Hi,
If you mean drawing ellipses at data point locations, you might try adding a BubbleRenderer to chart's Plot, however BubbleRenderer draws circles with same X/Y radius. If you need different X/Y radii, you might have to create a custom series renderer, e.g. here's BubbleRenderer drawing code you could adapt for your scenario:
protected internal override void Draw(RenderContext context)
{
EnumVisiblePoints(context, (s, i, point) =>
{
var d = (float)Series[s].GetValue(i, 2) * 2;
using (var brush = EffectiveFill(s, i, context).CreateGdiBrush(new RectangleF(point.X - d / 2, point.Y - d / 2, d, d)))
context.Graphics.FillEllipse(brush, point.X - d / 2, point.Y - d / 2, d, d);
using (var pen = EffectiveStrokePen(s, i, context).CreateGdiPen())
context.Graphics.DrawEllipse(pen, point.X - d / 2, point.Y - d / 2, d, d);
...
}
If that ellipse of yours shows some cumulative / mean value derived from main series data, you could represent it as a separate series containing a single data point.
Regards,
Slavcho
Mindfusion