Use expressions to specify a subset of features. Use subsets to compare data within a feature class.
An expression is a way to specify conditions. You can filter feature classes in the Model Explorer using an expression, which creates a subset of the feature class based on the conditions you specified. See Use Expressions to learn more about expressions.
For example, to visually compare buildings of different roof heights, create a subset for each height and assign a different highlight color to each one. Then turn the highlighting on and off for the different subsets to compare their number, location, and so on.
A single feature class can have multiple subsets.
Two subsets, highlighted in different colors, showing buildings of different heights
Once you define subsets, you can do the following:
- Highlight subsets independently from their feature class or from each other. For example, create a subset of roads whose material is big cobblestones, and another whose material is paving stones. You can highlight all roads, cobblestone roads, and paving-stone roads independently. You can also specify a different highlight color for each subset, so you can tell which features are which.
- Filter the subset further, making a subset of the subset.
- Select all the members of the subset, or specify an expression that selects a subset of the subset (without creating a new subset).
- View the properties of the subset features in the Data Table.
- Rename, redefine, copy, or remove the subset.
You can also use the Source Filter option while bringing data in. This makes the feature class in your model a subset of the original data source.