Modeling and Multivariate Methods - SAS

Chapter 2 Introduction to the Fit Model Platform 47
Construct Model Effects
3. Select ratio and click Y.
4. Select age and click Add.
5. In the Construct Model Effects box, click age, then select Attributes > Knotted Spline Effect.
6. Specify the number of knots as 5 and click OK.
7. Click Run.
When the report appears:
8. Select Estimates > Custom Test.
Notice that there is only one column. You want three columns.
9. Click the Add Column button twice to produce a total of three columns.
10. Fill in the three knotted columns. See Figure 2.8.
Figure 2.8 Values for the Custom Test for Curvature
11. Click Done.
The report in Figure 2.9 appears. The low Prob > F value indicates that there is indeed curvature to the data.
Figure 2.9 Curvature Report