strsplit by row and distribute results by column in data.frame

Question

So I have the data.frame

dat = data.frame(x = c(\'Sir Lancelot the Brave\', \'King Arthur\',  
                       \'The Black Knight\', \'The Rabbit\'), stri         


        

Answer 1

Using data.table as it appears you are trying to use it.

library(data.table)
DT <- data.table(dat)
DTB <- DT[, list(y = unlist(strsplit(x, ' '))), by = x]

new <- rep(NA_character_,  DTB[,.N,by =x][which.max(N), N])
names(new) <- paste0('V', seq_along(new))
DTB[,{.new <- new 
      .new[seq_len(.N)] <- y 
       as.list(.new)} ,by= x]

Or using reshape2 dcast to reshape

library(reshape2)

dcast(DTB[,list(id = seq_len(.N),y),by= x ], x ~id, value.var = 'y')