User Help > Displaying Item Data Graphically > Creating a Chart > Distribution Chart: Add Expression or Edit Expression Dialog Box
  
Distribution Chart: Add Expression or Edit Expression Dialog Box
The Add Expression allows you to create an aggregate expression used in a distribution chart. The Edit Expression dialog box allows you to edit such an aggregate expression.
1. In the Aggregation Expression field, create an aggregate expression that incorporates a numeric field in the items returned by the specified query. For example, if your chart currently displays Project items by state, typing: sum("Actual Budget") adds the Budget fields in each state grouping of Project items to display a total budget by state. You can also manually insert fields into your expression by selecting a field from the field list and clicking Insert Field.
Depending on the number of aggregate expressions you create and whether you choose to group field values, only certain graph styles are available. For example, if you do not group field values and you include two aggregate expressions, the XY (scatter) graph style is available. If you do not group field values and you include three aggregate expressions, the bubble style graph is available. For more information on selecting graph styles, see To specify a graph for a chart.
2. In the Expression Label field, type a name for the computed expression label as you want it to display in the chart. For example, if you have an aggregate expression that adds the Budget fields in each state grouping of Project items to display a total budget by state, an appropriate label might be Total Budget. If you do not define a label, the computed expression displays, for example, sum("Actual Budget").
3. In the Display Pattern field, select or type a display pattern for the value of the computed expression.
4. In the Axis Label field, do one of the following:
If your chart contains one aggregate expression, type a name for the numeric axis as you want it to display in the chart.
If you chart contains multiple aggregate expressions and you want to specify the same axis label for all aggregate expressions, type a name for the numeric axis as you want it to display in the chart, or select an existing axis label from list.
If your chart contains multiple aggregate expressions and you want to specify an axis label for each aggregate expression, type a name for the numeric axis as you want it to display in the chart.
5. To add the aggregate expression to the chart, click OK.