Function drawLink

src/playground.ts:752–788

(
    input: nn.Link, node2coord: {[id: string]: {cx: number, cy: number}},
    network: nn.Node[][], container,
    isFirst: boolean, index: number, length: number)

}

function drawLink(
    input: nn.Link, node2coord: {[id: string]: {cx: number, cy: number}},
    network: nn.Node[][], container,
    isFirst: boolean, index: number, length: number) {
  let line = container.insert("path", ":first-child");
  let source = node2coord[input.source.id];
  let dest = node2coord[input.dest.id];
  let datum = {
    source: {
      y: source.cx + RECT_SIZE / 2 + 2,
      x: source.cy
    },
    target: {
      y: dest.cx - RECT_SIZE / 2,
      x: dest.cy + ((index - (length - 1) / 2) / length) * 12
    }
  };
  let diagonal = d3.svg.diagonal().projection(d => [d.y, d.x]);
  line.attr({
    "marker-start": "url(#markerArrow)",
    class: "link",
    id: "link" + input.source.id + "-" + input.dest.id,
    d: diagonal(datum, 0)
  });

  // Add an invisible thick link that will be used for
  // showing the weight value on hover.
  container.append("path")
    .attr("d", diagonal(datum, 0))
    .attr("class", "link-hover")
    .on("mouseenter", function() {
      updateHoverCard(HoverType.WEIGHT, input, d3.mouse(this));
    }).on("mouseleave", function() {
      updateHoverCard(null);
    });
  return line;
}

/**
 * Given a neural network, it asks the network for the output (prediction)