IDL 6.0 full review
Scientific instruments are good at collecting data, but some people need to see images, instead of numeric tables, in order to interpret data easily.
Research Systems’ IDL 6.0 is the best of its kind at providing visual images that represent statistics – it can turn radar into weather maps, MRI signals into pictures of a skull, and space X-ray signals into maps of the universe (see “Getting the big picture”).
Other programs, such as The MathWorks’ Matlab 6.5 (mmmm3; December 2002) and Wolfram Research’s Mathematica 5 (mmmm2; January 2004), can map 2D and 3D data arrays into dazzling colour plots. But IDL’s tool set gives you more types
of charts, as well as better chart-labelling components that make it easier to generate finished presentations.
Version 6.0’s new iTools feature makes complex plotting easier for beginners, while the free IDL Virtual Machine lets non-users customize display features.
IDL stands for Interactive Data Language, a name that doesn’t really explain much. The application uses a C-like programming language that offers hundreds of special functions for different kinds of data display; you might call IDL “Adobe Photoshop for scientists.” For example, if you have seismic data to chart, you can elect to display it in as many as 20 global projections, using the program’s variety of built-in colour tables.
Version 6.0 of IDL introduces “intelligent tools” called iTools (not to be confused with Apple’s former name for .Mac). This object-oriented programming system has an assortment of pre-made tools that help you produce graphic representations of 2D and 3D plots (line, scatter, polar, and histogram), surface representations, contour maps, image displays, and volume visualizations. iTools give you many types of displays with a single command.
iTools commands also can be modified and combined into custom libraries.
With version 6.0, Research Systems is introducing IDL Virtual Machine, a freely distributable module that runs compiled IDL code. IDL VM is not yet bug free. Users who upgraded from version 5.5 have encountered problems with iTools code in the virtual machine. Those problems, and glitches in IDL object graphics, were mostly caused by the previous version’s non-Unix file conventions. Very few problems, though, have been reported with the virtual machine running from the native 6.0 code.
The Mac version of IDL is actually Unix. To run it, you need OS X 10.3, because Panther’s version of X11 Windows eliminates some of the problems with version 5.5. This also applies to the virtual machine, so you can’t distribute IDL code to your Mac pals unless they’ve upgraded to Panther, too.