comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Re: On the differences between idl and pvwave

Re: On the differences between idl and pvwave
type: item
description: In article <51116@netnews.upenn.edu> yee@mipgsun.mipg.upenn.edu (Conway Yee) writes:(only slightly trimmed) > > From what I understand, the company that markets pvwave licensed > idl and markets it under their own name. In the near future, my > lab will be purchasing idl/pvwave. From what I can see, the two > are identical products. What are the essential differences between > the two and which should we buy? At the National Severe Storms Lab we have IDL. My local university, which shall go unnamed, bought PVWAVE. They are indeed 99% the same product. The essential differences: Graphics commands especially go by the 'keyword' concept in PVWAVE, while IDL goes (VAX version) by 'parameters': IDL> CONTOUR,agrid,[1,2,5,10,20,50,100] WAVE>CONTOUR,agrid,labels=[1,2,5,10,20,50,100] The latter is too much typing for an INTERACTIVE programming language IMO. I also believe that the former is better for 'sophisticated' programming where you might build commands then execute them (if you are so inclined). Also, both come with a 'user library', sort of a small scale IMSL-like set of routines. IDL's is useful. PVWAVE's was full of bugs. PVWAVE comes with a 'window based tutorial' which I found simply a nuisance. The way to learn IDL, like any programming language, is by cloning some short and sweet programs that do typical things (I have such a set of screen size programs that do elementary plotting, contouring, map drawing, map plotting, basic image things, etc...call me). I could ramble a long time on this. IDL is a good scientific programming language. I used to use FORTRAN, now I use IDL. I am willing to provide information, ranging from getting a sample manual to you, to sending real programs that do real science. Dave Keller "I own no stock in Research Systems Incorporated"
creator: keller
date: 1991-09-20T03:12:51-00:00

Re: On the differences between idl and pvwave
type: item
description: |>At the National Severe Storms Lab we have IDL. My local university, which |>shall go unnamed, bought PVWAVE. |>They are indeed 99% the same product. |>The essential differences: |>Graphics commands especially go by the 'keyword' concept in PVWAVE, while |>IDL goes (VAX version) by 'parameters': |> IDL> CONTOUR,agrid,[1,2,5,10,20,50,100] |> WAVE>CONTOUR,agrid,labels=[1,2,5,10,20,50,100] |>The latter is too much typing for an INTERACTIVE programming language IMO. |>I also believe that the former is better for 'sophisticated' programming |>where you might build commands then execute them (if you are so inclined). |> |>Also, both come with a 'user library', sort of a small scale IMSL-like |>set of routines. IDL's is useful. PVWAVE's was full of bugs. |> |>PVWAVE comes with a 'window based tutorial' which I found simply a nuisance. |>The way to learn IDL, like any programming language, is by cloning some |>short and sweet programs that do typical things (I have such a set of |>screen size programs that do elementary plotting, contouring, map drawing, |>map plotting, basic image things, etc...call me). |> |>I could ramble a long time on this. IDL is a good scientific programming |>language. I used to use FORTRAN, now I use IDL. I am willing to provide |>information, ranging from getting a sample manual to you, to sending real |>programs that do real science. |> |>Dave Keller "I own no stock in Research Systems Incorporated" |> |> We, this certainly deserves a response (being we are the local University that bought PVWAVE). 1). For people who know PVWAVE, one does not have to use keywords but can achieve the same 'parameter' effect of IDL by programming the procedure appropriately...so this point is invalid. The keyword concept is both useful and good. It provides a way of checking if a parameter is present and providing a default if it is not present. Furthermore, if all one does is interactive programming, then the user/"programmer" loses much of the power and flexibil…
creator: dwight
date: 1991-09-20T15:54:25-00:00

Re: On the differences between idl and pvwave
type: item
description: Just this morning I noticed another difference between IDL and WAVE -- WAVE is supposed to support CGM output whereas IDL does not claim to. Unfortunately, it turns out that the WAVE CGM does not conform to the standard. This is a problem for me, as the software that drives our film recorder supports CGM, but chokes on the files from WAVE. The film recorder does not support any of the other formats written by IDL or WAVE. I was hoping RSI would have solved the non-standard CGM problem, but CGM is not listed in the supported "devices." Has anyone come up against this problem, or have any suggestions for me? Thanks, Jennifer Dungan jennifer@vessna.arc.nasa.gov TGS Technology Inc. MS 242-4 NASA/GSFC Moffett Field, CA 94035 (415) 604-3618
creator: jennifer
date: 1991-09-20T19:25:02-00:00

Re: On the differences between idl and pvwave
type: item
description: IDL has keyword parameters too, in version 2.0. I believe it is backward compatible and can still understand the non-keyword versions of commands too. It has been my experience that IDL customer support is very responsive. It would be interesting to know how the whole thing with IDL/PV-WAVE happened-- seems kind of strange! Linda Hunt
creator: hunt
date: 1991-09-20T19:50:36-00:00

Re: On the differences between idl and pvwave
type: item
description: In article <1991Sep20.192502.9749@news.arc.nasa.gov> jennifer@gaia.arc.nasa.gov (Jennifer Dungan) writes: > Just this morning I noticed another difference between IDL and WAVE > -- WAVE is supposed to support CGM output whereas IDL does not claim > to. Unfortunately, it turns out that the WAVE CGM does not conform (other lines delete) Actually, IDL produces NCAR Graphics Metacode files which are CGM files. I'll bet the WAVE code is the same, but they may have "improved" it. My limited experience with the NCAR CGM files are that they were fine except their text size has a bug (or is non-standard CGM) -- text which looks fine from NCAR routines is tiny from CGM translators.
creator: bdavis
date: 1991-09-23T17:42:24-00:00

Re: On the differences between idl and pvwave
type: item
description: In article <1991Sep20.031251.29717@uokmax.ecn.uoknor.edu>, keller@nsslsun.nssl.uoknor.edu (Dave Keller) writes... > Graphics commands especially go by the 'keyword' concept in PVWAVE, while > IDL goes (VAX version) by 'parameters': > IDL> CONTOUR,agrid,[1,2,5,10,20,50,100] > WAVE>CONTOUR,agrid,labels=[1,2,5,10,20,50,100] > The latter is too much typing for an INTERACTIVE programming language IMO. > I also believe that the former is better for 'sophisticated' programming > where you might build commands then execute them (if you are so inclined). You're using an *OLD* version of IDL. This is comparing apples and oranges. Keywords originated in IDL (version 2) before IDL and PVWAVE split apart. Keywords are an immensely useful concept. The sophistication of my IDL software has increased exponentially since keywords were introduced. It is a hell of a lot easier for *OPTIONAL* information to propagate through a chain of subroutines if the keyword concept is used. Bill Thompson
creator: thompson
date: 1991-09-24T20:23:49-00:00