Public
Edited
May 6, 2020
3 forks
8 stars
chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
svg.append("g")
.call(xAxis);
svg.append("g")
.selectAll("circle")
.data(dodge(data))
.join("circle")
.attr("cx", d => d.x)
.attr("cy", d => height - margin.bottom - padding - d.y)
.attr("r", d => d.r)
.append("title")
.text(d => d.data.name);
return svg.node();
}
dodge = (data) => {
const circles = data.map(d => ({x: x(d.value), r: r(d.population), data: d})).sort((a, b) => b.r - a.r);
const epsilon = 1e-3;
let head = null, tail = null, queue = null;
// Returns true if circle ⟨x,y⟩ intersects with any circle in the queue.
function intersects(x, y, r) {
let a = head;
while (a) {
const radius2 = (a.r + r + padding) ** 2;
if (radius2 - epsilon > (a.x - x) ** 2 + (a.y - y) ** 2) {
return true;
}
a = a.next;
}
return false;
}
// Place each circle sequentially.
for (const b of circles) {
// Choose the minimum non-intersecting tangent.
if (intersects(b.x, b.y = b.r, b.r)) {
let a = head;
b.y = Infinity;
do {
let y = a.y + Math.sqrt((a.r + b.r + padding) ** 2 - (a.x - b.x) ** 2);
if (y < b.y && !intersects(b.x, y, b.r)) b.y = y;
a = a.next;
} while (a);
}
// Add b to the queue.
b.next = null;
if (head === null) {
head = tail = b;
queue = head;
} else tail = tail.next = b;
}
return circles;
}
data = d3.csvParse(await FileAttachment("fertility_and_population.csv").text(), ({Entity: name, Fertility: value, Population: population}) => ({name, value: +value, population: +population}))
r = population => Math.max(1.5, Math.sqrt(population) / 900)
x = d3.scaleLinear()
.domain(d3.extent(data, d => d.value))
.range([margin.left, width - margin.right])
xAxis = g => g
.attr("transform", `translate(0,${height - margin.bottom})`)
.call(d3.axisBottom(x).tickSizeOuter(0))
height = 300
padding = 1.5
margin = ({top: 20, right: 20, bottom: 30, left: 20})
d3 = require("d3@5")
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.
