How can I force highcharts to show every x-axis label regardless of spacing constraints?

Question

I'd like to show every x-axis label, and you can see it's only showing every other one:

http://jsfiddle.net/f48cjf01/2/

The relevant code:

xAxis: {
    categories: _.pluck(_mainData, "number")
    , labels: {
         rotation: 290
         , step: 1 //show every tick regardless of spacing
         , align: 'right'
    }
}

What do I need to do to show every tick? (I know it may look ugly here considering how little space there is...but I'd like to force it nonetheless)

Answer 1

One solution is to use a tickPositioner function and specify every single index:

xAxis: {
    tickPositioner: function() {
        var result = [];
        for(i = 0; i < _mainData.length; i++)
            result.push(i);
        return result;
    }
}

See this JSFiddle example. You can remove xAxis.labels.step when using this.

At first tickInterval looks easier, but unfortunately doesn't work because of the following note:

If the tickInterval is too dense for labels to be drawn, Highcharts may remove ticks.