Re: Object graphic 3d Scatterplot

["Mark Hadfield" <m.hadfield(at)niwa.cri.nz>]

"Ben Tupper" <tupper@seadas.bigelow.org> wrote in message
news:38D90B6F.8F9377D7@seadas.bigelow.org...
> Martin Schultz wrote:
>
> > just an unsolicited question: wouldn't this be a good example for a new
> > subclass of IDLgrPlot? You could extend the object definition by a new
> > property (a pointer to an array DataClass for example) modify the
> > SetProperty and GetProperty methods to allow changing/retrieving the
> > DataClass values and change the Show (or whatever) method to use the
> > DataClass values as a color coding for example. In pseudo code this
> > would be something like:
>
> It sounds like a good idea... but way over my head.   I wonder if Mark
> Hadfield's MGHgrGraph already handles kind of a thing?

Some of the stuff I put in MGHgrGraph is way over my head too! But no, it
doesn't do anything like what Martin is suggesting. An MGHgrGraph is a form
of IDLgrView, and its methods are mostly concerned with fitting new graphics
atoms into a view: putting them in the right model, associating them with
axes, setting the scaling, applying fonts etc.

I've been following this thread with interest, but not very closely, and
don't have much to add, only to note that I have experimented with
subclassing graphics atoms' Draw methods and found that you can make an atom
look like anything you want. E.g. class MGHgrGLaxis

http://katipo.niwa.cri.nz/~hadfield/gust/software/idl/mghgrglaxis__define.pr
o

which hides an axis's labels on each Draw and substitutes its own.

It would be easy, for example, to create a symbol object that appeared in a
different colour every time it was drawn. However the problem in applying
this to the present problem is that this "smart symbol" would have to know
which data point it is associated with on each Draw, and I don't think there
would be any way of passing this information to it.

---
Mark Hadfield
m.hadfield@niwa.cri.nz  http://katipo.niwa.cri.nz/~hadfield/
National Institute for Water and Atmospheric Research
PO Box 14-901, Wellington, New Zealand