Example of assigning a secondary scale
main topic     see also      

Suppose you have created an overlaid scatterplot displaying the relationships between two different y-axis variables and a common x-axis variable. Although you know the correlation of both pairs is very high, the resulting graph does not reflect this. Because the individual ranges of the y-axis variables are so different, adding a secondary scale may remedy the deceptive appearance.

Step 1: Create the graph

1    Open the worksheet BEARS.MTW.

2    Choose Graph > Scatterplot.

3    Click Simple, and then click OK.

4    In row 1, under Y, enter Length and under X, enter Weight.

5    In row 2, under Y, enter Head.L and under X, enter Weight.

6    Click Multiple Graphs and click the Multiple Variables tab.

7    Under Show Graphs of Different Variables, choose Overlaid on the same page, and click OK in each dialog box.

Graph window output

Step 2: Assign a secondary scale

1    Double-click the y-axis.

2    Click the Secondary tab.

3    Under Scale for Length, select Primary from the drop-down list.

4    Under Scale for Head.L, select Secondary from the drop-down list. Click OK.

Graph window output