mutable min = 0
mutable max = 10.5
mutable lower_color = "white"
mutable higher_color = "blue"
mutable legend_title = "normalized counts"
VertContLegend = legend({
color: d3.scaleSequential([mutable min, mutable max], [mutable lower_color, mutable higher_color]),
title: mutable legend_title
})
legend({
color: d3.scaleSequentialSqrt([0, 1], d3.interpolateTurbo),
title: "Speed (kts)"
})
legend({
color: d3.scaleDiverging([-0.1, 0, 0.1], d3.interpolatePiYG),
title: "Daily change",
tickFormat: "+%"
})
legend({
color: d3.scaleDivergingSqrt([-0.1, 0, 0.1], d3.interpolateRdBu),
title: "Daily change",
tickFormat: "+%"
})
legend({
color: d3.scaleSequentialLog([1, 100], d3.interpolateBlues),
title: "Energy (joules)",
ticks: 10,
tickFormat: ".0s"
})
legend({
color: d3.scaleSequentialQuantile(Array.from({length: 100}, () => Math.random() ** 2), d3.interpolateBlues),
title: "Quantile",
tickFormat: ".2f"
})
legend({
color: d3.scaleSqrt([-100, 0, 100], ["blue", "white", "red"]),
title: "Temperature (°C)"
})
legend({
color: d3.scaleQuantize([1, 10], d3.schemePurples[9]),
title: "Unemployment rate (%)"
})
legend({
color: d3.scaleQuantile(d3.range(1000).map(d3.randomNormal(100, 20)), d3.schemeSpectral[9]),
title: "Height (cm)",
tickFormat: ".0f"
})
legend({
color: d3.scaleThreshold([2.5, 3.1, 3.5, 3.9, 6, 7, 8, 9.5], d3.schemeRdBu[9]),
title: "Unemployment rate (%)",
tickSize: 0
})
legend({
color: d3.scaleOrdinal(["<10", "10-19", "20-29", "30-39", "40-49", "50-59", "60-69", "70-79", "≥80"], d3.schemeSpectral[10]),
title: "Age (years)",
tickSize: 0
})
swatches({
color: d3.scaleOrdinal(["blueberries", "oranges", "apples"], d3.schemeCategory10)
})
swatches({
color: d3.scaleOrdinal(["Wholesale and Retail Trade", "Manufacturing", "Leisure and hospitality", "Business services", "Construction", "Education and Health", "Government", "Finance", "Self-employed", "Other"], d3.schemeTableau10),
columns: "280px",
swatchSize: 20
})
function legend({
color,
title,
tickSize = 6,
width = 36 + tickSize,
height = 320,
marginTop = 20,
marginRight = 10 + tickSize,
marginBottom = 20,
marginLeft = 5,
ticks = height / 64,
tickFormat,
tickValues
} = {}) {
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [0, 0, width, height])
.style("overflow", "visible")
.style("display", "block");
let tickAdjust = g => g.selectAll(".tick line").attr("x1", marginLeft - width + marginRight);
let x;
// Continuous
if (color.interpolate) {
const n = Math.min(color.domain().length, color.range().length);
x = color.copy().rangeRound(d3.quantize(d3.interpolate(height - marginBottom, marginTop), n));
svg.append("image")
.attr("x", marginLeft)
.attr("y", marginTop)
.attr("width", width - marginLeft - marginRight)
.attr("height", height - marginTop - marginBottom)
.attr("preserveAspectRatio", "none")
.attr("xlink:href", ramp(color.copy().domain(d3.quantize(d3.interpolate(0, 1), n))).toDataURL());
}
// Sequential
else if (color.interpolator) {
x = Object.assign(color.copy()
.interpolator(d3.interpolateRound(height - marginBottom, marginTop)),
{range() { return [height - marginBottom, marginTop]; }});
svg.append("image")
.attr("x", marginLeft)
.attr("y", marginTop)
.attr("width", width - marginLeft - marginRight)
.attr("height", height - marginTop - marginBottom)
.attr("preserveAspectRatio", "none")
.attr("xlink:href", ramp(color.interpolator()).toDataURL());
// scaleSequentialQuantile doesn’t implement ticks or tickFormat.
if (!x.ticks) {
if (tickValues === undefined) {
const n = Math.round(ticks + 1);
tickValues = d3.range(n).map(i => d3.quantile(color.domain(), i / (n - 1)));
}
if (typeof tickFormat !== "function") {
tickFormat = d3.format(tickFormat === undefined ? ",f" : tickFormat);
}
}
}
// Threshold
else if (color.invertExtent) {
const thresholds
= color.thresholds ? color.thresholds() // scaleQuantize
: color.quantiles ? color.quantiles() // scaleQuantile
: color.domain(); // scaleThreshold
const thresholdFormat
= tickFormat === undefined ? d => d
: typeof tickFormat === "string" ? d3.format(tickFormat)
: tickFormat;
x = d3.scaleLinear()
.domain([-1, color.range().length - 1])
.rangeRound([height - marginBottom, marginTop]);
svg.append("g")
.selectAll("rect")
.data(color.range())
.join("rect")
.attr("y", (d, i) => x(i))
.attr("x", marginLeft)
.attr("height", (d, i) => x(i - 1) - x(i))
.attr("width", width - marginRight - marginLeft)
.attr("fill", d => d);
tickValues = d3.range(thresholds.length);
tickFormat = i => thresholdFormat(thresholds[i], i);
}
// Ordinal
else {
x = d3.scaleBand()
.domain(color.domain())
.rangeRound([height - marginBottom, marginTop]);
svg.append("g")
.selectAll("rect")
.data(color.domain())
.join("rect")
.attr("y", x)
.attr("x", marginLeft)
.attr("height", Math.max(0, x.bandwidth() - 1))
.attr("width", width - marginLeft - marginRight)
.attr("fill", color);
tickAdjust = () => {};
}
svg.append("g")
.attr("transform", `translate(${width - marginRight},0)`)
.call(d3.axisRight(x)
.ticks(ticks, typeof tickFormat === "string" ? tickFormat : undefined)
.tickFormat(typeof tickFormat === "function" ? tickFormat : undefined)
.tickSize(tickSize)
.tickValues(tickValues))
.call(tickAdjust)
.call(g => g.select(".domain").remove())
.call(g => g.append("text")
.attr("x", marginLeft - width + marginRight)
.attr("y", 0)
.attr("fill", "currentColor")
.attr("text-anchor", "start")
.attr("font-weight", "bold")
.attr("class", "title")
.text(title));
return svg.node();
}
function entity(character) {
return `&#${character.charCodeAt(0).toString()};`;
}
function ramp(color, n = 256) {
const canvas = DOM.canvas(1, n);
const context = canvas.getContext("2d");
for (let i = 0; i < n; ++i) {
context.fillStyle = color(i / (n - 1));
context.fillRect(0, n-i, 1, 1);
}
return canvas;
}
d3 = require("d3@6")
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.