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

maohai-

m huang wrote:
--- Don Murray <dmurray@xxxxxxxxxxxxxxxx> wrote:

thanks, Don. I have been wondering what all these methods
with no JavaDoc at all do, setAspectCartesian(), GraphicsModeControlJ2D.getCurvedSize(), getPolygonMode() ...

I actually just updated the javadocs for GraphicsModeControlJ*D.
Like I said before, if I touch a class, I try to add javadocs.
You'll get no argument from me that they could be better, but
as I said before, anyone who wants to volunteer to do so is
welcome.  My approach is to add it as time permits.  This may
not satisfy your needs today.

by the way, I am now most puzzled by the ScreenBasedMode
of the scale, from the example (e.g. 42), it looks like
it is not the scale that is stationary to the screen, but
the coordinate system that the scales reflects. Is this
correct?

I didn't write the screenBasedMode scale stuff, so I don't
really know how it works or it's purpose.  Bill would have
to answer this.


Yes it is a great tool. But I often heasitate in using the search
result because apparently some suggested code fixes have since been implemented in the release, so in general I don't know how
relevant the information in the archive is compared to the current
release.

But it's a first place to look.  Many time, the search will
show entries that say the code has been fixed.

thanks for taking time to answer. Does VisAD have a SPR/SCR
(Software Problem Report and Software Change Request) system
where one can see a list of change request listed?

Just the list.  One thing to keep in mind is that VisAD is
not an application, but a library upon which specialized
applications (with simpler interfaces even) can be built.
As Bill said in his previous note, it is the only system
that integrates many of the desirable features in a
scientific system - data model that handles metadata (units,
coordinate transforms, etc) and a display model that permits
almost any type of display.  You can use other systems
(the units packages you cited, SGT), but they you have to
write a lot of code to pull them all together.  The units
is a perfect example. In many other systems, you just pass
an array of values to the plotting package and it's up to
you to define the units.  If you want to do calculations
on these arrays and they have different units, you'll have
to be the one to keep track of it all.  Are those distances
in miles or km?  Are those temperatures in K or C?  VisAD
handles all this for you (and allows you to display the
data in any compatible unit!)  Documentation issues aside,
its a very powerful system.

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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