ibis pyarrow UDFs

ibis-duckdb-udfs.py

import ibis
from ibis import _
import leafmap.maplibregl as leafmap

con = ibis.duckdb.connect(extensions=["spatial"])
states = con.read_geo("https://raw.githubusercontent.com/PublicaMundi/MappingAPI/master/data/geojson/us-states.json")

## Add a fill-color column
import matplotlib.cm as cm
import matplotlib.colors as mcolors

import pyarrow

# .Float64(nullable=True)
@ibis.udf.scalar.pyarrow
def viridis(x: pyarrow.float64()) -> str:
    rgb = cm.viridis(x)
    return mcolors.to_hex(rgb)

  
# nope, custom udf function fails  
column = "density"
gdf = (states
       .mutate(norm = _[column] / _[column].max()) # normalize counts to between 0-1
       .mutate(fill = viridis(_.norm))
       .execute()
      )