Create dummy variables for non excluding categories in R

Question

I want to create a binary representation of categories. I know how to do it for excluding categories (using caret package) but not an straighforward way to do it for non-excluding categories. For instance

movies <- data.table(movie=c( "batman", "bighero6"), type=list("action",c("action","animation"))) movie type 1: batman action 2: bighero6 action,animation

I would like to obtain something like action animation batman 1 0 bighero6 1 1

Answer 1

我们可以使用dcast

 dcast(movies[,.(type=unlist(type)) ,movie], movie~type, length)