improve melt by keeping factors

R/melt.R

@@ -114,8 +114,14 @@ fd_melt <- function(x, key, id = NULL, keep = NULL){
 #' @export
 #'
 fd_melt_STICK = function(x, key1, keep){
+  if(is.factor(x[[keep]])){
+    vec = factor(do.call("c", lapply(1:nrow(x),
+                                     function(i){ as.character(rep(x[[keep]][i], length(x[[key1]][[i]])))})),
+                 levels = levels(x[[keep]]))
+  } else{
     vec = do.call("c", lapply(1:nrow(x),
                               function(i){ rep(x[[keep]][i], length(x[[key1]][[i]]))}))
+  }
   return(vec)
 }