Bug: Charts (flow) incorrect index with chart.setTimeline(true)


A bug with vaadin line charts with 50K+ of point values in:

chart = new Chart(ChartType.LINE);
(...then load 50K points of data into a series, or multiple series)
public void mouseOverFired(PointMouseOverEvent e) {
   e.getItemIndex()  and e.getItem() are incorrect for the point hovered over in the graph - 
   I will hover over what should be point 40,000 and will instead get an index returned of 
   about 1300 (depending on graph size)

The issue appears to be with the reduction of datapoints that I suspect setTimeline(true) causes to happen. The chart will only show a max index of about 1500 points (fullscreen in my browser) so I think there’s some form of reducing going on given the dataset size

If I pass < 1500 points to the linechart, everything works swimmingly. So it looks like the event index isn’t taking into account the reduction method being used.

Could this be fixed please. Kind of need correct indexes :slight_smile:

Hi, thanks for reporting. I think this issue should be added to bug tracker here: https://github.com/vaadin/vaadin-charts-flow/issues since it is not yet there.

Ah - didn’t see the bugtracker over there, I’ll do that in a moment - perhaps worth a link in the site main menu(unless I’ve missed it)

Edit: submitted - might as well delete this thread now :slight_smile: