The REG Procedure
- Overview
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Getting Started
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Syntax
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Details
Missing Values Input Data Sets Output Data Sets Interactive Analysis Model-Selection Methods Criteria Used in Model-Selection Methods Limitations in Model-Selection Methods Parameter Estimates and Associated Statistics Predicted and Residual Values Models of Less Than Full Rank Collinearity Diagnostics Model Fit and Diagnostic Statistics Influence Statistics Reweighting Observations in an Analysis Testing for Heteroscedasticity Testing for Lack of Fit Multivariate Tests Autocorrelation in Time Series Data Computations for Ridge Regression and IPC Analysis Construction of Q-Q and P-P Plots Computational Methods Computer Resources in Regression Analysis Displayed Output ODS Table Names ODS Graphics
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Examples
- References
| REFIT Statement |
The REFIT statement causes the current model and corresponding statistics to be recomputed immediately. No output is generated by this statement. The REFIT statement is needed after one or more REWEIGHT statements to cause them to take effect before subsequent PAINT or REWEIGHT statements. This is sometimes necessary when you are using statistical conditions in REWEIGHT statements. For example, consider the following statements:
paint student.>2; plot student.*p.; reweight student.>2; refit; paint student.>2; plot student.*p.;
The second PAINT statement paints any additional observations that meet the condition after deleting observations and refitting the model. The REFIT statement is used because the REWEIGHT statement does not cause the model to be recomputed. In this particular example, the same effect could be achieved by replacing the REFIT statement with a PLOT statement.
Most interactive statements can be used to implicitly refit the model; any plots or statistics produced by these statements reflect changes made to the model and changes made to the data used to compute the model. The two exceptions are the PAINT and REWEIGHT statements, which do not cause the model to be recomputed.