Flow map(Travel Path) Using Lat and Long in R

Question

I am trying to plot flow map (for singapore) . I have Entry(Lat,Long) and Exit (Lat,long). I am trying to map the flow from entry to exit in singapore map.

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Answer 1

Just realized that the original solution usin geom_path was more complicated than necessary. geom_segmentworks without changing the data:

require(ggplot2)
require(ggmap)
basemap <- get_map("Singapore",
                   source = "stamen",
                   maptype = "toner",
                   zoom = 11)

g = ggplot(a)
map = ggmap(basemap, base_layer = g)
map = map + coord_cartesian() +
      geom_curve(size = 1.3,
                 aes(x=as.numeric(Entry_Station_Long),
                     y=as.numeric(Entry_Station_Lat),
                     xend=as.numeric(as.character(Exit_Station_Long)),
                     yend=as.numeric(as.character(Exit_Station_Lat)),
                     color=as.factor(token_id)))
map

This solution leverages Draw curved lines in ggmap, geom_curve not working to implement curved lines on a map.

ggmaps used for simplicity - for more ambitious projects I would recommend leaflet.

Below the solution using a long data format with some prior data wrangling. It also uses straight lines instead of the curves above.

a %>%
  mutate(path = row_number()) -> a

origin = select(a,token_id,Entry_Station_Lat,Entry_Station_Long,path)
origin$type = "origin"
dest = select(a,token_id,Exit_Station_Lat,Exit_Station_Long,path)
dest$type = "dest"

colnames(origin) = c("id","lat","long","path","type")
colnames(dest) = c("id","lat","long","path","type")
complete = rbind(origin,dest)
complete %>% arrange(path,type) -> complete

require(ggmap)
basemap <- get_map("Singapore",
                   source = "stamen",
                   maptype = "toner",
                   zoom = 11)

g = ggplot(complete, aes(x=as.numeric(long),
                         y=as.numeric(lat)))
map = ggmap(basemap, base_layer = g)

map + geom_path(aes(color = as.factor(id)),
                size = 1.1)