I have a sizable amount of data in a series on the igDataChart and tool tips are working well for most scenarios but there is a scenario where I believe there is a bug in the display of sudden trend changes when zoomed out.
I have over 3000 data items in my series and in one particular scenario, there is a big drop from one value of 40 down to a value of -3 in the next item. When at a fully zoomed-out level and the tooltip is displayed while hovering over the -3 point, the value 40 is displayed. When zooming in, the correct -3 tooltip value is displayed for the same point.
I think that this relates to the effect when zooming out, where many close points are grouped into one to make the display clearer. The y axis value sequence in this section of the series is 39, 39, 40, 40, -3, -3, -3. When zoomed it appears to only plot 39 and then -3 out of this sequence (which is fine) and the tool tip for 39 correctly appears. It's just the logic that determines what value to display in the grouped scenario that seems to be a little incorrect. It is only apparent because there is such a change between these two values that it became clear.
I am using an MVC AxesBuilder with a NumericYAxis and a CategoryXAxis (version 3.12.1.2059).
p.s. I haven't copied any code simply because there would be lots of code to trawl through.
Hi,
This sounds pretty similar to a bug that was addressed recently. I say bug, but its rather that the default behavior is that, for performance reasons, if a lot of values are at the same x location, it sometimes does not recalculate the y position with high fidelity to position the marker (I assume you have your mouse over the marker for the incorrect tooltip?) So some data shapes (with extremely large y drops over short periods) can have markers that don't have an appropriate data context.
To avoid making breaking changes to existing customers, and to avoid negatively affecting performance unless you have lines with this data shape, the fix for this issue is optional. You can activate it by enabling the option useHighMarkerFidelity on your series.
Unfortunately, I don't think we've had an IgniteUI serivice release since this issue was fixed, so you may need to wait for the next Service Release to have this option. If you can send me an isolated reproduction of this issue, I can check if it is resolved by this fix.
-Graham
Thanks for the info. That fix sounds like what I am looking for so will try it at the next service release.
I already tried unpicking the code to get an example but it was taking a long time isolating the relevant parts. If I have more problems when the SR comes out, I will post some code.