| Linux Question [message #42567] |
Wed, 16 February 2005 09:54  |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Ok, you Linux guys,
I have to break down and install Linux so I can sort out some
X Windows problems with my IDL widgets. Which flavor is the easiest
to install for the, uh, less technically astute members of
our esteemed organization? :-)
Cheers,
David
P.S. I'll probably put it on an old DELL laptop I have
around here and have been using as a doorstop.
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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| Re: Linux Question [message #42617 is a reply to message #42567] |
Thu, 17 February 2005 08:33  |
R.G.Stockwell
Messages: 163
Registered: October 2004
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Senior Member |
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"Paul Van Delst" <paul.vandelst@noaa.gov> wrote in message
news:cv0kuo$2cj$1@news.nems.noaa.gov...
> David Fanning wrote:
...
>> It's not really a matter of intelligence. Most of the
>> people in an IDL class have advanced degrees in physical
>> sciences. It is something else, and I can't really put my
>> finger on it. (I used to think it was because they were forced
>> to use LINUX computers, but now I know better.) They
>> don't understand programming at all. They don't really
>> know what a variable is, they don't know how to type
>> a program, they don't understand how windows work on
>> their computers. Really basic stuff I would have thought
>> you learned as a physical science undergraduate. But
>> if so, they have forgotten a lot of it.
>
> Ah, I know what you mean. When I first came ot the US ('93) I was amazed
> at the number of graduate students (in science fields) that didn't know
> how computers worked and had never programmed at all. How can that be?!?
> Bizarre. Didn't everybody learn about registers, CPUs, ALUs, Math
> Coprocessors, etc. in their Experimental Methods classes?
I can't tell you how happy this makes me.
I read this and I think "job security", after all, someone has to
know how to compute.
Ahh!
Thanks for the morning "pick me up".
:)
-bob "whistling while he works"
PS and know that I know how to find DLMS, I feel that I may
have achieved complete and utter mastery over all computer related fields.
:)
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| Re: Linux Question [message #42627 is a reply to message #42567] |
Thu, 17 February 2005 02:23 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Paolo Grigis writes:
> Slowly finding you're way through the 10000+ pages of documentation,
> you discover on page 3856 of the appendices the section that you should
> have read first: "The X Windows Device". You read the chapter carefully
> twice, and you summ up your findings: out there exist direct color, true
> color, pseudo color, static color, gray scale, static gray. The last 2
> don't interest you, since you have already managed B&W, sort of.
> So which one should you pick? You learn they come in different flavours,
> 8 bit, 16 bit, 24 bit. Also there is a mention of colormaps: they come
> as shared, private, static (but you find no mention of dynamics ones,
> pity, as an astrophysicists you have been trained to think that
> hydrodynamics is superior to hydrostatics). So, now, which one will
> work for you? Of course the guide does not help you in *that* matter,
> so you choose to apply the "scientific method": try out all the
> possible combination until you find the one that suits you
> (but still you're not really sure why that particular
> combination works and the others failed...).
Here's the problem in a nutshell. But talk about
embellishing an anecdote!
Cheers,
David
P.S. Let's just say an article like this in the morning
gets the day started right! :-)
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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| Re: Linux Question [message #42628 is a reply to message #42567] |
Thu, 17 February 2005 01:56 |
Paolo Grigis
Messages: 171
Registered: December 2003
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Senior Member |
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Paolo Grigis wrote:
>
> Marshall Perrin wrote:
>
>> David Fanning <davidf@dfanning.com> wrote:
>>
>>> I am always amazed with what people put up with,
>>> but this was really an eye-opening experience.
>>> I recommend *anyone* who writes software for a living go spend a
>>> couple of months with the end-users.
>>> You will never be the same. :-)
>>
>>
>>
>> I feel that someone needs to stand up here and offer a valiant defense
>> of the astrophysics community, but I fear it's too late and we've
>> all already been irrevocably branded as hopeless luddites. :-)
>
>
> Thanks Marshall!
>
>>
>> I think part of the problem is that IDL ships with poor default settings
>> in many cases. It can be configured to do the right thing, if you know
>> how to tweak your .idlstartup file to add some DECOMPOSED and RETAIN
>> keywords, etc, but you shouldn't have to do that to get reasonable
>> functionality! I think many astronomers come to IDL with previous
>> experience
>> with things like Matlab or Mathematica, where you *don't* need to do
>> that sort of tweaking. Window repaints work correctly in Mathematica
>> right away! So when faced with IDL windows that get permanently
>> damaged as soon as something passes in front of them, why isn't it
>> reasonable to assume that's "just how IDL is"?
