Use number expressions to specify values in many places in Infrastructure Studio. You can generate a new numerical value based on existing values. You can also include a number expression within a text expression by placing it within parentheses. For example, you might create a text expression that specifies a state name and population for a label. To express the population in millions, you can apply a number expression that divides the population value by 1,000,000.
For example, you might create a text and number expression that specifies the following label text:
concat (State_Name, concat (': ', (Population/1000000)))
Where <State_Name> and <Population> are the values of these properties for each feature. The label would display California: 33.
The Number Expression dialog box has two modes: Builder and Advanced. In Builder mode you can only create expressions that use valid syntax. In Advanced mode you can create expressions using any syntax, even if it is not handled by the Builder. You cannot move from Advanced mode to Builder mode unless conditions are valid. Further, an expression with valid syntax is not allowed in the builder if it contains functions or property names that are not in the layer’s data source.
Spaces are ignored in Advanced mode except within the single quotes that specify a constant.
To build a number expression
- In the Number Expression dialog box, under Property Or Constant, do either of the following:
- Click Property and select a property from the list.
- Click Constant and enter the value to use.
- Click New to add additional elements to the expression.
- Under Operation, click a arithmetic operator.
- Under Property Or Constant, specify a property or constant value.
- To group and ungroup conditions, select the conditions and click Group Selected Conditions or Ungroup Selected Conditions as needed.
- Click OK.
- Click File menu
Save.