How to Setup IDL and X-windows at PPPL

General Information

Although you may run IDL from a non-X terminal (like puTTY), most applications need X-windows. This comes with X11 on a mac. Many PPPL PC users use Exceed, a commercial product, but you can download shareware Xming and puTTY from the web. Be sure to check "X-11 forwarding" when using puTTY.

To use IDL from X windows, first setup IDL in system-specific ways (see below).

type "idl" (without quotes) at the system prompt in any xterm window.

Setup Details

On the PPPL Linux cluster, type the following, or include in your startup file:

	module load idl

Some window managers automatically set this information, but if not, you can do it manually. You will need to know your computers TCP/IP number, e.g., 198.35.2.251, or the name, such as mything.pppl.gov. See the architecture-specific information below. Additionally, most X-window systems (but not MacX and eXodus) need permission to send their X windows to your X display. For example, if you have logged into a portal machine to run IDL, you will have to type

	ssh portal.pppl.gov

in a login window, or give permission through some security menu, to allow X windows from portal.pppl.gov to be displayed at your display. Mac users should type " -Y" after "ssh".

On the PPPL UNIX Cluster

IDL is on several UNIX computers at PPPL. General UNIX users should use portal. NSTX users should use nstxpool (you must be in the unix group "nstx" to log into nstxpool computers).

IDL will be in your path, so simply type idl to the system prompt.

NSTX users new to Unix should read $NSTXUSR/util/init_files/AAA_Whats_Here.txt.

To have access to NSTX-support (and some other user-written routines), you will need additional directories added to your IDL_PATH environmental variable. If you are running the csh, tcsh or bash shells, place the following in your .cshrc UNIX startup file:

     module load nstx

Frequently Asked Questions

How can I keep the colors from flashing on my X-display when I change focus to different windows?
You have some options. See Limiting "Flashing" when using IDL at PPPL.
Why are all my colors very dark/really off, etc.?
Your monitor, or X-server, is probably set for 24-bit color (millions of colors), and the IDL routines are trying to work with 8-bit color. Do the following immediately upon entering IDL:
```
     IDL> Device, Decomposed=0
```
See http://NSTX.pppl.gov/nstx/Software/IDL/simplecolors.html for an easy way to plot with named colors in IDL. Excellent advice on using color in IDL is provided at Fanning Consulting IDL Pages . The page on Limiting "Flashing" when using IDL at PPPL is also relevant.

Documentation

Hardcopy of the IDL documentation can be purchased from ITTVis but you may actually prefer the online documentation supplied with IDL. If you are running X-windows, simply type "?" at the IDL prompt. This documentation can also be viewed from a macintosh without an IDL license -- the files may be downloaded from the PPPL Public Mac Area) (contact the help desk). Documentation sets are available in various locations around the lab. Sets may ordered from ITTVis at 303-786-9900.

If the IDL documention convention has been followed, you may get documentation on individual routines by typing:

        IDL> doc_library,'routine_name'

Please mail comments on this page to bdavis.