rsquared.lmRob(x)
"lmRob".
The robust R-squared is only computed for S-estimates and MM-estimates.
If the object
x is an alternate M-S estimate or robust efficient
weighted least squares,
NULL is returned.
stack.df <- data.frame(Loss=stack.loss,stack.x)
stack.rob <- lmRob(Loss~Air.Flow+Water.Temp+Acid.Conc.,data=stack.df,
robust.control=lmRob.robust.control(final.alg="MM"))
rsquared.lmRob(stack.robust)