chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
const brush = d3.brushX()
.extent([[margin.left, margin.top], [width - margin.right, height - margin.bottom]])
.on("start brush end", brushed);
const circle = svg.append("g")
.attr("fill-opacity", 0.2)
.selectAll("circle")
.data(Float64Array.from({length: 800}, Math.random))
.join("circle")
.attr("transform", d => `translate(${x(d)},${y()})`)
.attr("r", 3.5);
svg.append("g")
.call(xAxis);
svg.append("g")
.call(brush)
.call(brush.move, [0.3, 0.5].map(x));
function brushed({selection}) {
if (selection === null) {
circle.attr("stroke", null);
} else {
const sx = selection.map(x.invert);
circle.attr("stroke", d => sx[0] <= d && d <= sx[1] ? "red" : null);
}
d3.select(this).call(brushHandle, selection);
}
return svg.node();
}
brushHandle = (g, selection) => g
.selectAll(".handle--custom")
.data([{type: "w"}, {type: "e"}])
.join(
enter => enter.append("path")
.attr("class", "handle--custom")
.attr("fill", "#666")
.attr("fill-opacity", 0.8)
.attr("stroke", "#000")
.attr("stroke-width", 1.5)
.attr("cursor", "ew-resize")
.attr("d", arc)
)
.attr("display", selection === null ? "none" : null)
.attr("transform", selection === null ? null : (d, i) => `translate(${selection[i]},${(height + margin.top - margin.bottom) / 2})`)
arc = d3.arc()
.innerRadius(0)
.outerRadius((height - margin.top - margin.bottom) / 2)
.startAngle(0)
.endAngle((d, i) => i ? Math.PI : -Math.PI)
xAxis = g => g
.attr("transform", `translate(0,${height - margin.bottom})`)
.call(d3.axisBottom(x))
x = d3.scaleLinear([0, 1], [margin.left, width - margin.right])
y = d3.randomNormal(height / 2, height / 12)
margin = ({top: 10, right: 20, bottom: 20, left: 20})
height = 120
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.