>
>
> Just to *reiterate* it: let's say you've just started you're PhD thesis,
> you sit in front of you're shiny new linux box, and just spend a couple
> of days and nights learning IDL. You don't feel like a newbye anymore,
> and you think you're ready for your first big project:
> a nice colored movie of your favorite supernova exploding.
> You have made a nice plan in your head on how the animation will
> look like and you think you might be optioned for the next academy
> award.
>
> Proud, you start coding and displaying your frames... just to find out
> your animation looks like it was done in the thirties: desperately black
> and white. You think: IDL cannot be so backwards, can't it? Suddenly you
> also find out that when you put your mouse cursor over the plot windows,
> colors magically show up, making your plot so nice and screwing
> everything else up, but who cares if you're nice background image of M81
> by Hubble now looks like an old X-ray false color image...
> So you gear your hope up, but still find the limitation of having to
> keep your mouse on the windows a little harsh. Brilliant idea: check
> up the documentation. You type "? colour" at the command line and
> a fine message windows tells you: the topic "COLOUR" does not exist.
> Fine, you remember RSI HQ being based in colorado and not in colourado,
> so you try again "? colour", but that doesn't work either. So what?
Of course, the second time that was meant to read: "? color"
>
> Slowly finding you're way through the 10000+ pages of documentation,
> you discover on page 3856 of the appendices the section that you should
> have read first: "The X Windows Device". You read the chapter carefully
> twice, and you summ up your findings: out there exist direct color, true
> color, pseudo color, static color, gray scale, static gray. The last 2
> don't interest you, since you have already managed B&W, sort of.
> So which one should you pick? You learn they come in different flavours,
> 8 bit, 16 bit, 24 bit. Also there is a mention of colormaps: they come
> as shared, private, static (but you find no mention of dynamics ones,
> pity, as an astrophysicists you have been trained to think that
> hydrodynamics is superior to hydrostatics). So, now, which one will
> work for you? Of course the guide does not help you in *that* matter,
> so you choose to apply the "scientific method": try out all the
> possible combination until you find the one that suits you
> (but still you're not really sure why that particular
> combination works and the others failed...).
>
> I am sure that the above picture is not too far from the actual
> experience of at least some people, and maybe even a few
> "computer-wise" ones.
>
> Ciao,
> Paolo
>
>>
>> That's not to say I disagree completely with the tone of this thread.
>> There *are* a lot of people who don't understand computing nearly as
>> well as perhaps they should; I'd love to see more computer emphasis
>> added to the undergraduate physics curriculum, but the invariable
>> faculty response is "but there's already too much material; what
>> courses should we drop if we add a computer requirement or two?"
>> Still, I think it needs to happen sooner or later. But I see a
>> distinction between fundamental issues of numerical data analysis
>> (e.g. representation of floating-point numbers, error propagation,
>> algorithms, and so on) versus details specific to some individual
>> piece of software (setting RETAIN=2 or knowing how to convert between
>> DATA and NORMALIZED coordinates, or whatever). One should strive to
>> minimize how much of the latter one needs to know, so that you can
>> concentrate on the former! In my opinion, something like imdisp or
>> tvimage should become *standard* with IDL: too many people out there
>> end up learning "tv" first and then getting stuck rolling their own
>> more useful display codes from scratch, and that's a waste...
>>
>> On a regular basis, I program in IDL, C/C++, Perl, Tcl/Tk, various
>> shells, and Motorola DSP assembler (and occasionally I end up in
>> Python or Fortran too). That menagerie of languages is my problem, not
>> yours, but I hope you don't fault me for wanting to get the most
>> science done in IDL as possible with the minimum amount of screwing
>> around with configuration parameters or learning language esoterica!
>> (Same reason why I, and nearly every other astronomer I know, have
>> switched to Macs as much as possible: minimal need to screw around for
>> hours just to get things working!)
>>
>> I'll go crawl back in my hole with the other end-users for a while
>> now and be quiet again. :-)
>>
>>
>> - Marshall
>>
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| Re: Linux Question [message #42629 is a reply to message #42567] |
Thu, 17 February 2005 01:53 |
Paolo Grigis
Messages: 171
Registered: December 2003
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Senior Member |
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Marshall Perrin wrote:
> David Fanning <davidf@dfanning.com> wrote:
>
>> I am always amazed with what people put up with,
>> but this was really an eye-opening experience.
