vl.markGeoshape({stroke:'gray', strokewidth:1})
.data(vl.json(seattleZipCodes).property("features"))
.transform(
vl.lookup("properties.GEOID10").from(
vl.data(seattleHousePricesByZipCode).key("ZipCode").fields(["MedianHousePrice"])
)
)
.encode(
vl.color().fieldQ('MedianHousePrice').title("Median House Price"),
vl.tooltip([{field:'properties.GEOID10', type:'ordinal', title:'Zip Code'},
{field:'MedianHousePrice', type:'quantitative', title:'Median House Price'}])
)
.project(vl.projection('identity').reflectY(true))
.title("Median House Prices in Seattle by Zip Code")
.width(500)
.height(500)
.render()