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Get the distances of stops along routes

Source: R/gtfs_helpers.R
get_stop_distances.Rd

This function returns the linear distance of each stop along a route shape, starting from the route's beginning terminal. Unless a shape_geometry is provided, stops will be project onto all shape_ids that serve them. If a shape_geometry is provided, the function will look only for stops served by that shape.

Usage

get_stop_distances(gtfs, shape_geometry = NULL, project_crs = 4326)

Arguments

gtfs

A tidygtfs object.

shape_geometry

Optional. The SF object to project onto. Must include the field shape_id. See get_shape_geometry(). Default is NULL, where all shapes in gtfs will be used.

project_crs

Optional. A numeric EPSG identifer indicating the coordinate system to use for spatial calculations. Consider setting to a Euclidian projection, such as the appropriate UTM zone. Default is 4326 (WGS 84 ellipsoid).

Value

A dataframe containing stop_id, the shape_id it was projected onto, and distance, in units of the spatial projection (e.g., meters if using WGS UTM).

Examples

# Set my parameters
my_shape <- "804EB_RC_221121"
my_crs <- 32611
my_route <- "804"
my_dir <- 0

# Get needed GTFS data
lineE_gtfs <- filter_by_route(gtfs = lacmta_gtfs, route_ids = my_route,
                              dir_id = 0)
lineE_shape <- get_shape_geometry(gtfs = lacmta_gtfs, shape = my_shape,
                                  project_crs = my_crs)

# Run stop distances function
lineE_stop_dists <- get_stop_distances(gtfs = lineE_gtfs,
                                       shape_geometry = lineE_shape,
                                       project_crs = my_crs) %>%
   dplyr::select(-c(stop_desc, stop_url, tpis_name, location_type))
head(lineE_stop_dists)
#> # A tibble: 6 × 6
#>   stop_id stop_code stop_name                   parent_station shape_id distance
#>   <chr>   <chr>     <chr>                       <chr>          <chr>       <dbl>
#> 1 80121   80121     Pico Station                80121S         804EB_R…   23454.
#> 2 80122   80122     7th Street / Metro Center … 80122S         804EB_R…   24556.
#> 3 80123   80123     LATTC / Ortho Institute St… 80123S         804EB_R…   21989.
#> 4 80124   80124     Jefferson / USC Station     80124S         804EB_R…   21105.
#> 5 80125   80125     Expo Park / USC Station     80125S         804EB_R…   20157.
#> 6 80126   80126     Expo / Vermont Station      80126S         804EB_R…   19621.