Re: questions on functionalities of VisAD X-Y style 2D plots

Hi-

m huang wrote:
Hi

Sorry to pile on so many questions. I appreciate people,
particularly Bill, to take time to answer. I will reply
the answers after finish this round.
I would like to know in X-Y style 2D plots
1) Can VisAD set line styles (continuous, dotted, dashed,
dotted-dashed...)? If yes, how do I find out existing choices
of line styles.

You can call GraphicsModeControl.setLineStyle() to set these
globally, or you can add a ConstantMap with your DataReference
to Display.LineStyle.  This is a pretty recent addition so
it is not in the tutorials/docs yet.  See javadoc for
GraphicsModeControl for available types.

2) Is there an *existing* set of shapes for the user to use
as data points in the plot? I see there is support for creating
any shapes and there is an example as how to do this for those
who want to make a shape from scratch. I have tinkered with
the tutorial example P2_06 and tried to map the example realTypes
into Display.Shape, but I don't see anything showing up.

There is no existing one other than those in
visad.meteorology.WeatherSymbols.  There are some defined int
the jython stuff.  Tom W. could point you to those.  We have some
in our IDV, and it would be useful to move these into core visad
at some point.

3) Does visAD support legend of data points and line types?
Or the user need to make a legend from scratch?

You would need to create this.  The Australian Bureau of
Meteorology has done some work on this I think.

4) how to change the plotting box aspect ratio without
changing other components? The Display.setProjectionControl()
"streches" or "compresses" all component being drawn. This
is not what I ask for. What I ask for for example, is
how to change the aspect of the box without changing the width
of the ticks, data curves, font and any other thing on the plot.

For graphs that use Display.XAxis, Display.YAxis and Display.ZAxis,
use ProjectionControl.setAspectCartesian().

5) If the user want to change the default mouse behavior
in VisAD plots, generally how is this done?

See the javadoc for MouseHelper.setFunctionMap().  Use
DisplayRenderer.getMouseBehavior().getMouseHelper().

Also, as you try to spin up on VisAD, don't forget to
search the list archives for answers to some of your questions:

http://www.unidata.ucar.edu/glimpsedocs/ghvisad.html

A search on "mouse button" turned up how to do 5, a search
on "line style" turned up the answer to 1, a search for
"aspect ratio" turned up the answer to 4.

I would chime in on why you should use VisAD, but am sorely
pressed for time with an upcoming conference (AGU) to prepare for
where I'll be highlighting Unidata's IDV which is built on
VisAD.  If VisAD does not have what you need, you can add
it yourself, or fund SSEC to make enhancements (we do both).


Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
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