To create a calculation

Create calculations within expressions using the Expression Editor. Use operators and functions to calculate a new value based on existing property values. Evaluate the results of a calculation with an expression.

Note: For example, use geometric functions to calculate the area for a feature class, then create a subset that has only features with areas above an area value you specify. The Values Pane is not available for use in most calculations.

The Values Pane is only available for use if the Expression Editor is used to create an expression for a single feature class. For help with any expression element, see Creating Expressions - Reference.

To perform a calculation using an operator

  1. Open the Expression Editor based upon the desired use for the expression. See To create an expression for more information.

  2. Directly type a property name in the Expression Area or select a property from the Expression Elements Menu.

  3. Select an operator from the Expression Elements Menu or enter an operator into the Expression Area manually:

  4. Select or enter the value to evaluate.

  5. Specify any further conditions for the expression. Note: To create a complex property evaluation, insert an AND or OR operator, and then insert another operator/property combination. For example, to find every building whose street address is greater than 100 but less than 200, use the expression: Building_Street_Address > 100 AND Building_Street_Address < 200.

  6. Click OK to apply the expression.

To perform a calculation using a function

  1. Open the Expression Editor.

  2. Select a function from the Expression Elements Menu or enter a function into the Expression Area manually:

  3. Select the property to apply the function to.

    Note: For example, to round the height of buildings down to the nearest lower whole number and then find buildings whose rounded height is less than 8 feet, use the expression: Floor(ROOF_HEIGHT) < 8.

  4. Click OK to apply the expression.

To find area or length (geometric function)

  1. Open the Expression Editor.

  2. In the expression area, enter or insert the geometric function (Area2D or Length2D).

  3. Insert the Geometry property in parentheses after the function.

    Note: Insert the Geometry property from the Properties category in the Expression Elements Menu . Do not change it manually or substitute a value for this property.

  4. Specify further conditions for the expression. For example, to create a subset of your Buildings data that specifies only buildings with an area above 10,000 square feet, use the expression: Area2D(GEOMETRY) > 10000.

  5. Click OK to finish the expression.

Parent page: Use Expressions