From Function, select the function of the Graph variables. For example, if you select Maximum, Minitab defines the color gradient for the heatmap based on the maximum value of the Graph variables in each rectangle. If you enter a text column in Graph variables, you can only select Percent equal to specified values, Number of Nonmissing values, or Number of Missing values.

Some options require you to enter additional values.

- Percentile
- If you select Percentile, you must enter a value in Percentile value. The value must be between 0 and 100. Minitab uses the value you enter to define the color gradient in the heatmap. For example, if you enter 50, Minitab uses the 50th percentile to define the color gradient for each rectangle of the heatmap.
- Percent between two values
- If you select Percent between two values, you must enter numeric values in First value and Second value. The value you enter for First value must be less than or equal to the value you enter for Second value. Minitab defines the color gradient for the heatmap based on the percentage of observations that is between the two values.
- Percent equal to specified values
- If you select Percent equal to specified values, you must enter one or more values in Values. The values must be the same type of data as the column you entered in Graph variables. Minitab defines the color gradient for the heatmap based on the percentage of observations that is equal to the values that you enter.