this is just a sketch! no actual code here yet…

utm

utm is a simple, lightweight R 📦 that has 1 main function:

• utm_zone() - determine UTM zone from longitude and latitude

This returns the UTM zone and epsg as a named list and accepts a list of coordinates as input.

For fun, there is also

• utm_sample_coords() - sample a random lon/lat coordinate on earth

And for folks who live in British Columbia, there is

• utm_bc_stream() - accepts an official gazzetted stream name
• utm_bc_code() - accepts an official BC watershed code

For example, let’s sample a random coordinate and get UTM zone and epsg

# library(utm)
# coords <- utm_sample_coords(4)
# utm_zone(coords)

The table for converting UTM zone to epsg is also provided as a data object

# utm_lookup

A typical use case might be to transform a point to UTM given no knowledge of where it is. This could be done e.g. with the sf :package like this (given this :package: is so small, I didn’t think it is worth including sf as a dependency):

# utm <- sf_point %>%
#   sf::st_zm() %>% # remove Z coord if present
#   sf::st_transform(4326) %>% # ensure that in lat/lon
#   sf::st_coordinates() %>% # get coordinates as list
#   utm_zone() 
# 
# sf_point_utm <- sf::st_transform(sf_point, utm["epsg"])

Note that the special cases of Norway and Svalbard are taken into account in the utm_zone function.