R/order_dewey.R

In shug0131/cctu: In-house Functions for Report Writing at Cambridge Clinical Trials Unit

#'sorts inputs that look like Dewey decimal numbering
#'@param x a vector of character strings
#'
#'@return  a numeric vector that sorts the input as per dewey decimal system, without confusing 10.2, vs 10.10
#'@export



order_dewey=function(x){

  if(!inherits(x,"character")){stop("Must input a character vector")}
#split up the string into a list of vectors broken by decimals
  X=strsplit(x,"\\.")
  check_non_numeric <- sapply(X, function(x){any(grepl("\\D",x))})
  if( any(check_non_numeric)){stop("non numeric values are not allowed")}
# FInd out the longest length
  nrow=max(sapply(X,length))
#Pad the empty elements out and return a matrix
  X=sapply(X, function(x){c(as.integer(x), rep(NA,nrow-length(x)))  })
# a trick to get X technically as a list of columns, and then allow
# order() over an arbitrary number of columns as arguments to break ties
  if(nrow>1){
    X <- as.data.frame(t(X))
  } else{
    X <- as.data.frame(X)
  }
  do.call(order,X)
}