Import column names from step wise regression in R

问题

I want to import the variables selected from the step-wise regression process as column names so that I have the "Output" has the variables from the step-wise regression as shown below. But, my code below does NOT do that.

I cannot understand what I am doing wrong here. Can somebody help me please?

iris$area <- iris$Petal.Length * iris$Petal.Width
iris <- data.table(iris)
mydata <- iris[Species %in% "virginica", list(Sepal.Length,Sepal.Width,Petal.Length,Petal.Width,area)]

fit <- lm(area~., data=mydata)
satis.step <- step(fit, direction="both")
datanew <- iris[Species %in% "virginica", list(Species, paste(attr(satis.step$formula, "term.labels"),collapse = ", ")) ]

Output

I need the output to look like:

Species       Sepal.Length     Sepal.Width
------------------------------------------
virginicia         6.3            3.3
virginicia         5.8            2.7

回答1:

I got this.

selvars=c("Species", attr(satis.step$terms, "term.labels"))
datanew <- iris[Species %in% "virginica", ..selvars ]

> datanew
      Species Sepal.Length Petal.Length Petal.Width
 1: virginica          6.3          6.0         2.5
 2: virginica          5.8          5.1         1.9
 3: virginica          7.1          5.9         2.1

来源：https://stackoverflow.com/questions/46576491/import-column-names-from-step-wise-regression-in-r