get_shapes_df: Convert Shape Geometries to GTFS Shape Points Data Frame

In GTFSwizard: Exploring and Manipulating 'GTFS' Files

Convert Shape Geometries to GTFS Shape Points Data Frame

Description

The 'get_shapes_df' function converts a spatial object of shapes (with geometry) into a GTFS-compliant 'shapes' data frame format, detailing latitude, longitude, point sequence, and cumulative distance traveled along each shape.

Usage

get_shapes_df(shape)

Arguments

shape

A spatial ('sf') object containing shapes, with 'shape_id' and geometry information.

Details

The function performs the following steps:

- Validates that the 'shape' object is of class 'sf' and contains a 'shape_id' column.

- Extracts point coordinates from each shape’s geometry, creating a sequence of latitude and longitude points.

- Computes cumulative distances along the shape, using Euclidean distance between consecutive points.

The resulting data frame conforms to the GTFS 'shapes.txt' format. Distances are expressed in meters.

Value

A data frame with columns:

'shape_id'

Unique identifier for each shape.

'shape_pt_lon'

Longitude coordinates of each shape point.

'shape_pt_lat'

Latitude coordinates of each shape point.

'shape_pt_sequence'

Sequence of points along each shape.

'shape_dist_traveled'

Cumulative distance traveled along the shape in meters.

See Also

[GTFSwizard::get_shapes()], [GTFSwizard::get_shapes_sf()]

Examples

# Convert a shape geometry to a GTFS-compliant shapes data frame
shape <- get_shapes_sf(for_rail_gtfs$shapes)
shapes_df <- get_shapes_df(shape = shape)

GTFSwizard documentation built on April 4, 2025, 4:10 a.m.