lmRob()
function.
cov.lmRob(x)
"lmRob"
.
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efficient regression estimates, mimeo, Universidad de Buenos Aires.
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Robust statistics: the approach based on influence functions.
John & Wiley.
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Robust statistics.
John & Wiley.
Marazzi, A. (1993).
Algorithms, routines, and S functions for robust statistics.
Wadsworth & Brooks/Cole, Pacific Grove, CA.
Maronna, R. A., and Yohai, V. J. (1999). Robust regression with both
continuous and categorical predictors, mimeo, Universidad de Buenos Aires.
stack.df <- data.frame(Loss=stack.loss,stack.x) stack.rob <- lmRob(Loss~Air.Flow+Water.Temp+Acid.Conc.,data=stack.df) stack.cov <- cov.lmRob(stack.robust)