Adding Group Charts
Below the Advanced button, on the Data tab of the Chart Expert, is the Group button. It is used to create a chart that shows each group and one of its summary fields. It can only appear within the Report Header/Footer. When you click on the button, the dialog interface changes to reflect grouping specific options. This is shown in Figure 10-5.
Figure 10-5. The grouping options of the Data tab.
The Group button presents a very simple interface when compared to the Advanced button. This is because the Group button is used for creating a simple chart. Whereas the Advanced button allows you to a lot of variations on how many fields are charted on each axis, the Group button only lets you select a single group and a single summary field to chart.
There are two requirements for having the Group button enabled. The first requirement is that there is a group section. Of course, if your report doesn’t have a group section then you certainly can’t chart group values. The second requirement is that the group must use at least one summary field. This is because the group chart only plots summary fields. If you want to create a chart based on a group and your report doesn’t meet these two requirements, then you can choose to place the chart within a Group Header/Footer and set the options using the Advanced button.
The top dropdown box lists the groups on your report. The groups that are listed here change depending upon where you place the chart. No matter how many groups are on your report, only two groups will be listed. These are the top two groups below the location that you are placing the chart. For example, if you place the chart in the Report Header/Footer section, then the first and second outer most groups are listed. However, if you place the chart in the first group’s header/footer, then the next two groups directly below it will be listed in the dropdown box. If there is only one group below where the chart is located, then it will be the only one listed.
When you select the group, the lower dropdown box will show the summary fields for the group selected. From these summary fields, select which field to chart.
