private LineAndMarker<ElementMarkerPointsGraph> AppendLineGraph(TwoDimensionViewPointCollection collection, Pen pen, string description)
{
CircleElementPointMarker pointMaker = new CircleElementPointMarker();
pointMaker.Size = 3;
pointMaker.Brush = Brushes.Yellow;
pointMaker.Fill = Brushes.Purple;
var v = new EnumerableDataSource<TwoDimensionViewPoint>(collection);
v.SetXMapping(x => x.TimeStamp);
v.SetYMapping(y => y.Value);
return chart.AddLineGraph(v, pen, pointMaker, new PenDescription(description));
}