Zoomable Area

<!DOCTYPE html>
<svg width="960" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>

var svg = d3.select("svg"),
    margin = {top: 20, right: 20, bottom: 30, left: 60},
    width = +svg.attr("width") - margin.left - margin.right,
    height = +svg.attr("height") - margin.top - margin.bottom,
    g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var parseDate = d3.timeParse("%Y-%m-%d"),
    formatDate = d3.timeFormat("%Y");

var x = d3.scaleTime()
    .domain([new Date(1999, 0, 1), new Date(2003, 0, 0)])
    .range([0, width]);

var y = d3.scaleLinear()
    .range([height, 0]);

var xAxis = d3.axisBottom(x);

var yAxis = d3.axisLeft(y);

var area = d3.area()
    .curve(d3.curveStepAfter)
    .y0(y(0))
    .y1(function(d) { return y(d.value); });

var areaPath = g.append("path")
    .attr("clip-path", "url(#clip)")
    .attr("fill", "steelblue");

var yGroup = g.append("g");

var xGroup = g.append("g")
    .attr("transform", "translate(0," + height + ")");

var zoom = d3.zoom()
    .scaleExtent([1 / 4, 8])
    .translateExtent([[-width, -Infinity], [2 * width, Infinity]])
    .on("zoom", zoomed);

var zoomRect = svg.append("rect")
    .attr("width", width)
    .attr("height", height)
    .attr("fill", "none")
    .attr("pointer-events", "all")
    .call(zoom);

g.append("clipPath")
    .attr("id", "clip")
  .append("rect")
    .attr("width", width)
    .attr("height", height);

d3.csv("flights.csv", function(d) {
  d.date = parseDate(d.date);
  d.value = +d.value;
  return d;
}, function(error, data) {
  if (error) throw error;
  var xExtent = d3.extent(data, function(d) { return d.date; });
  zoom.translateExtent([[x(xExtent[0]), -Infinity], [x(xExtent[1]), Infinity]])
  y.domain([0, d3.max(data, function(d) { return d.value; })]);
  yGroup.call(yAxis).select(".domain").remove();
  areaPath.datum(data);
  zoomRect.call(zoom.transform, d3.zoomIdentity);
});

function zoomed() {
  var xz = d3.event.transform.rescaleX(x);
  xGroup.call(xAxis.scale(xz));
  areaPath.attr("d", area.x(function(d) { return xz(d.date); }));
}

</script>

https://d3js.org/d3.v4.min.js