>> I recommend *anyone* who writes software for a
>> living go spend a couple of months with the end-users.
>> You will never be the same. :-)
>
>
> I feel that someone needs to stand up here and offer a valiant defense
> of the astrophysics community, but I fear it's too late and we've
> all already been irrevocably branded as hopeless luddites. :-)
Thanks Marshall!
>
> I think part of the problem is that IDL ships with poor default settings
> in many cases. It can be configured to do the right thing, if you know
> how to tweak your .idlstartup file to add some DECOMPOSED and RETAIN
> keywords, etc, but you shouldn't have to do that to get reasonable
> functionality! I think many astronomers come to IDL with previous experience
> with things like Matlab or Mathematica, where you *don't* need to do
> that sort of tweaking. Window repaints work correctly in Mathematica
> right away! So when faced with IDL windows that get permanently damaged
> as soon as something passes in front of them, why isn't it reasonable to
> assume that's "just how IDL is"?
Just to *reiterate* it: let's say you've just started you're PhD thesis,
you sit in front of you're shiny new linux box, and just spend a couple
of days and nights learning IDL. You don't feel like a newbye anymore,
and you think you're ready for your first big project:
a nice colored movie of your favorite supernova exploding.
You have made a nice plan in your head on how the animation will
look like and you think you might be optioned for the next academy
award.
Proud, you start coding and displaying your frames... just to find out
your animation looks like it was done in the thirties: desperately black
and white. You think: IDL cannot be so backwards, can't it? Suddenly you
also find out that when you put your mouse cursor over the plot windows,
colors magically show up, making your plot so nice and screwing
everything else up, but who cares if you're nice background image of M81
by Hubble now looks like an old X-ray false color image...
So you gear your hope up, but still find the limitation of having to
keep your mouse on the windows a little harsh. Brilliant idea: check
up the documentation. You type "? colour" at the command line and
a fine message windows tells you: the topic "COLOUR" does not exist.
Fine, you remember RSI HQ being based in colorado and not in colourado,
so you try again "? colour", but that doesn't work either. So what?
Slowly finding you're way through the 10000+ pages of documentation,
you discover on page 3856 of the appendices the section that you should
have read first: "The X Windows Device". You read the chapter carefully
twice, and you summ up your findings: out there exist direct color, true
color, pseudo color, static color, gray scale, static gray. The last 2
don't interest you, since you have already managed B&W, sort of.
So which one should you pick? You learn they come in different flavours,
8 bit, 16 bit, 24 bit. Also there is a mention of colormaps: they come
as shared, private, static (but you find no mention of dynamics ones,
pity, as an astrophysicists you have been trained to think that
hydrodynamics is superior to hydrostatics). So, now, which one will
work for you? Of course the guide does not help you in *that* matter,
so you choose to apply the "scientific method": try out all the
possible combination until you find the one that suits you
(but still you're not really sure why that particular
combination works and the others failed...).
I am sure that the above picture is not too far from the actual
experience of at least some people, and maybe even a few
"computer-wise" ones.
Ciao,
Paolo
>
> That's not to say I disagree completely with the tone of this thread.
> There *are* a lot of people who don't understand computing nearly as
> well as perhaps they should; I'd love to see more computer emphasis
> added to the undergraduate physics curriculum, but the invariable
> faculty response is "but there's already too much material; what
> courses should we drop if we add a computer requirement or two?"
> Still, I think it needs to happen sooner or later. But I see a
> distinction between fundamental issues of numerical data analysis
> (e.g. representation of floating-point numbers, error propagation,
> algorithms, and so on) versus details specific to some individual
> piece of software (setting RETAIN=2 or knowing how to convert between
> DATA and NORMALIZED coordinates, or whatever). One should strive to
> minimize how much of the latter one needs to know, so that you can
> concentrate on the former! In my opinion, something like imdisp or
> tvimage should become *standard* with IDL: too many people out there
> end up learning "tv" first and then getting stuck rolling their own
> more useful display codes from scratch, and that's a waste...
>
> On a regular basis, I program in IDL, C/C++, Perl, Tcl/Tk, various
> shells, and Motorola DSP assembler (and occasionally I end up in
> Python or Fortran too). That menagerie of languages is my problem, not
> yours, but I hope you don't fault me for wanting to get the most
> science done in IDL as possible with the minimum amount of screwing
> around with configuration parameters or learning language esoterica!
> (Same reason why I, and nearly every other astronomer I know, have
> switched to Macs as much as possible: minimal need to screw around for
> hours just to get things working!)
