trek: Grab a trek from Google

In dkahle/ggmap: Spatial Visualization with ggplot2

Grab a trek from Google

Description

Sequence treks (latitude-longitude sequences following ordinary paths, e.g. roads) between two locations using the Google Directions API. Note: To use Google's Directions API, you must first enable the API in the Google Cloud Platform Console. See register_google().

Usage

trek(
  from,
  to,
  mode = c("driving", "walking", "bicycling", "transit"),
  output = c("simple", "all"),
  alternatives = FALSE,
  units = "metric",
  urlonly = FALSE,
  override_limit = FALSE,
  ext = "com",
  inject = "",
  ...
)

Arguments

from	name of origin addresses in a data frame
to	name of destination addresses in a data frame
mode	driving, bicycling, walking, or transit
output	amount of output ("simple" or "all")
alternatives	should more than one route be provided?
units	"metric"
urlonly	return only the url?
override_limit	override the current query count
ext	domain extension (e.g. "com", "co.nz")
inject	character string to add to the url
...	...

Value

a tibble

Author(s)

David Kahle [e-mail] with the key decoding algorithm due to Stack Overflow user akhmed

See Also

https://developers.google.com/maps/documentation/directions/, https://stackoverflow.com/questions/30270011/ggmap-route-finding-doesnt-stay-on-roads/, route(), routeQueryCheck(), register_google()

Examples

## Not run:  requires Google API key, see ?register_google

## basic usage
########################################

from <- "houston, texas"
to <- "waco, texas"

(route_df <- route(from, to, structure = "route"))
(trek_df  <-  trek(from, to, structure = "route"))

qmap("college station, texas", zoom = 8) +
  geom_path(
    aes(x = lon, y = lat),  colour = "red",
    size = 1.5, alpha = .5,
    data = route_df, lineend = "round"
  ) +
  geom_path(
    aes(x = lon, y = lat),  colour = "blue",
    size = 1.5, alpha = .5,
    data = trek_df, lineend = "round"
  )



from <- "rice university houston texas"
to <- "1001 Bissonnet St, Houston, TX 77005"
trek_df <- trek(from, to)
qmplot(lon, lat, data = trek_df, geom = "path", maptype = "terrain",
  color = I("red"), size = I(2), alpha = I(.5)
)

trek_df <- trek(from, to, mode = "walking")
qmplot(lon, lat, data = trek_df, geom = "path", maptype = "terrain",
  color = I("red"), size = I(2), alpha = I(.5)
)

trek_df <- trek(from, to, mode = "transit")
qmplot(lon, lat, data = trek_df, geom = "path", maptype = "terrain",
  color = I("red"), size = I(2), alpha = I(.5)
)



## neat faceting example
########################################

from <- "houston, texas"; to <- "waco, texas"
trek_df <- trek(from, to, alternatives = TRUE)

qmplot(lon, lat, data = trek_df, geom = "path",
  color = route, size = I(2), maptype = "terrain",
  alpha = I(.5)
)

qmplot(lon, lat, data = trek_df, geom = "path",
  color = route, size = I(2), maptype = "terrain",
  zoom = 8
) + facet_grid(. ~ route)





## End(Not run)

dkahle/ggmap documentation built on March 3, 2024, 8:19 a.m.