coord2state is a single-file JS library with no dependencies for quickly looking up which state a given latitude and longitude point is in. You can read my blog post about why I built this: Mapping latitude and longitude to country, state, or city
You can install it via NPM:
npm install coord2state
Or include it directly with a CDN:
<script src="https://unpkg.com/coord2state/dist/coord2state.min.js"></script>
Once the script is loaded, simply call getState(lat, lon), like so:
const state = getState(40.7128, -74.0060); // returns "NY"
To generate the JS library, install geopandas and run build_state_lookup.py:
python3 scripts/build_state_lookup.py \
--shapefile tl_2024_us_state.shp \
--template src/coord2state.template.js \
--tolerance 0.01 \
--out dist/coord2state.js
You can then minify it using:
terser dist/coord2state.js \
--compress \
--mangle \
--output dist/coord2state.min.js \
--comments false
The Jupyter notebook for evaluating the borders is benchmark_borders.ipynb
For comparing the vertices, run count_points.py:
python3 scripts/count_points.py
For generating the border comparison visualizations, run visualize_state.py:
python3 scripts/visualize_state.py
open compare.png