Published
Edited
Aug 27, 2020
24 stars
Insert cell
Insert cell
Insert cell
function* randoms(n) {
for (let i = 0; i < n; ++i) {
yield Math.random();
}
}
Insert cell
Insert cell
d3.min(randoms(100))
Insert cell
d3.sum(randoms(100))
Insert cell
d3.extent(randoms(100))
Insert cell
Insert cell
d3.min(new Set([1, 4, 3, 2]))
Insert cell
d3.min(new Map([["foo", 10], ["bar", 2]]).values())
Insert cell
Insert cell
d3.cross(
["small", "large"],
["caf", "decaf"],
["skim", "whole", "almond"],
["latte", "cappucino"],
(...parts) => parts.join(" ")
)
Insert cell
Insert cell
data = [
{name: "jim", amount: "34.0", date: "11/12/2015"},
{name: "carl", amount: "120.11", date: "11/12/2015"},
{name: "stacy", amount: "12.01", date: "01/04/2016"},
{name: "stacy", amount: "34.05", date: "01/04/2016"}
]
Insert cell
d3.group(data, d => d.name)
Insert cell
Insert cell
d3.group(data, d => d.name, d => d.date)
Insert cell
Insert cell
d3.rollup(data, v => v.length, d => d.name, d => d.date)
Insert cell
d3.rollup(data, v => d3.sum(v, d => d.amount), d => d.name)
Insert cell
Insert cell
{
const values = Float64Array.from({length: 1e6}, Math.random);
const i = values.length >> 1;
d3.quickselect(values, i);
return values[i];
}
Insert cell
Insert cell
Insert cell
d3 = require("d3-array@2")
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