Function area

d3-3.2.8/d3.js:7229–7250

(data)

  function d3_svg_area(projection) {
    var x0 = d3_svg_lineX, x1 = d3_svg_lineX, y0 = 0, y1 = d3_svg_lineY, defined = d3_true, interpolate = d3_svg_lineLinear, interpolateKey = interpolate.key, interpolateReverse = interpolate, L = "L", tension = .7;
    function area(data) {
      var segments = [], points0 = [], points1 = [], i = -1, n = data.length, d, fx0 = d3_functor(x0), fy0 = d3_functor(y0), fx1 = x0 === x1 ? function() {
        return x;
      } : d3_functor(x1), fy1 = y0 === y1 ? function() {
        return y;
      } : d3_functor(y1), x, y;
      function segment() {
        segments.push("M", interpolate(projection(points1), tension), L, interpolateReverse(projection(points0.reverse()), tension), "Z");
      }
      while (++i < n) {
        if (defined.call(this, d = data[i], i)) {
          points0.push([ x = +fx0.call(this, d, i), y = +fy0.call(this, d, i) ]);
          points1.push([ +fx1.call(this, d, i), +fy1.call(this, d, i) ]);
        } else if (points0.length) {
          segment();
          points0 = [];
          points1 = [];
        }
      }
      if (points0.length) segment();
      return segments.length ? segments.join("") : null;
    }
    area.x = function(_) {
      if (!arguments.length) return x1;
      x0 = x1 = _;