chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, 975, 610]);
svg.append("g")
.attr("transform", "translate(610,20)")
.append(() => legend(Object.assign({color, title, width: 260},legendAttributes)));
svg.append("g")
.selectAll("path")
.data(topojson.feature(us, us.objects.counties).features)
.join("path")
.attr("fill", d => color(dataFipsAndValueMap.get(d.id)))
.attr("d", path)
.append("title")
.text(d => `${d.properties.name}, ${states.get(d.id.slice(0, 2)).name}
${ (dataFipsAndValueMap.get(d.id)==undefined) ?
"No Data" :
format(dataFipsAndValueMap.get(d.id))}`);
svg.append("path")
.datum(topojson.mesh(us, us.objects.states, (a, b) => a !== b))
.attr("fill", "none")
.attr("stroke", "white")
.attr("stroke-linejoin", "round")
.attr("d", path);
return svg.node();
}
legendAttributes = ({ tickFormat: ".1f" })
dataFipsAndValueArray = d3.csvParse(await FileAttachment("unemployment-x.csv").text(), ({id, rate}) => [id, +rate])
dataFipsAndValueMap = new Map(dataFipsAndValueArray)
title= "Unemployment rate (%)"
color = d3.scaleQuantize([1, 10], d3.schemeBlues[9])
path = d3.geoPath()
format = d => `${d}%`
states = new Map(us.objects.states.geometries.map(d => [d.id, d.properties]))
us = FileAttachment("counties-albers-10m.json").json()
topojson = require("topojson-client@3")
d3 = require("d3@6")
import {legend} from "@d3/color-legend"
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
