Small Multiples Area Chart

Small multiples of area charts for technology stock prices. Uses google finance data.

<!DOCTYPE html>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>

var smallMultipleSize = [220, 150];
  
var margin = {top: 30, right: 10, bottom: 30, left: 40},
    width = +smallMultipleSize[0] - margin.left - margin.right,
    height = +smallMultipleSize[1] - margin.top - margin.bottom;

// parse day, abbreviated month name, year without century
var parseTime = d3.timeParse("%d-%b-%y");

var x = d3.scaleTime()
    .rangeRound([0, width]);

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

// areas are defined by two bounding lines - here the x value is the same for both
// the y values, y0 and y1 differ
// see https://github.com/d3/d3-shape#areas for API reference
var area = d3.area()
    .x(function(d) { return x(d.Date); })
    .y1(function(d) { return y(d.Close); })
// the bottom coordinate of the area will always be zero
  	.y0(y(0));

// Add a line to give only the top of the area a stroke
var line = d3.line()
		.x(function(d) { return x(d.Date); })
		.y(function(d) { return y(d.Close); });

var svg = d3.select("body").append("svg")
      .attr("width", smallMultipleSize[0])
      .attr("height", smallMultipleSize[1])
      .append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");

svg.append("path")
        .datum(data)
        .attr("fill", function() {
      		for (var i in stocks) {
            if (stocks[i].name === name) {
              return stocks[i].colour;
            }
          }
         })
        .attr("d", area);

// add line to top of area
    svg.append("path")
      .datum(data)
      .attr("fill", "none")
      .attr("stroke", "black")
      .attr("d", line)

// add line to the right of the area
    svg.append("line")
      .attr("x1", x.range()[1])
      .attr("y1", 0)
      .attr("x2", x.range()[1])
      .attr("y2", y.range()[0])
      .attr("fill", "none")
      .attr("stroke", "black")

svg.append("g")
        .attr("transform", "translate(0," + height + ")")
        .call(d3.axisBottom(x).ticks(3))

svg.append("g")
        .call(d3.axisLeft(y).tickSizeOuter(0).ticks(2))
      .append("text")
        .attr("fill", "#000")
        .attr("y", 6)
        .attr("x", 0)
        .attr("dx", "0.71em")
        .attr("text-anchor", "start")
        .text("Price ($)");

// Add a small label for the symbol name.
    svg.append("text")
        .attr("x", width -6)
        .attr("y", height -6)
        .style("text-anchor", "end")
        .style("font-family", "sans-serif")
        .style("font-size", "12")
        .text(name.toUpperCase());
}

</script>

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