John Hendrickx
2005-Mar-31 22:16 UTC
[R] [R-pkgs] perturb package for evaluating collinearity
I've uploaded the R package "perturb" to CRAN. Perturb contains two programs for evaluating collinearity. "Colldiag" calculates condition indexes and variance decomposition proportions to detect and track down collinear sets of variables. "Perturb" takes a different approach. It re-estimates the model a specified number of times, adding random noise ("perturbations") to selected variables at each iteration. Categorical variables are randomly reclassified. A summary then displays the impact of these perturbations on the stability of the coefficients. Perturb is not limited to linear regression and can handle interaction effects and transformations of independent variables. Version 1 of perturb was available from my website. This new version makes it much easier to reclassify categorical variables. In addition, colldiag now has a "fuzz" option to suppress printing of small variance decomposition values. Comments and criticisms invited, John Hendrickx _______________________________________________ R-packages mailing list R-packages at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-packages