Begin forwarded message:
From: Chris Pelkie <[EMAIL PROTECTED]>
Date: Thu Apr 3, 2003 07:48:21 US/Eastern
To: [email protected]
Subject: Re: [opendx-users] automatic visualizing?
Let's make sure the terminology is correct: a module is one of those green boxes which represents something like a function call in a traditional language. Modules are precompiled C or C++ or whatever and are loaded when you start DX or choose Load Module Definition from the File menu.
Macros are wrappers around some number of modules (and can include other macros). They are illusions in the sense that you can, generally speaking, NOT use the wrapper and get the same effect. That is, you put a bunch of modules down and connect them, then run the net. Then you decide that particular set of modules provides a functionality that would be useful in the future (or even another copy in the same net) and don't want to have to drag all the modules out again and connect them up. So you wrap them in a macro and now you only have to place one green box (the macro) to effectively place all the set of contained and pre-connected modules. Thus, macros are NOT compiled, but run-time processed by DX just as if they were not wrapped. (Advanced DXers: I'm ignoring "scope" for the sake of this discussion).
If there are macros in the net, they look like any other module, so you are correct, it could be confusing. However once you determine that a green box is a macro, you select it and choose Windows: Open Selected Macro to reveal it's internals in another VPE (visual program editor) window. Macros can be arbitrarily nested, so you may have to repeat this to get down to the core (compiled) modules. You can't drill any lower in the UI; but of course, openDX being open, if you want to know how a (compiled) module works, you get the source code and start digging in.
To find if/what macros are in a net, you can open the .net file in a text editor. Macro names appear right up at the top of the net file, which is otherwise an unholy thing to try to read and understand. Don't worry about the apparently hard-coded paths; if you move the net and macros to another location, reset the environment variable DXMACROS to the new macro location and the net will find them next time it opens. If you save it then, the new path will be written into the net.
Yes, DX can calculate a lot of new info on the fly, using "data-driven" techniques. Thus, colors can be manufactured inside the running DX net by reading the data and making new color info; you don't need to import colors from outside. If you have imported colors, you can ignore them and have DX make new colors if you prefer.
A colormap can be set up and as different data is read in (assuming it fits into the desired range), you'd see the same color schema applied to different data.
On Wednesday, Apr 2, 2003, at 16:52 US/Eastern, Rachel V. Pollard wrote:
I'm not following a basic thing about opendx and i'm hoping someone can_______________________________
point me to the relevant literature. I have a file that successfully can
be visualixed in opendx, but i don't know how opendx makes the macros(?) it
does for the file. Doesn't this sort of thing need to be specified in the
file? If you run the file below through opendx you see lots of cool stuff
like color and lines and different fields for changing parameters in the
control panel. I know where it finds the fields in the file, but does it
automatically decide to do color and such?
The file is called grids_massbay.nc
http://puma.wellesley.edu/~rpollard/
thanks for any pointers in the right reading direction...
veera
Chris Pelkie
Scientific Visualization Producer
622 Rhodes Hall, Cornell Theory Center
Ithaca, NY 14853
