or (var hl = 0; hl < chartOptions.horizontalLines.length; hl++) {
        var line = chartOptions.horizontalLines[hl],
            hly = Math.round(valueToYPixel(line.value)) - 0.5;
        context.strokeStyle = line.color || '#ffffff';
        context.lineWidth = line.lineWidth || 1;
        context.beginPath();
        context.moveTo(0, hly);
        context.lineTo(dimensions.width, hly);
        context.stroke();
        context.closePath();
      }
    }

    // For each data set...
    for (var d = 0; 