calculate the difference between 2 series in tooltip for highstock

Question

I need some help to find a solution to display the difference between the series in the tooltip.

Here <- is a simple screenshot with my problem:

how can i sol

Answer 1

Use tooltip.formatter - you have there access to the points (this.points[0], this.points[1] etc.). Just calculate different between y-values.

Note: tooltip.formatter is available only on the highest level of options, like in the API.

Demo: http://jsfiddle.net/bwefs1ak/

    tooltip: {
        formatter: function () {
            var s = '' + Highcharts.dateFormat('%A, %b %e, %Y', this.x) + '';

            $.each(this.points, function () {
                s += '
Value: ' + this.y;
            });

            s+= '
Diff: ' + ( this.points[0].y - this.points[1].y );

            return s;
        }
    },