Using the compute function

Compute creates a field containing the results of an equation or expression involving the attributes in a layer. You can build equations using the calculator or you can create more complex expressions with the Advanced Compute features and EASI scripts. For more information about EASI scripts, see the EASI User Guide.

When you build an expression, either type the expression in the Expression box or build the expression by clicking the buttons and items in the window. Combining the two methods may cause unwanted effects.

  1. From the Field menu in the Attribute Manager, click Compute.
  2. From the View menu in the Compute window, click one of the following options:
    • Basic: creates an equation using the attributes and the calculator
    • Advanced: creates an expression using the attributes, the calculator, and functions
  3. Build an expression. You can use any combination of the following to create the expression that you want:
    • Type all or part of the expression in the Expression box. Text should be placed in double quotes (for example, 'text').
    • Double-click an attribute in the Attributes list to add it to the expression.
    • Use the calculator to include integers and the basic mathematic operators in the expression.
    • Select a category of functions from the Categories list box to display the available functions in that category. In the Functions list, select the function that you want to use in the expression. (Available only on the Advanced Compute)
  4. If you want to display the result on the screen without adding it to the Attribute Manager, enable the Single Value check box and proceed to step 8.
  5. If you want to include the result in the Attribute Manager, select a field in the Field Name box that will receive the results of the computation or type the name of a new field.
  6. In the Field Description box, type a description of the contents of the field.
  7. Choose one of the following types of field from the Field Type list:
    • Text: defines the field as a text string
    • Integer: defines the field for positive or negative whole numbers
    • Float: defines the field for single-precision real numbers
    • Double: defines the field for double-precision real numbers
  8. Click the Run button. If you want to save the equation with the layer, click Save.
Parent topic: Working with the Attribute Manager
Previous topic: Selecting all records that match a value in the current cell
Next topic: Opening the Aggregate Attributes window

© PCI Geomatics Enterprises, Inc.®, 2026. All rights reserved.