Well, I figured it out.
I just have to pass the object as argument.
lambda.fmla <- as.formula(object=back.m)
and then change the matrix with the lambda.
質問
I'm using the function step
to perform a backward selection.
library(MASS)
full.m <- lm(fmla, data=mean.mydata)
back.m <- step(full.m, direction = "backward", trace = 1)
This method is then used to calculate a data transformation,
# Best transformation
bc <- boxcox(back.m)
lambda <- bc$x[which.max(bc$y)]
Now I would like to create the new formula with lambda and the selected variables,
lambda.fmla <- as.formula(paste("I(mass^lambda) ~ ", paste(variables, collapse= "+")))
Any ideas? I've looked in the back.m
object but so far I could not find out.
解決
Well, I figured it out.
I just have to pass the object as argument.
lambda.fmla <- as.formula(object=back.m)
and then change the matrix with the lambda.