/**#
		Plot a Matrix into a graph layer
	Parameters:
		matObj = Matrix data object
		nPlotID = the internal Origin plot type id..
	Return:
		0-offset data plot index of the dataplot added or -1 for error
	Example:
		void plot_matrix(string strName="Matrix1", int nPlotID = IDM_PLOT_SURFACE_WIREFRAME)
		{
			GraphPage gp;
			
			gp.Create("Wirefrm");
			
			GraphLayer glay = gp.Layers();
			
			MatrixLayer mlayer(strName);
			MatrixObject mobj = mlayer.MatrixObjects();
			
			int nPlot = glay.AddPlot(mobj, nPlotID);
			glay.Rescale();
		}
	*/
	int	AddPlot(MatrixObject& matObj, int nPlotID = IDM_PLOT_MATRIX_IMAGE);