gtfstools (version 1.4.0)

convert_sf_to_shapes: Convert a simple feature object into a shapes table

Description

Converts a LINESTRING sf object into a GTFS shapes table.

Usage

convert_sf_to_shapes(sf_shapes, shape_id = NULL, calculate_distance = TRUE)

Value

A data.table representing a GTFS shapes table.

Arguments

sf_shapes

A LINESTRING sf associating each shape_ids to a geometry. This object must use CRS WGS 84 (EPSG code 4326).

shape_id

A character vector specifying the shape_ids to be converted. If NULL (the default), all shapes are converted.

calculate_distance

A logical. Whether to calculate and populate the shape_dist_traveled column. This column is used to describe the distance along the shape from each one of its points to its first point. Defaults to TRUE.

Examples

# \dontshow{
  old_dt_threads <- data.table::setDTthreads(1)
  on.exit(data.table::setDTthreads(old_dt_threads), add = TRUE)
# }
data_path <- system.file("extdata/spo_gtfs.zip", package = "gtfstools")
gtfs <- read_gtfs(data_path)

# first converting existing shapes table into a sf object
shapes_sf <- convert_shapes_to_sf(gtfs)
head(shapes_sf)

# by default converts all shapes
result <- convert_sf_to_shapes(shapes_sf)
result

# shape_id argument controls which shapes are converted
result <- convert_sf_to_shapes(shapes_sf, shape_id = c("17846", "17847"))
result

# calculate_distance argument controls whether to calculate
# shape_dist_traveled or not
result <- convert_sf_to_shapes(shapes_sf, calculate_distance = TRUE)
result