By default, the decision graph plots summary values for categories in the first active row field (along the y-axis) against values in the first active column field (along the x-axis). Each graphed category appears as a separate series. 

If only one dimension is selected—for example, by clicking only one TDecisionPivot button—only one series is graphed. 

If you used a decision pivot, you can push its buttons to determine which decision cube fields (dimensions) are graphed. To exchange graph axes, drag the decision pivot dimension buttons from one side of the separator space to the other. If you have a one-dimensional graph with all buttons on one side of the separator space, you can use the Row or Column icon as a drop target for adding buttons to the other side of the separator and making the graph multidimensional. 

If you only want one column and one row to be active at a time, you can set the ControlType property for TDecisionSource to xtRadio. Then, there can be only one active field at a time for each decision cube axis, and the decision pivot's functionality will correspond to the graph's behavior. xtRadioEx works the same as xtRadio, but does not allow the state where all row or all columns dimensions are closed. 

When you have both a decision grid and graph connected to the same TDecisionSource, you'll probably want to set ControlType back to xtCheck to correspond to the more flexible behavior of TDecisionGrid.