R/getReachMovements_internal.R

In Myfanwy/fishtrackr: A set of functions for analyzing and summarizing acoustic telemetry data

# getReachOneFish; called by getReachMovements

getReachOneFish = function(x)
{
  x = x[order(x$arrival),]
  # difference between departure 1...n-1 and arrival 2...n
  ttime = as.numeric(x$arrival[-1]) - as.numeric(x$departure[-nrow(x)])
  between_stns = x$Station[-nrow(x)] != x$Station[-1]
  data.frame(depStation = x$Station[-nrow(x)][between_stns],
             arrStation = x$Station[-1][between_stns],
             reachname = paste(x$Station[-nrow(x)][between_stns], x$Station[-1][between_stns], sep = "-" ),
             reachdistance = x$Rkm[-nrow(x)][between_stns] - x$Rkm[-1][between_stns],
             ttime = ttime[between_stns]/ (60*60*24),
             TagID = x$TagID[1],
             stringsAsFactors = FALSE)
}