addDistanceToSubway.R

for (i in 1:nrow(air)){
  distance <- 999
  lat_air <- air[i,"Latitude"]
  long_air <- air[i,"Longitude"]

  for(j in 1:nrow(subway)){
    dist <- earth.dist(long_air,lat_air,subway[j,"Longitude"],subway[j,"Latitude"])
    if(dist < distance){
      distance <- dist
    }
  }
  print(i)
  flush.console()
  air[i,"distSubway"] <- distance
}