Basic Analysis and Graphing - SAS

230 Performing Simple Logistic Regression Chapter 7
Additional Examples of Logistic Regression
Figure 7.8 Examples of Sample Data Table and Logistic Plot Showing an Almost Perfect y by x
Relationship
Example of ROC Curves
To demonstrate ROC curves, proceed as follows:
1. Open the Penicillin.jmp sample data table.
2. Select Analyze > Fit Y by X.
3. Select Response and click Y, Response.
4. Select In(Dose) and click X, Factor.
Notice that JMP automatically fills in Count for Freq. Count was previously assigned the role of Freq.
5. Click OK.
6. From the red triangle menu, select ROC Curve.
7. Select Cured as the positive.
8. Click OK.
Note: This example shows a ROC Curve for a nominal response. For details about ordinal ROC curves, see
the Recursive Partitioning chapter in the Modeling and Multivariate Methods book.
The results for the response by In(Dose) example are shown here. The ROC curve plots the probabilities
described above, for predicting response. Note that in the ROC Table, the row with the highest
Sens-(1-Spec) is marked with an asterisk.