Available with Spatial Analyst license.

In the Suitability Modeler, use the Transformation pane to convert the values in each criterion to the common suitability scale. Once all the criteria have been appropriately transformed, they can be combined to produce the final suitability map.

## Components

The Transformation pane is divided into three sections. The panel on the left displays a suitability histogram. The center section is used to specify the transformation method. The panel on the right displays a transformation plot. Both panels provide information to assist you with selecting the most appropriate transformation.

### Transformation methods

The center section of the Transformation pane lists the three methods you can use to transform the criteria:

- Unique Categories—A one-to-one transformation to the suitability scale. It is appropriate for categorical data such as land use.
- Range of Classes—Groups ranges of values into classes and assigns each class a suitability value. It is appropriate for continuous values when the same suitability can be assigned to a range of values.
- Continuous Functions—Applies linear and nonlinear functions to transform the input values. It is appropriate for continuous data such as slope, distance from streams, and elevation.

The Continuous Functions method uses the Rescale by Function geoprocessing tool. There are many continuous functions that can be applied. The correct transformation function to use depends on which function best captures the interaction of the phenomenon's preference to the input values. To better understand how the lower and upper thresholds affect the output values, see The interaction of the lower and upper thresholds on the output values.

### Suitability histogram

The suitability histogram provides insight into the distribution of the suitability values in the final suitability map. The histogram and suitability map are updated with each change in the model. The histogram of the final suitability map provides feedback on how changes in the transformation will affect the final output.

### Transformation plot

The transformation plot provides feedback when you're defining the transformation. It depicts how the input values from the criterion will be converted to the suitability scale.

In the plot, the x-axis contains the base criterion input values and the y-axis displays the suitability scale. A histogram of the base criterion values is displayed. If you choose the Continuous Functions method from the center section, the function being applied is overlaid on the histogram. The plot is updated whenever the transformation method in the center section is changed or any of the settings are altered.

## Run the transformation

As each transformation is selected, a raster function chain is created. It is run at screen resolution and the current display extent to dynamically create the resulting transformation and suitability layers.

To run the model at full resolution, click Run on the Suitability tab. The transformations in the raster function chain are calculated at full resolution, producing a more precise suitability map.

The transformed data does not persist unless the transformation layer is saved at full resolution. In the Transformation pane, check the Save transformed dataset when model is run check box. Click the Browse button , then browse to and select the folder where you want to save the transformation layer. Specify the name for the dataset, and click Save. When you click Run when running locally, the transformed dataset is created and saved to disk.