"""
One Dot Per Zipcode
-----------------------
This example shows a geographical plot with one dot per zipcode.
"""
# category: geographic
import altair as alt
from altair.expr import datum, substring
from vega_datasets import data
zipcodes = data.zipcodes.url
chart = alt.Chart(zipcodes).mark_circle(size=3).encode(
longitude='longitude:Q', latitude='latitude:Q',
color='digit:N').properties(projection={
'type': 'albersUsa'
},
width=650,
height=400).transform_calculate(
"digit", substring(datum.zip_code, 0, 1))
"""
One Dot Per Zipcode
-----------------------
This example shows a geographical plot with one dot per zipcode.
"""
# category: maps
import altair as alt
from altair.expr import datum, substring
from vega_datasets import data
zipcodes = data.zipcodes.url
alt.Chart(zipcodes).mark_circle(size=3).encode(
longitude='longitude:Q', latitude='latitude:Q',
color='digit:N').project(type='albersUsa').properties(
width=650,
height=400).transform_calculate("digit",
substring(datum.zip_code, 0, 1))