dumping graph

[Ginger Booth]

Hi, guys,
    Quick question:  how hard is it to get my points back out of a
BLTGraph?  Looking at BLTGraph.m, we've got:

    -addX: (double) x Y: (double) y {
    [globalTkInterp eval: "%s element append %s { %g %g };",
                    [ownerGraph getWidgetName], name, x, y];
    return self;
    }
    
    -resetData {
    [globalTkInterp eval: "%s element configure %s -data { };",
                    [ownerGraph getWidgetName], name];
    return self;
    }

And I want something like 

    -getDataI: (int) i X: (double*) x Y: (double*) y;

Or a pointer to an array of points, if there's an array of points, or
whatever.   

    I've got a TraceGraph (one of my gizmos--population or biomass) with 
a collection of lines (GraphElement **lines) and I want to dump the traces
to a file for external analysis.

Thanks,
    Ginger
    
P.S. (Yeah, I saw the reference to the golden ratio.  :) :) :)