void size_and fill_from_col()
{
	Worksheet wks = Project.ActiveLayer();  // get worksheet with group.dat data	
	DataRange dr;
	dr.Add(wks, 0, "X");
	dr.Add(wks, 1, "Y");
	
	GraphPage gp;
	gp.Create("scatter");  // create scatter graph	
	GraphLayer gl = gp.Layers(0);
	int nPlot = gl.AddPlot(dr, IDM_PLOT_SCATTER);  // add plot to layer
	gl.Rescale();

	DataPlot dp = gl.DataPlots(nPlot);
	dp.SetProp("symbol.kind", 2);//circle
	//from 1 col on the right of Y, col(C)
	double vv;LT_evaluate("modifier(1)",&vv);
	int nModi = (int)vv;
	dp.SetProp("symbol.size", nModi);//size 
	dp.SetProp("symbol.SizeFactor", 30);
	//from 2 col on the right of Y, col(D)
	LT_evaluate("modifier(2)",&vv);
	nModi = (int)vv;
	dp.SetProp("symbol.interior", nModi);//1=close, 2=open
}