30:T47f,chart = { const svg = d3.create("svg") .attr("viewBox", [0, 0, 960, 600]); svg.append("path") .datum(topojson.merge(us, us.objects.lower48.geometries)) .attr("fill", "#ddd") .attr("d", d3.geoPath()); svg.append("path") .datum(topojson.mesh(us, us.objects.lower48, (a, b) => a !== b)) .attr("fill", "none") .attr("stroke", "white") .attr("stroke-linejoin", "round") .attr("d", d3.geoPath()); const g = svg.append("g") .attr("fill", "none") .attr("stroke", "black"); const dot = g.selectAll("circle") .data(data) .join("circle") .attr("transform", d => `translate(${d})`); svg.append("circle") .attr("fill", "blue") .attr("transform", `translate(${data[0]})`) .attr("r", 3); let previousDate = -Infinity; return Object.assign(svg.node(), { update(date) { dot // enter .filter(d => d.date > previousDate && d.date <= date) .transition().attr("r", 3); dot // exit .filter(d => d.date <= previousDate && d.date > date) .transition().attr("r", 0); previousDate = date; } }); }31:[{"id":"ce607f28cac52d17fe11f7a2dcff0a21c3b74465957841bc8ac390b900fae923b824a86762af12f1a96e0213d613636092a65c611bd6b256b4e729106d4612fe","href":"https://static.observableusercontent.com/files/ce607f28cac52d17fe11f7a2dcff0a21c3b74465957841bc8ac390b900fae923b824a86762af12f1a96e0213d613636092a65c611bd6b256b4e729106d4612fe","name":"walmart.tsv","type":"text/tab-separated-values","lastModified":1622591253035.14,"size":99253}] 2e:{"title":"Walmart’s growth","cells":[{"id":0,"value":"

Walmart’s growth

D3 › Gallery

\n\n# Walmart’s growth\n\nThis animation shows the expansion of Walmart over the last fifty years. On July 2, 1962 in [Rogers, Arkansas](https://en.wikipedia.org/wiki/Rogers,_Arkansas), the first Walton’s opened. [This dataset](http://users.econ.umn.edu/~holmes/data/WalMart/index.html) from 2006 includes about 3,100 Walmart locations in the contiguous United States.","pinned":false,"hidden":false,"mode":"md"},{"id":288,"value":"viewof date = Scrubber(d3.utcWeek.every(2).range(...d3.extent(data, d => d.date)), {format: d3.utcFormat(\"%Y %b %-d\"), loop: false})","pinned":false,"hidden":false,"mode":"ojs"},{"id":14,"value":"$30","pinned":true,"hidden":false,"mode":"ojs"},{"id":296,"value":"update = chart.update(date)","pinned":true,"hidden":false,"mode":"ojs"},{"id":16,"value":"data = (await FileAttachment(\"walmart.tsv\").tsv())\n .map(d => {\n const p = projection(d);\n p.date = parseDate(d.date);\n return p;\n })\n .sort((a, b) => a.date - b.date)","pinned":true,"hidden":false,"mode":"ojs"},{"id":275,"value":"parseDate = d3.utcParse(\"%m/%d/%Y\")","pinned":true,"hidden":false,"mode":"ojs"},{"id":279,"value":"projection = d3.geoAlbersUsa().scale(1280).translate([480, 300])","pinned":true,"hidden":false,"mode":"ojs"},{"id":8,"value":"us = {\n const us = await d3.json(\"https://cdn.jsdelivr.net/npm/us-atlas@1/us/10m.json\");\n us.objects.lower48 = {\n type: \"GeometryCollection\",\n geometries: us.objects.states.geometries.filter(d => d.id !== \"02\" && d.id !== \"15\")\n };\n return us;\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":283,"value":"import {Scrubber} from \"@mbostock/scrubber\"","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W31","stdlib":"1","titling":"auto"}