Reshape multiple categorical variables to binary response variables

Question

I am trying to convert the following format:

mydata <- data.frame(movie = c(\"Titanic\", \"Departed\"), 
                     actor1 = c(\"Leo\", \"Jack\"         


        

Answer 1

Since they say variety is the spice of life, here's an approach in base R using table:

table(cbind(mydata[1], 
            actor = unlist(mydata[-1], use.names=FALSE)))
#           actor
# movie      Jack Leo Kate
#   Departed    1   1    0
#   Titanic     0   1    1

The above output is a matrix of class table. To get a data.frame, use as.data.frame.matrix.

as.data.frame.matrix(table(
  cbind(mydata[1], actor = unlist(mydata[-1], use.names=FALSE))))
#          Jack Leo Kate
# Departed    1   1    0
# Titanic     0   1    1