>
> I'll go crawl back in my hole with the other end-users for a while
> now and be quiet again. :-)
>
>
> - Marshall
>
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| Re: Linux Question [message #42632 is a reply to message #42567] |
Wed, 16 February 2005 23:55 |
Karsten Rodenacker
Messages: 98
Registered: July 1997
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Member |
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Hay, nice thread this night!
Interesting to see how moving such a simple question is!
David, this thread could become a new Tutorial.
To add a bit from me: after years of workstation usage (VMS/Unix/HP),
years of PC (mostly Windows, linux (Suse)) I now decided to go over to Mac
OS X, enchanted by the seemingly simplicity and the obvious lack of
distorted thinking and reasoning mostly caused by usage of Windows.
Even if that might be unrealistic: I think switching on the virgin Mac,
installing IDL, running the routines necessary is far better than spending
years with troubles and losses caused by Windows/linux problems. And than,
after some days/weeks/months of satisfying work I will even decide to use
X windows with the (X)emacs (?) running with idlwave ...
Please don't spoil my phantasy! I hope really to overcome this
unbelievable corruption of thinking caused by the usage of MS software!
Regards
Karsten
On Wed, 16 Feb 2005 10:54:48 -0700, David Fanning <davidf@dfanning.com>
wrote:
> Ok, you Linux guys,
>
> I have to break down and install Linux so I can sort out some
> X Windows problems with my IDL widgets. Which flavor is the easiest
> to install for the, uh, less technically astute members of
> our esteemed organization? :-)
>
> Cheers,
>
> David
>
> P.S. I'll probably put it on an old DELL laptop I have
> around here and have been using as a doorstop.
>
--
Karsten Rodenacker
------------------------------------------------------------ -------- :-)
GSF - Forschungszentrum Institute of Biomathematics and Biometry
D-85758 Oberschleissheim Postfach 11 29
Karsten.Rodenacker@gsf.de | http://ibb.gsf.de/
http://ibb.gsf.de/homepage/karsten.rodenacker/
Tel: +49 89 31873401 | FAX: ..3369
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| Re: Linux Question [message #42634 is a reply to message #42567] |
Wed, 16 February 2005 20:44 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Michael Wallace writes:
> To whom within RSI do we send our ground swell of letters? Do you think
> RSI would listen, if we as the IDL newsgroup, came up with a list of the
> top things we'd most like to see implemented? Instead of each one of us
> requesting all sorts of different little things, find the things that we
> have in common and all of us get behind that effort to get it in? Grass
> roots, baby!! ;-)
I think we tried that once, to indifferent success. :-)
But, yes, they listen. Why do you think we still have
a Mac version of IDL?
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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| Re: Linux Question [message #42635 is a reply to message #42567] |
Wed, 16 February 2005 20:34 |
Michael Wallace
Messages: 409
Registered: December 2003
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Senior Member |
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> No, no. I agree with you *completely*. It is nonsense
> in this day and age for IDL to work so poorly out of
> the box. And it is ruinous for people who want to promote
> and sell IDL. Part of my frustration with iTools is that
> I see such a lot of effort on stuff that's not needed,
> and so little attention paid to the simple things that
> could make a world of difference to the people who are
> actually trying to use IDL.
Regarding iTools, the first time iTools was included, I wanted to try
things out. I bring up an iTool and click and BOOM! There went my IDL
session and I think it even tool my shell along with it. There also
went any interest I had in iTools. After a little research, I figured
out the problem, but iTools are nothing more than a whiz-bang feature
that has no practical application (for me).
> But why are you responding to me! There should be
> a ground swell of letters directed to RSI. Why are
> so many people willing to settle for this?
To whom within RSI do we send our ground swell of letters? Do you think
RSI would listen, if we as the IDL newsgroup, came up with a list of the
top things we'd most like to see implemented? Instead of each one of us
requesting all sorts of different little things, find the things that we
have in common and all of us get behind that effort to get it in? Grass
roots, baby!! ;-)
-Mike
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| Re: Linux Question [message #42643 is a reply to message #42567] |
Wed, 16 February 2005 16:30 |
Mark Hadfield
Messages: 783
Registered: May 1995
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Senior Member |
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David Fanning wrote:
> ... It's only later that
> night, after the third or forth margarita that
> I get very, very depressed.
