R/test_gtfs_freq.R

In gtfs2gps: Converting Transport Data from GTFS Format to GPS-Like Records

#' @title Test whether a GTFS feed is frequency based
#' @description Test whether a GTFS feed is frequency based or whether it
#' presents detailed time table for all routes and trip ids.
#' @param gtfs A GTFS data set stored in memory as a list of data.tables/data.frames.
#' 
#' @return A string "frequency" or "simple".
#' 
test_gtfs_freq <- function(gtfs){
  # Does the GTFS feed has a frequencies.txt file?
  
  # No (it might have an empty frequencies.txt file)
  if(is.null(gtfs$frequencies) == TRUE){ return("simple")
  } else { 
    if(is.null(dim(gtfs$frequencies)[1]) | dim(gtfs$frequencies)[1] == 0){ return("simple") 
    } else if(dim(gtfs$frequencies)[1] > 0) {
      return("frequency")}
  }
}