R/compress-1-compress_to_list_f.R

In junyitt/tfunction: tfunction for Trading Purposes

#' compress_to_list_f function
#' 
#' compress data.frame to list (able to compress size of rda file by >50%!)
#' 
#'
#' Return list
#' 
#' @param df
#' @keywords compress df to list
#' @export
#' @examples
#' compress_to_list_f(fdf)
compress_to_list_f <- function(df){
      
      x <- colnames(df)
      u1 <- grepl(pattern = "[Cc]ode", x)
      codevar <- x[u1][1]
      list1 <- lapply(unique(df[,codevar]), FUN = function(j){
            u1 <- df[,codevar] == j
            return( df[u1,] )
      
      })
      
      return(list1)
      
}