labelInterpolationFnc - how to get length of series to skip x-axis labels sometimes?

Hello there,

since I sometimes have charts with lots of data points. Preferable I would like to be able to only skip the label not the actual data point but as far as my research has brought through Chartist does not support this yet.

So my workaround would be to only skip values for charts where there are too many, for example if I have over 60 labels. So I though I’d do something like this:

    var data = {
       // A labels array that can contain any sort of values
       labels: jsonResponse.labels,
       // Our series array that contains series objects or in this case series data arrays
       series: [ jsonResponse.series ]
   };
[...]
      labelInterpolationFnc: function skipLabels(value, index, data) {
           if(data.series.length > 60)
               return index % 1.5  === 0 ? value : null;
           else
               return value;
     }

But it does not work.

Any idea how that could work? 😃

Thank you Andreas

[gionkunz]

sorry, the labelInterpolationFnc is actually expected to accept 3 parameters (value, index, labels). So you can do:

labelInterpolationFnc: function skipLabels(value, index, labels) {
  if(labels.length > 60) {
    return index % 2  === 0 ? value : null;
  } else {
    return value;
  }
}

[Grovkillen]

I did something like this to make it more dynamic in my use case:

  axisX: {
	labelInterpolationFnc: function skipLabels(value, index, labels) {
	  let labelScale = Math.round( ( labels.length + 60 ) / 30 );
	  if(labels.length > 20) {
		return index % labelScale  === 0 ? value : null;
	  } else {
		return value;
	  }
	}
  }