Series.Delete function takes too long with labels

[slvjm]

I am using TChart version 8.06 to create a real time graph. When I add the data points via AddXY, I am adding a label for each point. If the users sets up their graph to hold hundred of thousands of data points, and to delete most, or all, of those points when the graph is full, the call to the series's delete function can take a very long time. For example, if I have 500,000 points in my graph, all of which have a label, the function call "series.Delete(0, 499,999)" can take well over 50 seconds. If I do not add a label in the AddXY function, then that same function all takes about 1 millisecond.

Is this a TChart bug, or is there some kind of optimization that I should be doing?

[Sandra]

Hello slvjm,

Sorry for the delay. I have added your request in wish-list with number [TV52015622] to be consider it inclusion in future versions of TeeChartVCL. On the other hand, I think can be helpful for you, use FastLine Series, so if you use it the problem about performance disappears and the Chart is painted faster, to check it you only have change Point Series to FastLineSeries.

Thanks,

[slvjm]

For me, this happens with both the TLineSeries and the TFastLineSeries. However, the drawAllPoints property was set to true. Perhaps setting this to false makes a difference with the TFastLineSeries? I will have to experiment a bit more.

[Narcís]

Hi slvjm,

Perhaps setting this to false makes a difference with the TFastLineSeries?

Yes, for sure! DrawAllPoints feature was implemented for performance purposes. There's also DrawAllPointsStyle property which may help you find the most suitable approach to your needs.