# Use a Formula to Determine Bar Length

With a categorical attribute on an axis, CODAP plots cases as points stacked in each category. But click on the Configure icon to **Fuse Dots into Bars**.

The bar lengths are proportional to the number of cases in each category.

But sometimes it's useful to compute the bar lengths with a formula. To do so, click on the Configure icon again and set the **scale** to **Formula**.

The bar lengths are now determined by the value of the formula computed for the cases belonging to each category. The formula appears as the label for the numeric axis.

To edit the formula, click where it appears on the numeric axis and choose **Edit Formula**.