chart = Scatterplot(cars, {
x: d => d.mpg,
y: d => d.hp,
title: d => d.name,
xLabel: "Miles per gallon →",
yLabel: "↑ Horsepower",
stroke: "steelblue",
width,
height: 600
})
cars = FileAttachment("mtcars.csv").csv({typed: true})
// Copyright 2021 Observable, Inc.
// Released under the ISC license.
// https://observablehq.com/@d3/scatterplot
function Scatterplot(data, {
x = ([x]) => x, // given d in data, returns the (quantitative) x-value
y = ([, y]) => y, // given d in data, returns the (quantitative) y-value
r = 3, // (fixed) radius of dots, in pixels
title, // given d in data, returns the title
marginTop = 20, // top margin, in pixels
marginRight = 30, // right margin, in pixels
marginBottom = 30, // bottom margin, in pixels
marginLeft = 40, // left margin, in pixels
inset = r * 2, // inset the default range, in pixels
insetTop = inset, // inset the default y-range
insetRight = inset, // inset the default x-range
insetBottom = inset, // inset the default y-range
insetLeft = inset, // inset the default x-range
width = 640, // outer width, in pixels
height = 400, // outer height, in pixels
xType = d3.scaleLinear, // type of x-scale
xDomain, // [xmin, xmax]
xRange = [marginLeft + insetLeft, width - marginRight - insetRight], // [left, right]
yType = d3.scaleLinear, // type of y-scale
yDomain, // [ymin, ymax]
yRange = [height - marginBottom - insetBottom, marginTop + insetTop], // [bottom, top]
xLabel, // a label for the x-axis
yLabel, // a label for the y-axis
xFormat, // a format specifier string for the x-axis
yFormat, // a format specifier string for the y-axis
fill = "none", // fill color for dots
stroke = "currentColor", // stroke color for the dots
strokeWidth = 1.5, // stroke width for dots
halo = "#fff", // color of label halo
haloWidth = 3 // padding around the labels
} = {}) {
// Compute values.
const X = d3.map(data, x);
const Y = d3.map(data, y);
const T = title == null ? null : d3.map(data, title);
const I = d3.range(X.length).filter(i => !isNaN(X[i]) && !isNaN(Y[i]));
// Compute default domains.
if (xDomain === undefined) xDomain = d3.extent(X);
if (yDomain === undefined) yDomain = d3.extent(Y);
// Construct scales and axes.
const xScale = xType(xDomain, xRange);
const yScale = yType(yDomain, yRange);
const xAxis = d3.axisBottom(xScale).ticks(width / 80, xFormat);
const yAxis = d3.axisLeft(yScale).ticks(height / 50, yFormat);
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [0, 0, width, height])
.attr("style", "max-width: 100%; height: auto; height: intrinsic;");
svg.append("g")
.attr("transform", `translate(0,${height - marginBottom})`)
.call(xAxis)
.call(g => g.select(".domain").remove())
.call(g => g.selectAll(".tick line").clone()
.attr("y2", marginTop + marginBottom - height)
.attr("stroke-opacity", 0.1))
.call(g => g.append("text")
.attr("x", width)
.attr("y", marginBottom - 4)
.attr("fill", "currentColor")
.attr("text-anchor", "end")
.text(xLabel));
svg.append("g")
.attr("transform", `translate(${marginLeft},0)`)
.call(yAxis)
.call(g => g.select(".domain").remove())
.call(g => g.selectAll(".tick line").clone()
.attr("x2", width - marginLeft - marginRight)
.attr("stroke-opacity", 0.1))
.call(g => g.append("text")
.attr("x", -marginLeft)
.attr("y", 10)
.attr("fill", "currentColor")
.attr("text-anchor", "start")
.text(yLabel));
if (T) svg.append("g")
.attr("font-family", "sans-serif")
.attr("font-size", 10)
.attr("stroke-linejoin", "round")
.attr("stroke-linecap", "round")
.selectAll("text")
.data(I)
.join("text")
.attr("dx", 7)
.attr("dy", "0.35em")
.attr("x", i => xScale(X[i]))
.attr("y", i => yScale(Y[i]))
.text(i => T[i])
.call(text => text.clone(true))
.attr("fill", "none")
.attr("stroke", halo)
.attr("stroke-width", haloWidth);
svg.append("g")
.attr("fill", fill)
.attr("stroke", stroke)
.attr("stroke-width", strokeWidth)
.selectAll("circle")
.data(I)
.join("circle")
.attr("cx", i => xScale(X[i]))
.attr("cy", i => yScale(Y[i]))
.attr("r", r);
return svg.node();
}
import {howto, altplot} from "@d3/example-components"
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.
