Interactive Data Language (IDL)
IDL Support at UVa
What is IDL?
IDL, the Interactive Data Language, is software for data analysis, visualization, and cross-platform application development. IDL combines tools for projects ranging from "quick-look," interactive analysis and display to large-scale commercial programming projects in an easy-to-use, fully extensible environment.
The IDL software may be used by faculty, staff and/or students on UVa-owned hardware connected to the UVa network (on-Grounds or through an ISP using the VPN client) for the purpose of teaching, research and administration. It may not be installed on personally-owned computers, i.e., student laptops or home computers. However, it may be used on the UVa Hive when accessed from a personally-owned computer.
IDL Availability
The University has 50 floating network licenses for IDL on the following platforms: Windows (version 7.1.1), Macintosh (7.1.1), and UNIX/Linux (7.0). In addition to the standard IDL environment functionality, the University has 10 floating network licenses for the IDL Wavelet Toolkit on the same platforms.
Users off-Grounds must be connected to the Internet and authenticated to the UVa network using either the UVa Anywhere VPN client (Windows or Mac OS X) or ssh tunneling (Linux or other UNIX) so that a continual connection is maintained with the license server/manager on ITS's UNIX Server. For ssh tunneling, you will need the port numbers from the ITS software licensing database.
Getting Started with IDL
Access from UNIX Platforms | Access from Windows | Access From Macs
Access From UNIX Platforms
1. The filesystem /common should be mounted from the UNIX server jeeves.itc.virginia.edu to the UNIX platforms that you are logged into. This is done by default on all ITS maintained UNIX machines. We recommend that on-Grounds Linux users mount licensed software over NFS. The extra time required to start the program over the network is inconsequential, and once the executable is read into the local machine's memory, it runs at the same speed as if it were installed locally. ITS provides instructions for mounting from jeeves at http://its.virginia.edu/os/linux/mount.html. If the Linux machine has the firewall enabled, as most do, then add the following line
-A UVAfw -s 128.143.2.26/32 -j ACCEPT
near the end of your iptables configuration file (/etc/sysconfig/iptables on RedHat and Fedora systems). This line tells the firewall to accept all packets from jeeves. ITS's recommended iptables configuration is described at http://its.virginia.edu/unix/sec/linux-iptables.html. Note that when you make changes to the iptables configuration file, you must either restart iptables or reboot.
IDL can also be installed locally on a UNIX machine instead of mounting the filesystem from the UNIX server, although the local copy would still have to communicate with the IDL license manager server. Users wishing to install IDL locally on any of the unsupported UNIX platforms listed above should go to the Alderman library to obtain a free copy on CDROM. For installation instructions, please refer to the appropriate section for UNIX in the Installation Guide (PDF). The required license.dat file can be downloaded from the licensing database. Your system must communicate with the license manager specified in the license.dat file in order for the full functionality of IDL to be available. In order to do this from off Grounds, it will be necessary to use ssh tunneling.
You should have the full license file downloaded to your computer before you begin the installation. We recommend that when you complete the installation, you should copy the license.dat file to some name such as license.full, then edit the license.dat file. Find the lines beginning SERVER, and delete everything below the last such line. (Leave the SERVER lines exactly as they are.) Then replace everything you just deleted with the single line:
USE_SERVER
Make sure that the lines are all distinct, i.e. each SERVER line is on a separate line and the USE_SERVER line is also a separate line, and there are no extra characters at the end. This may require some editing depending upon your operating system. (Windows, Mac, and UNIX have different conventions for marking the end of a line, but only one version of the license file is provided, usually for Windows.)
Making these changes should preclude the need to update the license file on your local installation every time ITS changes the master file due to a new version or to the yearly renewal. You will need the full license file again if you upgrade the software, however.
2. Use a text editor to modify the .cshrc (C shell or tcsh) or .profile (Korn shell or bash) to contain the following lines so that the IDL setup will be done automatically upon login. Then log out and re-login.
- For C-shell:source /uva/bin/idl_setup
- For K-shell (note period at beginnning): . /uva/bin/idl_setup.ksh
3. Running IDL (/uva/bin) should be part of your PATH variable by default).
Start IDL Development Environment:
idlde
Start IDL w/o motif graphical user interface:
idl
4. Running IDL remotely
If you are running IDL on a UNIX machine other than the one you originally logged onto (i.e. running it remotely), the DISPLAY environment variable must be set. You can check its value by typing
printenv $DISPLAY
If you have logged in via ssh or slogin you should see a response similar to
DISPLAY=machine.remote.virginia.edu:10.0
If you do not see this, you should make sure that you have logged in with X11 forwarding enabled. This may require adding an option -X to your ssh line.
