#' Formatting multiple columns as numeric
#'
#' Depending on dply's contains()-function.
#' @param string Columnnames containg strings.
#' @param data Dataframe
#' @keywords numeric
#' @export
#' @examples
#' col_num()

col_num<-function(string,data){
## Defining factors for columns containing string (can be vector of multiple strings), based on dplyr

  require(dplyr)
  d<-data
  s<-string
  n<-c()
  
  for(i in 1:length(s)){
  n<-c(n,names(select(d,contains(s[i]))))
  }
  
  for(i in 1:length(n)) {
    d[,n[i]]<-as.numeric(d[,n[i]])
  }
  return(d)
}