Smooth Line Properties

In a chart that displays lines (Line type or X-Y type), you can choose to show curves instead of straight lines. Some options control the properties of those curves.

To access this command...

In the Chart Type dialogue box of a Line chart or X-Y chart that displays lines, choose Stepped in the Lines type drop-down, then click the Properties button.

Press Shift+F1 and point to a control to learn more about that control.

To change line properties

Select Cubic spline or B-spline.

These are mathematical models that influence the display of the curves. The curves are created by joining together segments of polynomials.
Optionally set the resolution. A higher value leads to a smoother line.
For B-spline lines optionally set the degree of the polynomials.