rfinch@caldwr.water.ca.gov (Ralph Finch) (07/28/90)
I did find something which for us is worth the price difference, namely, the capability of calling IDL/Wave from Fortran. For others your mileage may vary. -- Ralph Finch 916-445-0088 rfinch@water.ca.gov ...ucbvax!ucdavis!caldwr!rfinch Any opinions expressed are my own; they do not represent the DWR
gotwols@warper.jhuapl.edu (Bruce Gotwols) (07/28/90)
In a recent posting, Ralph Finch writes that he has found a reason to pay the extra $1200. for PV WAVE rather than buying IDL from RSI: > I did find something which for us is worth the price difference, > namely, the capability of calling IDL/Wave from Fortran. For others > your mileage may vary. Sorry, but I disagree with his conclusion. In IDL version 1 you can call Fortran or C or any other language supported on the VAX two different ways: 1. by the so called mailbox, and 2, by the LINKIMAGE mechanism. The LINKIMAGE mechanism is fast but a bit cumbersome to set up for a beginner. Nevertheless it is used here a lot (don't ask me for the details.). the Mailbox scheme works too but is slower and should be considered to be obselete. In version 2 of (VAX only) IDL a new scheme was made available which is practically trivial once you see an example. It has the name CALL_VMS and allows routines written in other languages to be called without having to do a lot of system mumbo jumbo. Linkimage is also available in Version 2, but the obsolete mailbox scheme mentioned above has been eleminated. I routinely call routines written in both C and Fortran in both versions 1 and 2 of VAX IDL. Someone even wrote a series of routines that call the National Instruments GPIB (IEEE-488) routines so we could do real time data acquistion from within the IDL environment! So apparently BOTH IDL and PV-WAVE provide hooks to allow C or Fortran routines to be called. Unfortunately this is currently not the case for SUN IDL. -- -- Bruce L. Gotwols Johns Hopkins University, Applied Physics Lab., Laurel MD 20723 Internet: gotwols@warper.jhuapl.edu (128.244.176.48)
gotwols@warper.jhuapl.edu (Bruce Gotwols) (07/28/90)
In a posting of mine set forth on an unsuspecting world about five minutes ago I stated that I disagreed with Ralph Finch's conclusion that he had found something that PV-WAVE can do that IDL cannot. Unfortunately for me, I did not read Ralph's statement carefully enough. He mentioned calling IDL FROM within FORTRAN programs, not the other way around as I had first thought. I know nothing about the topic of calling IDL from Fortran, so I withdraw my disagreement with Ralph. If I had any knowledge of how to withdraw my former posting I would do so. Sorry for the smoke screen I created. -- -- Bruce L. Gotwols Johns Hopkins University, Applied Physics Lab., Laurel MD 20723 Internet: gotwols@warper.jhuapl.edu (128.244.176.48)