latlon2epsg: Transform Spatial Data to a Local UTM Coordinate System

In GTFSwizard: Exploring and Manipulating 'GTFS' Files

Transform Spatial Data to a Local UTM Coordinate System

Description

The 'latlon2epsg' function determines the appropriate UTM (Universal Transverse Mercator) EPSG code for a given 'sf' object based on its centroid's latitude and longitude. It then transforms the object to the identified coordinate reference system (CRS).

Usage

latlon2epsg(sf_obj)

Arguments

sf_obj

An 'sf' object representing spatial features. This object must have a valid CRS with latitude and longitude coordinates.

Details

The function calculates the geographic centroid of the input spatial object and determines its latitude and longitude. Based on the latitude:

Latitudes above 84°

The object is transformed to EPSG:3413 (North Pole).

Latitudes below -80°

The object is transformed to EPSG:3031 (South Pole).

Latitudes between -80° and 84°

The function calculates the UTM zone based on longitude and transforms the object to the appropriate UTM EPSG code (EPSG:326XX for the Northern Hemisphere, EPSG:327XX for the Southern Hemisphere).

Value

An 'sf' object transformed to the appropriate UTM coordinate reference system.

Note

The function requires that the input 'sf' object already has a valid CRS defined (e.g., WGS84).

See Also

[sf::st_transform()], [sf::st_centroid()], [sf::st_union()]

Examples

latlon2epsg(get_shapes_sf(for_bus_gtfs)$shapes)

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