1 It seems nice to be able to create a one-stop visualisation of a container, for example: std::vector<double> my_data_structure; // fill with my data... my-graph << my_data_structure; // But should the myriad of graph plotting *options* be set using operator << allowing them to be chained together thus my_graph << line_color(black) << point_color(blue) << x_range(-10, 10) << y_range(0, 5)...; as suggested by John Maddock (who has a most irritating habit of being right ;-) or more conventional setter member functions my_graph.line_color(black); my_graph.point_color(blue); my_graph.x_range(-10, 10); my_graph.y_range(0, 5); and could getter versions return their current values if (my_graph.line_color() == black) .... possibly chained (return this) to reduce typing? http://www.parashift.com/c++-faq-lite/references.html#faq-8.4 my_graph.line_color(black).point_color(blue).x_range(-10, 10).y_range(0, 5); 2 How can a set of plot settings be 'saved' for repeated use? Once one has chosen a plot style, line_color black, point_color blue ..., one wants to save this for re-use (though things like the range may change). 3 Does anyone have experience with auto-axis scaling algorithms. The best reference I have found is Michael Bramley, C/C++ Users journal, www.cuj.com July 2000, pp 20 - 26 But this does not always give the nicest scales - it would work nicely using decimal, but the damned binary FP *wrong* bits at the end screw up the comparisons. (Excel plots show this behaviour). Suggestions? Paul --- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB +44 1539561830 & SMS, Mobile +44 7714 330204 & SMS pbristow@hetp.u-net.com