dygraph改变线条颜色

Question

I want to change line color off a dygraph chart with value.
Example when my data is greater than 2, I want to change the color.

I try option color, but is change just the point color.

I make a JsFiddle here .

This is my option dygraph:

color: function (color, d) {
    if (typeof d.index === 'undefined') { return color; }

    var val = columns[0][d.index + 1];

    if (val >= 0 && val <= 150) {
        color = 'green';
    } else if (val > 150 && val <= 300) {
        color = 'yellow';
    } else if (val > 300) {
        color = 'red';
    }

    return color;
}

Answer 1

As you've discovered, you can't set color to a function. You can use the slightly more general drawPointCallback option , though, which lets you draw any shape with any color for each point:

function coloredCircle(g, series, ctx, cx, cy, color, radius, idx) {
  var y = g.getValue(idx, 1);
  var pointColor = y < 5 ? 'green' : 'blue';
  ctx.save();
  ctx.fillStyle = pointColor;
  ctx.beginPath();
  ctx.arc(cx, cy, radius, 2 * Math.PI, false);
  ctx.closePath();
  ctx.fill();
}

g = new Dygraph(
    div, data,
    {
      series: {
        Y: {
          drawPointCallback: coloredCircle,
          pointSize: 5,
          drawPoints: true
        }
      }
    });

Here's a fully-worked fiddle . See the custom-circles demo for more examples of drawPointCallback .