Access From Windows
Users who wish to install IDL on their PC running Windows can download IDL from the ITS software licensing database. It is necessary to obtain a license file from the licensing database regardless of whether the software was downloaded or obtained from Research Computing.
Note that to use one of the floating network licenses, the PC must be connected to the University network either on Grounds or through an ISP. Off-Grounds use must take place via the UVa Anywhere VPN client.
For installation instructions, please refer to the appropriate section of the Installation Guide. Refer to the section entitled "Configure Clients to Access the License Server" for instructions on licensing IDL. You must download the license.dat file from the licensing database.
You should have the full license file downloaded to your computer before you begin the installation. We recommend that when you complete the installation, you should copy the license.dat file to some name such as license.full, then edit the license.dat file. Find the lines beginning SERVER, and delete everything below the last such line. (Leave the SERVER lines exactly as they are.) Then replace everything you just deleted with the single line:
USE_SERVER
Make sure that the lines are all distinct, i.e. each SERVER line is on a separate line and the USE_SERVER line is also a separate line, and there are no extra characters at the end. This may require some editing depending upon your operating system. (Windows, Mac, and UNIX have different conventions for marking the end of a line, but only one version of the license file is provided, usually for Windows.)
This should preclude the need to update the license file on your local installation every time ITS changes the master file due to a new version or to the yearly renewal. You will need the full license file again if you upgrade the software, however.
Access From Macs
IDL can be downloaded from the vendor's download page (registration required). Alternatively, users can come to the Scholar's Lab to borrow a copy on CDROM. It is necessary to obtain a license file from the licensing database regardless of whether the software was downloaded or obtained from Research Computing.
Note that to use one of the floating network licenses, the Macintosh must be connected to the University network either on grounds or through an ISP. Off-Grounds use must take place via the UVa Anywhere VPN client.
To install on OS X, you must have Apple's X11 software on your system. Note that X11 is not installed by default; a custom installation is required. X11 can also be installed separately by downloading it from Apple's website (10.3 and earlier) or by obtaining it from the installation DVD (10.4 and later).
For more detailed installation instructions, please refer to the appropriate section of the Installation Guide. Refer to the section on licensing IDL for UNIX and Macintosh" for instructions on how to license IDL. The required license.dat file can be downloaded from the licensing database.
You should have the full license file downloaded to your computer before you begin the installation. We recommend that when you complete the installation, you copy the license.dat file to some name such as license.full, then edit the license.dat file. Find the lines beginning SERVER, and delete everything below the last such line. (Leave the SERVER lines exactly as they are.) Then replace everything you just deleted with the single line:
USE_SERVER
Make sure that the lines are all distinct, i.e. each SERVER line is on a separate line and the USE_SERVER line is also a separate line, and there are no extra characters at the end. This may require some editing depending upon your operating system. (Windows, Mac, and UNIX have different conventions for marking the end of a line, but only one version of the license file is provided, usually for Windows.)
This should preclude the need to update the license file on your local installation every time ITS changes the master file due to a new version or to the yearly renewal. You will need the full license file again if you upgrade the software, however.
Getting Help with IDL
The IDL Online Help can be accessed from the Help menu in the IDL Development Environment or by typing a ? at the IDL prompt, e.g. IDL> ?. It provides documentation of IDL procedures, functions, and keywords, and information on the status of the IDL environment. The Online help can also be invoked outside the IDL environment.
On Windows, select Start -> Programs -> Research Systems IDL 7.0 -> IDL Help.
From UNIX and Mac OS X, execute the following at the UNIX prompt:
idlhelp
The manuals for IDL can also be accessed online in the UNIX environment.
On UNIX and Mac OS X, execute the following at the UNIX prompt:
idlman
The ITTVIS website provides quite a few tutorials in IDL. Beginners should start with Introduction to Programming in IDL tutorials which describes the basics of IDL as well as contains tutorials that teach IDL concepts and techniques.
Advanced tutorials in signal processing, image processing and advanced graphics are also available at the ITT Vis tutorial site.
ITS's license for IDL allows for only one person at the University (a member of ITS Research Computing Support) to contact Research Systems Inc., the maker of IDL, concerning technical problems.
IDL Examples
The IDL Demo Applications are a series of programs written in the IDL language that demonstrate some of the ways IDL can help to visualize data. They can be accessed from within the IDL environment by typing demo at the IDL prompt, i.e. IDL> demo. The IDL Demo Applications can also be invoked outside the IDL environment.
On Windows, select Start -> Programs -> Research Systems IDL 7.0 -> IDL Demo.
On UNIX, execute the following at the UNIX prompt:
idldemo
