gotwols@warper.jhuapl.edu (Bruce Gotwols) (07/15/90)
Several people have posted questions asking about the difference between IDL and PV-WAVE. IDL (Interactive Data Language) is a product of RSI (I forget the meaning, Research ...) and is the creation of David Stern. IDL goes back to PDP-11 days, but I don't know the exact chronology. I have used it since about 1984 on a VAX. PV-Wave is a product that builds on top of IDL, providing menus and other useful utilities. There is something very strange about the fact that most users of PV-Wave are unaware that they are using a product which might be classified as a shell that sits on top of IDL. Don't attack me... it does more than just provide menus, but basically it is NOT a language since, it relies on IDL to provide a language you can program in. So the user who recently said that PV Wave is far superior to IDL must have liked the menus, but as far as programming is concerned he is wrong since the two are identical as a programming language. For my own part, I attended a demo of the PVWAVE product and decided not to purchase it. I almost never find a product that does the sort of specialized things I do, so the nice PVWAVE menus were not worth purchasing since I wouldn't use them anyway. For more routine stuff you might easily come to the opposite conclusion. I must admit that I was not pleased that neither the PVWAVE salesman nor the PVWAVE manuals (at least at that time) admitted that their product was built on top of the IDL language. I guess that's one nice benefit that will come out of this new combined newsgroup, a bit of information exchange between users of both products. So it is possible for IDL and PV-Wave users to exchange programs as long as the programs don't rely on specific features that are only present in the add-on PV-Wave product. A shared library of Astronomy oriented IDL source code allready exists at the Goddard Space Flight center, but I believe it has restricted access. I have contacted the people in charge and hope they will soon make some or all of their holdings available for people on the Internet. About 500 routines are also available from the Johns Hopkins Applied Physics Laboratory, most written by Ray Sterner, and an infinitesmal number by myself. We hope to contribute the more general ones to an IDL remote ftp site when one is finally set up. Most of these routines were initially written in IDL version 1, which runs only on a VAX. Currently Ray is converting many of them to IDL version 2, which is compatible with both VAX under VMS, and SUN under UNIX. -- -- Bruce L. Gotwols Johns Hopkins University, Applied Physics Lab., Laurel MD 20723 Internet: gotwols@warper.jhuapl.edu (128.244.176.48)
lumsdon@dtoa1.dt.navy.mil (Lumsdon) (07/16/90)
Following Bruce's excellent posting, I'd like to point out a couple of things. The pricing for IDL and PV-WAVE was similar, when I looked about 8 months ago. Both companies are in the Denver/Boulder CO area. Precision Visuals licensed the technology, source, and manuals from RSI. I believe that the newer versions of IDL and PV-WAVE work with X-windows, and use names rather than numbers for parameters to some commands. IDL supports more output devices, Grinnell image processor and Gould image processor, for example. The source for creating menus (using the PV-WAVE facility) is included. It might be possible to write equivalent commands for IDL without a lot of trouble. For version of PV-WAVE that we have, one of the three manuals is identical to one of the IDL manuals. The user library is identical to that supplied with IDL. So, the two products are quite similar in ancestry, capability, and price. -------------------------- Esther Lumsdon -------------------------------- lumsdon@dtoa1.dt.navy.mil lumsdon@dtrc.dt.navy.mil lumsdon%dtrc.navy.mil@uunet.uu.net "Wherever you go, there you are" -Buckaroo Bonzai
steve@bat.lle.rochester.edu (Steve Swales) (07/17/90)
In article <5944@aplcen.apl.jhu.edu> gotwols@warper.jhuapl.edu (Bruce Gotwols) writes: >There is something very strange about the fact that most users of PV-Wave >are unaware that they are using a product which >might be classified as a shell that sits on top of IDL. and: >I must admit that I was not >pleased that neither the PVWAVE salesman nor the PVWAVE manuals (at least at >that time) admitted that their product was built on top of the IDL language. I have heard (from an informed source) that in fact it was stipulated by RSI in their license to PV that the relationship NOT be revealed. This is indeed strange, IMHO, like C++ trying to deny relationship to C (or vice versa). The idea, as I was told, is that RSI does not want to be bothered by PV-WAVE customers since they already have there own base of IDL people. While I can understand this desire, I don't think that this stipulation was the way to go, and in fact, the whole thing seems kind of paranoid, if true. Anyone know the true facts? >I guess that's one nice benefit that will come out of this new combined >newsgroup, a bit of information exchange between users of both products. Yup. In fact, the whole point of putting pvwave in the name was to let the PV-WAVE people know that the IDL people were out there (and vice versa), and worth talking to. -steve -- -------------------------------------------------------+"Come, Watson, come!" Steve Swales (716) 275-0265,-3857,-5101| he cried. "The game is steve@bat.lle.rochester.edu (128.151.32.111)| afoot. Not a word! {decvax,harvard,ames,rutgers}!rochester!ur-laser!steve| Into your clothes and University of Rochester 250 East River Road| come!" S.H. Laboratory for Laser Energetics Rochester, NY 14623| 'The Abbey Grange'