chart = {
const svg = d3.select(DOM.svg(width, height))
.style("width", "100%")
.style("height", "auto")
svg.append("path")
.datum(topojson.merge(london, london.objects.boroughs.geometries))
.attr("fill", "#ddd")
.attr("d", d3.geoPath(projection))
svg.append("path")
.datum(topojson.mesh(london, london.objects.boroughs, (a, b) => a !== b))
.attr("fill", "none")
.attr("stroke", "white")
.attr("stroke-linejoin", "round")
.attr("d", d3.geoPath(projection))
svg.append("g")
.attr("fill", "none")
.attr("stroke", "black")
.attr("pointer-events", "all")
.selectAll("path")
.data(d3.geoVoronoi().polygons(centroids).features)
.enter().append("path")
.attr("d", d3.geoPath(projection))
.append("title")
svg.append("path")
.datum({type:"FeatureCollection", features: centroids})
.attr("d", d3.geoPath(projection).pointRadius(1.5));
return svg.node()
}
projection = d3.geoMercator()
.center([-0.1, 51.49])
.scale(Math.pow(2, 17) / (2 * Math.PI))
.translate([width / 2, height / 2])
viewof width = html`<input type="number" value="400" min="120" max="800" step="20" style="width: 5em">`
viewof height = html`<input type="number" value="400" min="100" max="600" step="20" style="width: 5em">`
centroids = d3.json('https://vega.github.io/vega-datasets/data/londonCentroids.json').then(data => data.map(d => ({
type: "Feature",
properties: {'name' :d.name},
geometry: {
type: "Point",
coordinates: [d.cx, d.cy]
}
})))
london = d3.json('https://vega.github.io/vega-datasets/data/londonBoroughs.json')
// london = d3.json('https://unpkg.com/jpn-atlas@1/japan/japan.json')
topojson = require("topojson-client@3")
d3 = require("d3@5", "d3-geo-voronoi@1")
canvas = {
const context = DOM.context2d(850, 680)
const path = d3.geoPath().context(context)
context.lineWidth = 0.5
context.strokeStyle = "#aaa"
context.beginPath()
path(topojson.mesh(london))
context.stroke()
context.strokeStyle = "#000"
context.beginPath()
path(topojson.mesh(london, london.objects.boroughs, (a, b) => a !== b))
path(topojson.feature(london, london.objects.boroughs))
context.stroke()
return context.canvas
}
london
svg = {
const svg = d3.select(DOM.svg(850, 680))
const path = d3.geoPath()
svg.attr("fill", "none")
.attr("stroke", "#000")
.attr("stroke-linejoin", "round")
.attr("stroke-linecap", "round")
svg.append("path")
.attr("stroke", "#aaa")
.attr("stroke-width", 0.5)
.attr("d", path(topojson.mesh(london, london.objects.boroughs,
(a, b) => a !== b)))
svg.append("path")
.attr("stroke-width", 0.5)
.attr("d", path(topojson.mesh(london, london.objects.boroughs, (a, b) => a !== b)))
return svg.node()
}
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