Published
Edited
Oct 16, 2021
Insert cell
# Basics
Insert cell
x = d3.scaleUtc()
.domain(d3.extent(data, d => d.date))
.range([margin.left, width - margin.right])
Insert cell
y = d3.scaleLinear()
.domain([0, d3.max(data, d => d.numconf)])
.range([height - margin.bottom, margin.top])
Insert cell
arc = d3.arc()
.innerRadius(210)
.outerRadius(310)
.startAngle(([startAngle, endAngle]) => startAngle)
.endAngle(([startAngle, endAngle]) => endAngle)
Insert cell
arc([Math.PI / 2, Math.PI])
Insert cell
viewof n = {
const form = html`<form style="font: 12px var(--sans-serif); display: flex; align-items: center; min-height: 33px;">
<label style="display: block;">
<input name="input" type="range" min="1" max="50" value="12" step="1" style="width: 180px;">
n = <output name="output"></output>
</label>
</form>`;
form.oninput = () => form.output.value = form.value = form.input.valueAsNumber;
form.oninput();
return form;
}
Insert cell
html`<svg viewBox="-320 -320 640 640" style="max-width: 640px;">
${Array.from({length: n}, (_, i) => svg`<path stroke="black" fill="${d3.interpolateRainbow(i / n)}" d="${arc([i / n * 2 * Math.PI, (i + 1) / n * 2 * Math.PI])}"></path>`)}
</svg>`
Insert cell
pieArcData = d3.pie()
.value(d => d.numconf)
(data)
Insert cell
vl = require('@observablehq/vega-lite')
Insert cell
margin = ({top: 20, right: 0, bottom: 0, left: 150})
Insert cell
height = 240
Insert cell
xAxis = (g, x) => g
.attr("transform", `translate(0,${margin.top})`)
.call(d3.axisTop(x).ticks(width / 80, "%"))
.call(g => (g.selection ? g.selection() : g).select(".domain").remove())
Insert cell
yAxis = (g, y) => g
.attr("transform", `translate(${margin.left},0)`)
.call(d3.axisLeft(y).tickSizeOuter(0))
Insert cell
data = FileAttachment("covid19-data@1.csv").csv()
Insert cell
d3 = require("d3@6")
Insert cell

One platform to build and deploy the best data apps

Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.
Learn more