multi_line_chart = {
const svg = d3.select(DOM.svg(width, height));
svg.append("g")
.call(xAxis);
svg.append("g")
.call(yAxis);
const path = svg.append("g")
.attr("fill", "none")
.attr("stroke", "steelblue")
.attr("stroke-width", 1.5)
.attr("stroke-linejoin", "round")
.attr("stroke-linecap", "round")
.selectAll("path")
.data(data.series)
.enter().append("path")
.style("mix-blend-mode", "multiply")
.attr("d", d => line(d.values));
svg.append("text")
.attr("id","title")
.attr("x", (width / 2))
.attr("y", (20))
.attr("text-anchor", "middle")
.style("font-size", "20px")
.text("Migration Change for all the countries from 1962 to 2017 ");
svg.call(hover, path);
return svg.node();
}
function hover(svg, path) {
svg
.style("position", "relative");
if ("ontouchstart" in document) svg
.style("-webkit-tap-highlight-color", "transparent")
.on("touchmove", moved)
.on("touchstart", entered)
.on("touchend", left)
else svg
.on("mousemove", moved)
.on("mouseenter", entered)
.on("mouseleave", left);
const dot = svg.append("g")
.attr("display", "none");
dot.append("circle")
.attr("r", 2.5);
dot.append("text")
.style("font", "10px sans-serif")
.attr("text-anchor", "middle")
.attr("y", -8);
function moved() {
d3.event.preventDefault();
const ym = y.invert(d3.event.layerY);
const xm = x.invert(d3.event.layerX);
const i1 = d3.bisectLeft(data.dates, xm, 1);
const i0 = i1 - 1;
const i = xm - data.dates[i0] > data.dates[i1] - xm ? i1 : i0;
const s = data.series.reduce((a, b) => Math.abs(a.values[i] - ym) < Math.abs(b.values[i] - ym) ? a : b);
path.attr("stroke", d => d === s ? null : "#ddd").filter(d => d === s).raise();
dot.attr("transform", `translate(${x(data.dates[i])},${y(s.values[i])})`);
dot.select("text").text(s.name);
}
function entered() {
path.style("mix-blend-mode", null).attr("stroke", "#ddd");
dot.attr("display", null);
}
function left() {
path.style("mix-blend-mode", "multiply").attr("stroke", null);
dot.attr("display", "none");
}
}
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.
