Re: labels in charts?

Stephen Langer (
Tue, 18 Feb 1997 10:27:46 -0500

To subscribers of the xforms list from "Stephen Langer" <> :

> To subscribers of the xforms list from "Dr. T.C. Zhao"
<> :
> From: "Stephen Langer" <>
> > I'm trying to label points on an FL_LINE_CHART. Actually, I just want to
> >highlight one particular point, so I used
> > fl_add_chart_value(obj, val, "@square", FL_BLACK);
> ...
> I've fixed this. While doing this, I also added
> fl_set_chart_l{size|style|colr} to manipulate the
> item label attributes.
Thanks! That will be a great help.

What I'd really like to have is an interactive strip chart, where I
can click on a point and mark it, and the mark will move with the point
as new data are added to the chart. I could do this with an XYPlot object,
but then I'd have to reload the whole data set when I want the chart to
scroll. It would be simpler to put a free object on top of the chart. The
free object would intercept the mouse clicks. The difficulty would be in
converting from screen coordinates to chart coordinates -- the curve on
the line chart doesn't go from edge to edge, so it's not obvious how the
x coordinate of a mouse click corresponds to the chart data.

Any suggestions?
-- Steve

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