Step 5. Modifying Class Properties (optional)

FRAGSTATS includes a Class Properties Editor that allows you to edit the class properties file described under Step 2 and modify the way in which each class is handled in the analysis. Specifically, the Class Properties Editor allows you to change the class name (or character description) and class ID (numerical value) of each class, and designate whether each class should be included in the class output files and/or reclassified as background. The Class Properties Editor is accessed via the Tools menu in the opening window (Fig. 8).

Figure 8. Class properties dialog box.

Note, the Class Properties Editor does not allow you to create a class properties file. Currently, this must be done outside of FRAGSTATS (using any text editor) according to the specifications given previously in Step 2. Here, you can quickly edit the existing file to make temporary changes for the current analysis. The changes remain in effect for the duration of the current FRAGSTATS session, or until you clear the current parameterization scheme or load a new class properties file. This prevents you from having to modify and save a class properties file for every analysis scenario. Note, you cannot edit a class properties file until you have specified one in the Run Parameters dialog box (Step 2).

•    Modifying the Class Name.–You can change a class name (i.e., the character description reported in the patch- and class-level output files) by selecting the desired class (by clicking on the class name in the main text window) and then typing in the new name in the character box next to Name. Note, you cannot use identical class names for different class ID values. Therefore, if you type in a name that already exists, the change will not take effect. In addition, FRAGSTATS automatically sorts class names alphabetically, so the new name may cause the class to shift positions in the list of classes given in the main text window.

•    Modifying the Class ID.–Similarly, you can change a class ID (i.e., integer value associated with a given class name) by selecting the desired class (by clicking on the class name in the main text window), and then typing in the new class ID in the corresponding character box. Note, you cannot use identical class ID’s for different class names. Therefore, if you type in a class ID that already exists, the change will not take effect.

•    Enabling/Disabling Classes.–You can change the enable/disable status of a class by checking or unchecking the Enabled check box. Enabling a class means that it will be analyzed and output in the patch- and class-level output files. Note, this will have no effect if Patch Metrics or Class metrics are not selected in the Run Parameters dialog box. Disabling a class means that the corresponding patch- and class-level metrics will not be output, but it will have no effect on the landscape metrics.

•    Designating Background Classes.–You can reclassify a class to background (i.e., reclassify it to the background value given in the Run Parameters dialog box) by checking the IsBackground check box. Note, you must first specify a background value in the Run Parameters dialog box before you can affect these changes. Designating a class as background will automatically disable it from the output. Moreover, it will have an effect on many metrics (see Overview Section). Note, if a class ID value is the same as the background class value specified in the Run Parameters dialog box, both the Enable and IsBackground check boxes will be inactive. To reactivate these, you must specify a different background value in the Run Parameters dialog box. In addition, designating a class as background in the class properties file can have unintended affects on core area and edge contrast metrics if the full implications are not understood. As noted above, designating a class as background in the class properties editor will result in the reclassification of the corresponding cells to the background value given in the Run Parameters dialog box. To affect changes in how these edges are treated in core area and contrast metrics, you must include the specified background class value in the edge depth and edge contrast weight files, otherwise these edges will be given the default edge depth and contrast weight of zero–possibly an unintended effect.

•    Saving the Class Properties File.–You can save the changes to the class properties file by clicking on the Save As button. This will permanently save the changes made to the file.