Hi Nicolas,

Thank you for your interest in Telerik UI for Maui Chart control. 

I have reviewed the feedback and let me share more details on it:

When hundreds of data points are added and chart control has to generate runtime several elements for each one of those points, which amounts to thousands/millions of objects in the visual tree, then some delays are expected. Additionally, having so many items in an ObservableCollection at once on a mobile device is another problem.

Here are some approaches you can try to speed up the performance:

Approach 1) -> if you want to show thousands of points, I will suggest you implement sampling. This is when you aggregate lots of items (thousands) into less items (hundreds). I suggest this mainly because if you have more items horizontally than pixels, this means that a few items may be drawn in very close proximity (near the same pixel) which will lead to an unreadable visualization, and likely a slow initial load.

Sampling approach: 

private ObservableCollection<NumericalData> GetNumericData2()
        {
            var originalData = this.Data;
            var chartData = new ObservableCollection<NumericalData>();

            for (int i = 0; i < originalData.Count; i++)
            {
                if (i % 5 == 0)
                {
                    chartData.Add(originalData[i]);
                }
            }
            return chartData;
        }

I have attached the xaml and code behind files of this approach.

You can tweak that number to suit your needs or you can research online if you want a more precise sampling formula if that one doesn't fit your needs.

Approach 2) -> Live update: You can add data points to the chart dynamically, so for example you can load the first 500 points then remove these points and add another 500 points. 

Of course, the Chart is still in a preview stage and we will have your feedback in mind. 

Let me know if I can assist with anything else.

Regards,
Didi
Progress Telerik