Question

I have created some simple charts (of type FastLine) with MSChart and update them with live data, like below:

To do so, I bind an observable collection of a custom type to the chart like so:

                // set chart data source
            this._Chart.DataSource = value; //is of type ObservableCollection<SpectrumLevels>

            //define x and y value members for each series
            this._Chart.Series[0].XValueMember = "Index";
            this._Chart.Series[1].XValueMember = "Index";
            this._Chart.Series[0].YValueMembers = "Channel0Level";
            this._Chart.Series[1].YValueMembers = "Channel1Level";

            // bind data to chart
            this._Chart.DataBind(); //lasts 1.5 seconds for 8000 points per series

At each refresh, the dataset completely changes, it is not a scrolling update!

With a profiler I have found that the DataBind() call takes about 1.5 seconds. The other calls are negligible.

How can I make this faster?

• Should I use another type than ObservableCollection? An array probably?
• Should I use another form of data binding?
• Is there some tweak for the MSChart that I may have missed?
• Should I use a sparsed set of date, having one value per pixel only?
• Have I simply reached the performance limit of MSCharts?

From the type of the application to keep it “fluent”, we should have multiple refreshes per second.

Thanks for any hints!

EDIT: Solution as proposed by leppie:

                this._Chart.Series[0].Points.Clear();
            foreach (var item in value) //iterates over the list of custom objects
            {
                    this._Chart.Series[0].Points.Add(new DataPoint
                    {
                        XValue = item.Index,
                        YValues = new double[] { item.Channel0Level.Value }
                    });

            }

This now works more than twice as fast!

Answer 1

Use the other Bind methods, they are very fast.

I update about 15 series over 3 areas, with 300 points in every series, every second, and no real slow down.