ChartEx is a WinForms Chart wrapper which optimizes rendering of huge portions of data.

ChartEx optimizes displaying of huge portions of data on a single Chart Control from .NET WinForms Framework. While simple Chart doesn't allow threading it will take some time for Chart to render huge portions of data, ChartEx wraps the Chart and efficiently solves the problem.

ChartEx utilized all data management and provides a way to specify one of the predefined or custom data approximation algorithms. The key for this problem was to reduce amount of points to be rendered (since points were lose too each other and most of them were rendered on the top of each other which is redundant). These algorithms determines major and minor data array peeks and renders on the Chart only major points. Furthermore, it behaves in the same way when scaling the Chart: if there are still lots of points ChartEx will apply approximation to the scaled area.

  Chart chart = new Chart();
  ChartEx chartEx = new ChartEx(chart);

Approximation algorithm is provided by IChartExSelector interface.

  chartEx.SelectionMethod = new MyApproximationSelector();

You can set either predefined selector or create your own.

a) ChartEx comes with predefined IChartExSelector's:

• ChartExSimpleSelector - Evenly selects points; (default selector)
• ChartExPeekSelector - Selects stationary points;
• ChartExDeltaPeekSelector - Selects stationary points which have delta between two consecutive points greater than specified threshold value;
• ChartExSavitzkyGolaySelector - Selects points using Savitzky–Golay filter;

b) To create custom selector you have to implement IChartExSelector. Example:

  class ChartExSimpleSelector : IChartExSelector
  {
    private int GetStep(int amountOfPoints, int maxRenderedPoints)
    {
        return (int)Math.Ceiling((double)amountOfPoints / maxRenderedPoints);
    }

    public List<PointF> Select(List<PointF> candidatePoints, int maxPoints)
    {
        List<PointF> resultPoints = new List<PointF>();
        int step = GetStep(candidatePoints.Count, maxPoints);
        for (int i = 0; i < candidatePoints.Count; i += step)
            resultPoints.Add(candidatePoints[i]);
        return resultPoints;
    }
  }

• You can create SeriesEx as you usually do with regular Series

  SeriesEx seriesEx = new SeriesEx("Name"); // SeriesEx wraps regular Series.

• Or wrap an existing series

  Series series = new Series("Regular");
  SeriesEx seriesEx = new SeriesEx(series);

• Add created seriesEx

  chartEx.Series.Add(seriesEx);

Points added through Add method of the regular series will not be observable and therefore ChartEx won't refresh approximation.

Since ChartEx and SeriesEx were designed as wrappers you are able to access their wrapped objects by WrappedChart and WrappedSeries respectivelyю

For example, change series ChartType to line:

  seriesEx.WrappedSeries.ChartType = SeriesChartType.Line;

Or set range of chart's X-axis:

  chartEx.WrappedChart.ChartAreas[0].AxisX.Minimum = 0;
  chartEx.WrappedChart.ChartAreas[0].AxisX.Maximum = 100;