Public
Edited
Jul 1, 2024
27 stars
Insert cell
Insert cell
cents = d3.ticks(0, 10, 1000)
Insert cell
index = d3.bisect(cents, Math.PI)
Insert cell
[cents[index - 1], cents[index]]
Insert cell
Insert cell
Insert cell
Insert cell
sorted = {
replay;
const sorted = [];
do {
const x = Math.random();
const i = d3.bisect(sorted, x);
sorted.splice(i, 0, x); // insert "x" at rank i, deleting 0 element
yield sorted;
} while (sorted.length < 225);
}
Insert cell
Insert cell
d3.bisect([0, 1, 1, 2], 1)
Insert cell
d3.bisectRight([0, 1, 1, 2], 1)
Insert cell
d3.bisectLeft([0, 1, 1, 2], 1)
Insert cell
Insert cell
numbers = Array.from({length: 1000}, (_, i) => Math.floor(Math.sqrt(i)))
Insert cell
n = 20
Insert cell
pos = [d3.bisectLeft(numbers, n), d3.bisectRight(numbers, n)]
Insert cell
Insert cell
Insert cell
// A synthetic dataset
// to load your own, use data = d3.json(url)
// or data = require("@observablehq/aapl")
data = Array.from(
(function*() {
let date = new Date("2007-04-24"),
close = 98.84;
for (let i = 0; i < 1280; i++) {
if (i % 7 > 5) continue; // ignore 2 days per week
date = new Date(date.setDate(date.getDate() + 1));
close = +(close + Math.random() - 0.485).toFixed(2);
yield { date, close };
}
})()
)
Insert cell
Insert cell
bisect = d3.bisector(d => d.date)
Insert cell
bisect.right(data, new Date(2010, 0, 9))
Insert cell
Insert cell
Insert cell
Insert cell
Insert cell
{
const height = 250;

const chart = d3
.create("svg")
.attr("width", width)
.attr("height", height);

yield chart.node();

const y = d3
.scaleLinear()
.domain([0, 12])
.range([10, height - 10]),
extent = d3.extent(data, d => d.date),
x = d3
.scaleLinear()
.domain(extent)
.range([10, width - 10]);

function X(pos) {
return x(pos < data.length ? data[pos].date : extent[1]);
}

const last = positions.length - 1,
l = positions[last];

chart
.append("line")
.attr("y2", height)
.attr("style", "stroke:#999; stroke-width:0.5; stroke-dasharray: 5 3;")
.attr("x1", X(l))
.attr("x2", X(l));

chart
.append("g")
.selectAll("line")
.data(d3.pairs(positions))
.join("line")
.attr("x1", d => X(d[0]))
.attr("x2", d => X(d[1]))
.attr("y1", (_, i) => y(i))
.attr("y2", (_, i) => y(i + 1))
.style("stroke", "#ccc");

chart
.append("g")
.selectAll("circle")
.data(positions.slice(0, -1))
.join("circle")
.attr("r", 2)
.attr("cx", d => X(d))
.attr("cy", (_, i) => y(i));

chart
.append("circle")
.attr("r", 3)
.attr("cx", X(l))
.attr("cy", y(last))
.style("fill", "red");

chart.on("pointermove click", function(event) {
const m = d3.pointer(event, this);
const date = x.invert(m[0]);
const i = bisect.right(data, date);
mutable lookup = new Date(date);
});
}
Insert cell
positions = [...bisectSteps(data, lookup, d => d.date)]
Insert cell
Insert cell
Insert cell
{
const sorted = [];
const bisector = d3.bisector(d3.descending).right;
do {
const x = ((Math.random() * 1000) | 0) / 1000;
const i = bisector(sorted, x);
sorted.splice(i, 0, x); // inserts "x" at rank i, deleting 0 element
yield sorted;
} while (sorted.length < 255);
}
Insert cell
Insert cell
Insert cell
d3.bisect(cents, 4, 500, 700) // try different bounds!
Insert cell
d3.bisect(cents, 6, 500, 700)
Insert cell
d3.bisect(cents, 8, 500, 700)
Insert cell
Insert cell
Insert cell
function* bisectSteps(a, x, accessor = d => d) {
let lo = 0,
hi = a.length;
while (lo < hi) {
var mid = (lo + hi) >>> 1;
yield mid;
if (d3.ascending(accessor(a[mid]), x) < 0) lo = mid + 1;
else hi = mid;
}
yield lo;
}
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