A parameter file is a document containing all the data that the model needs to perform a simulation. It is in the XML data format and is written in plain text. Parameter files have a .xml extension.
A parameter file is as long as it needs to be, depending on how you want to set up your run. At the least, the parameter file must specify the length of the run (see Run Setup), describe the plot, define the tree species and their attributes, list the behaviors in the order in which they will run, and provide whatever data the behaviors need.
In addition, parameter files can contain very detailed initial conditions in the form of maps of tree and grid data. This data is normally produced in detailed output files. For more on how to add this data to a parameter file, see Adding to a parameter file.
Many of those who used the old version of SORTIE probably got used to editing their parameter files directly using a spreadsheet program. In fact, sometimes you had to because there were parameters that could not be edited in the old interface. The new model interface is designed to give you all the tools you need to create and modify your parameter files. You are welcome to view and modify the new parameter files directly, if you wish. They can be opened in any text editor. Be warned, however, that with the new data format, this is an extremely daunting task and you will never actually need to do it.
For detailed instructions on creating a new parameter file from scratch, see the Creating a parameter file topic. To edit existing parameter files, you can use the different choices in the Edit menu (Tree Setup to set up the basics of the tree population, Grid Layer Setup to configure grids, Model flow to specify the behaviors to use and in what order, Parameters to provide parameter values, and Output options to set up reporting.
In order to run, a parameter file must be complete and all data in it valid. As you edit a parameter file, the part that you are editing will be validated as part of the edit process. It is certainly possible, however, to be working with a parameter file that has a problem of some sort, especially if you started with an existing parameter file instead of from scratch. The file will be validated before you run it, but if you want to do a double-check beforehand, you can either save it from the File menu or view all its parameters in the Parameters window and then click OK. These methods may not catch every problem, but they will catch most of them.
The parameter file is in the XML data format and is not easily readable by humans. The model can make you tab-delimited text versions of your data that you can open in any text editor or spreadsheet program. Unfortunately, there is currently no support for outputting all data at once. If your parameter file contains both parameters and maps, you must convert them separately.
To save your parameter values, use the Edit->Parameters window. To save grid map values, use the Edit->Grid layer setup window. Files you save in this way are for your reference only. They cannot be used as input.