 Regression Results - Function Plots Tab

Regression Models

Select the Function plots tab of the Regression Results dialog box to access options to view various graphs. Different graph options will be available depending on which regression model is selected on the Regression Models for Censored Data dialog box - Quick tab.

The following paragraphs describe the graphs for each of the models. Note that no graphs will be available if this dialog box is displayed via the Proportional Hazard Model with Time-Dependent Covariates dialog box.

Proportional hazard (Cox) regression. When Proportional hazard (Cox) regression is selected as the Model, the following graphs are available:

Graph survival function for means. Click the Graph survival function for means button to produce a graph of the survival function when the values for the independent variables (covariates) are at their respective means.

Graph survival for spec. vals. Click the Graph survival function for spec. vals. button to produce a graph of the survival function based on user specified values of the independent variables (covariates). The Independent Variable Values dialog box will first be displayed in which you specify the values of the independent variables.

Exponential regression. When Exponential regression is selected as the Model, the following graphs are available:

Graph residuals vs. alpha. Click the Graph residuals vs. alpha button to produce a scatterplot of the residual survival times and the standard exponential order statistic. If all points are arranged roughly on a straight line, then the data are consistent with the assumption of exponentiality.

Graph residuals vs. theta. Click the Graph residuals vs. theta button to produce a scatterplot of the residual versus predicted survival times.

Graph residuals vs. log(t). Click the Graph residuals vs. log(t) button to produce a scatterplot of the residual survival times versus the observed log-survival times.

Lognormal regression / Normal regression. When either Lognormal regression or Normal regression is selected as the Model, the following graphs are available:

Graph of observed vs. predicted. Click the Graph of observed vs. predicted button to produce a scatterplot of the observed survival times and the estimated (predicted) survival times.

Graph of predicted vs. residuals. Click the Graph of predicted vs. residual button to produce a scatterplot of the predicted survival times versus the residual survival times.

Normal probability plot of residuals. Click the Normal probability plot of residuals button to produce a normal probability plot of the residual survival times. If the residual survival times (or log-survival times) are normally distributed, all plotted points in this graph should be arranged roughly in a straight line.