz command to create a PNG image would be

dot -Tpng -o accounts.png accounts.dot

These instructions are automatically included within the dot file for your reference. You can read the contents of this plain file using a simple text editor such as Notepad. See the documentation on the GraphViz website for more information on paramaters and options for the "dot" program.

After processing the ".dot" file with the above command, the resulting graphic will look like the following figure.

Figure 51. Account flow chart for the C5_Full sample model

An example of the type of output generated from the ".dot" file and the GraphViz visualization software. This example shows the simplified output of the accounts in the Crowsnest C5_Full sample model. We present it here for completeness and as a demonstration of how these attributes and accounts are linked. If you wished to examine this graphic more closely, you could either print (plot) the output on large paper or pan around within a graphics package or web browser.


In the next few paragraphs we will look at pieces of this flow chart more closely, and describe some of the conventions that are represented by the symbols that are used.

Figure 52. Flow chart of yield and route accounts

The product.Yield.managed.Decid attribute feeds into the Mill.Decid exclusive account and, depending on the selected destination, eventually into the route accounts. It also supplies values to the product.Yield.managed.Decid summary account to track total yield coming from the deciduous component of stands.


Figure 53. Flow chart of harvest patch accounts

The values from the product.disturbed attribute flow into the harvest patch accounts. The patch.harvest account is the master account for all the related patch size accounts. The values from this attribute will determine the contribution to patch size, and the resulting patch will be allocated into one of the user-defined classes. Further patch sub-targets are automatically defined to enable target setting and reporting on patch shape, area, and frequency.

Similarily (but not show here), the feature.Visual.disturb feeds into the patch.disturbance.young account, and from there into various patch size class accounts and sub-accounts.


Figure 54. Flow chart of VQO group accounts

In this example group accounts are used to summarize the feature.Visual.disturb attribute by Visual Quality Objective zone.




[6] The GraphViz software is not distributed with Patchworks, but is available free of charge from AT&T Research at www.graphviz.org. The web site includes downloads for Windows, Mac and Linux systems. You will need to download and install GraphViz in order to convert DOT file output into figures.