GTFSwizard (version 1.1.0)

get_shapes_df: 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)

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.

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.

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)