This is where I prototype and experiment
Published
Edited
Jun 30, 2020
1 star
chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
svg.append("line")
.attr('x1', 0)
.attr('x2', width)
.attr('y1', height / 2)
.attr('y2', height / 2)
.attr('stroke', 'black');
svg.append("g")
.selectAll("circle")
.data(dodge(data, radius * 2 + padding))
.join("circle")
.attr("cx", d => d.x)
.attr("cy", d => height / 2 - radius - padding - d.y)
.attr("r", radius)
.append("title")
.text(d => d.data.name);
svg.append("g")
.selectAll("circle")
.data(dodge(data, radius * 2 + padding))
.join("circle")
.attr("cx", d => d.x)
.attr("cy", d => height / 2 + radius + padding + d.y)
.attr("r", radius)
.attr("fill", "steelblue")
.append("title")
.text(d => d.data.name);
return svg.node();
}
dodge = (data, radius) => {
const radius2 = radius ** 2;
const circles = data.map(d => ({x: x(d.value), data: d})).sort((a, b) => a.x - b.x);
const epsilon = 1e-3;
let head = null, tail = null;
// Returns true if circle ⟨x,y⟩ intersects with any circle in the queue.
function intersects(x, y) {
let a = head;
while (a) {
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) {
// Remove circles from the queue that can’t intersect the new circle b.
while (head && head.x < b.x - radius2) head = head.next;
// Choose the minimum non-intersecting tangent.
if (intersects(b.x, b.y = 0)) {
let a = head;
b.y = Infinity;
do {
let y = a.y + Math.sqrt(radius2 - (a.x - b.x) ** 2);
if (y < b.y && !intersects(b.x, y)) b.y = y;
a = a.next;
} while (a);
}
// Add b to the queue.
b.next = null;
if (head === null) head = tail = b;
else tail = tail.next = b;
}
return circles;
}
data = d3.csvParse(await FileAttachment("cars-2.csv").text(), ({Name: name, Weight_in_lbs: value}) => ({name, value: +value}))
x = d3.scaleLinear()
.domain(d3.extent(data, d => d.value))
.range([margin.left, width - margin.right])
height = 240
radius = 3
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.
