Data Smoothing: Polynomial Regression: The Plots Tab :: SAS/IML(R) Studio 3.2: User's Guide

Data Smoothing: Polynomial Regression

The Plots Tab

You can use the Plots tab (Figure 20.4) to create plots that graphically display results of the analysis. The raw residuals are computed as $y - \hat{y}$ , where $\hat{y}$ indicates the variable containing the predicted values of the response.

Creating a plot often adds one or more variables to the data table. The following plots are available:

Observed vs. Explanatory with smoother

creates a scatter plot of the X and Y variables, overlaid with the polynomial smoother.

Confidence limits for means: specifies whether to add 95% upper and lower confidence limits to the Observed vs. Explanatory plot.
Prediction limits for individuals: specifies whether to add 95% upper and lower individual prediction limits to the Observed vs. Explanatory plot.

Observed vs. Predicted

creates a scatter plot of the Y variable versus the predicted values.

Raw residuals vs. Predicted

creates a scatter plot of the residuals versus the predicted values.

Raw residuals vs. Explanatory

creates a scatter plot of the residuals versus the X variable.

Residual normal QQ

creates a normal Q-Q plot of the residuals.

Note: SAS/IML Studio adds a smoother to an existing scatter plot when both of the following conditions are satisfied:

The scatter plot is the active window when you select the analysis.
The scatter plot variables match the analysis variables.

Chapter 18, "Data Smoothing: Loess," discusses how to display multiple smoothers in a single scatter plot, and how to remove smoothers from a scatter plot.

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