valh (version 0.2.0)

vl_locate: Get the nearest point on the road network

Description

This function interfaces with the locate Valhalla service.

Usage

vl_locate(
  loc,
  verbose = FALSE,
  costing = "auto",
  costing_options = list(),
  server = getOption("valh.server")
)

Value

If there is only one input point, return a single sf object containing the nearest point(s) on the road network. If there is more than one input point, return a list of sf objects, one for each input point.

Arguments

loc

one (or multiples) point(s) to snap to the street network. loc can be:

• a vector of coordinates (longitude and latitude, WGS 84),

• a data.frame of longitudes and latitudes (WGS 84),

• a matrix of longitudes and latitudes (WGS 84),

• an sfc object of type POINT,

• an sf object of type POINT.

verbose

logical indicating whether to return additional information.

costing

costing model to use.

costing_options

list of options to use with the costing model (see https://valhalla.github.io/valhalla/api/turn-by-turn/api-reference/#costing-options for more details about the options available for each costing model).

server

URL of the Valhalla server.

Examples

if (FALSE) {
# Inputs are data frames
apotheke.df <- read.csv(system.file("csv/apotheke.csv", package = "valh"))

loc <- apotheke.df[1, c("lon", "lat")]

# Ask for the nearest point on the road network at this point
# using "auto" costing model
on_road_1 <- vl_locate(loc = loc)

# Inputs are sf points
library(sf)
apotheke.sf <- st_read(system.file("gpkg/apotheke.gpkg", package = "valh"),
  quiet = TRUE
)

# Ask for one point
locsf1 <- apotheke.sf[1, ]
# The result is a single sf object
on_road_2 <- vl_locate(loc = locsf1)

# Ask for multiple points
locsf2 <- apotheke.sf[1:3, ]
# The result is a list of sf objects
on_road_3 <- vl_locate(loc = locsf2)
}