There was a marvellous anti-alcohol (well anti-alcohol-abuse) ad in NZ a
few years ago. A guy is holding forth at a pub (US translation bar) to a
friend about his problems: unsuccessful at work, wife hates him,
disqualified from driving. He goes on about this while knocking back
several glasses of beer. "If it was just one problem I could deal with
it, but I have so many problems all at once." Meanwhile his friend tries
several times to interrupt him, obviously meaning to suggest he
shouldn't drink so much, but gives up. Ad ends in depressed silence.
For some reason your post reminded me of that ad, David. I have no idea
why :-)
--
Mark Hadfield "Ka puwaha te tai nei, Hoea tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)
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| Re: Linux Question [message #42644 is a reply to message #42567] |
Wed, 16 February 2005 16:13 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Paul Van Delst writes:
> Maybe it's because writing code/getting results is *too* easy nowadays? (Thanks, IDL.
> Sheesh. :o) And maybe the ease of writing code that produces copious amounts of data
> contributes to the generation of errors too subtle to stand out?
You may be on to something here. I usually start a
class by asking what people want to learn to do,
and why they've chosen IDL to do it. Inevitably,
they want to do the most god-awful complicated
things. I always start to sweat because I know how
(some of the time) to do about half of it.
Then we get started, and three hours later when
I find myself saying, "No, *DEVICE* decomposed.
D-E-V-I-C-E. You are typing DEVIOUS," that I
realize I'll be fine, that we aren't going very
far that day or any other. It's only later that
night, after the third or forth margarita that
I get very, very depressed.
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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| Re: Linux Question [message #42670 is a reply to message #42567] |
Fri, 18 February 2005 09:54 |
Rick Towler
Messages: 821
Registered: August 1998
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Senior Member |
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Wow, this thread has covered a lot of ground....
Paul Van Delst wrote:
> David wrote:
>
>> Jonathan Greenberg writes:
>>
>>
>>> David: you are the expert on IDL, one thing I haven't figured out is
>>> what does IDL have that Matlab/Octave doesn't?
>>
>> In a word, objects. :-)
>
> I disagree mightily with that, but anyway....
>
> Hasn't matlab been object based from the get go?
As of release 7 it has a mature, fully implemented object API. More so
than IDL. Most everything is an object. This probably raises the bar a
bit for entry into the object club though. IDL's object API is really
easy to pick up. I was a master after a few days of David's tutelage. ;)
> For example, the standard out-of-the-box "plot" in matlab
> has the functionality that I lay awake at
> night dreaming about for IDL plots. You can zoom, change the line
> properties, print, etc. You can probably create legends too (but I'm not
> sure). This is how a regular old "plot" should work in IDL. I guess
> iTools are the attempt to do this in IDL.
Exactly! And if you take much of what has been said in this thread
about "kids these days" and how they don't know anything maybe some of
you can see why iTools was born?
The first time I threw up a plot window in MATLAB I was amazed... So is
just about everyone else who has used products like these. Given a
choice between this and IDL's direct graphics it is a no-brainer.
Sure, iTools have many limitations but I suspect they will be addressed
in future releases.
> - Everything in matlab seems to be a string, 4-byte integer, or 8-byte
> real. What's the go with that?
As of Release 7 you have all of your standard types: char, int8-int48,
uint8-uint64, single, double, complex. And like I said, they're all
objects :)
Other high points?
A great GUI builder where all of the GUI code is hidden, you just deal
with a .m file containing the callbacks (Although IDL does have more
widgets I am so sick of coding GUIs by hand.) *TIGHT* Java integration:
import java.util.GregorianCalendar;
import java.util.TimeZone;
startCal = GregorianCalendar(1601, 0, 1);
gmt = TimeZone.getTimeZone('GMT');
startCal.SetTimeZone(gmt)
Holy cow. Is that Java? MATLAB? Who cares, it works? The MATLAB
compiler is pretty cool too. The user community website is far more
friendly than RSI's. It has a built in C compiler to build MATLAB's
version of .dlms!
MATLAB has some major shortcomings for an IDL user: It doesn't pass by
reference (well, not the way you want it too) and it doesn't have
KEYWORDS (well I don't consider result=myFunc(argIn, 'keyword1', data1,
'keyword2, 'data2') keywords.) The licensing is a PITA. MATLAB is just
as quirky as IDL, maybe more so if you are used to IDL's quirks and
consider them "normal". And try posting on comp.soft-sys.matlab...
With hundreds of posts a day it just isn't as friendly as c.l.idl-pvwave
(And there is *no one* posting about their personal adventures or their
tennis game!)
So at the very least RSI has some stiff competition and they will need
to deliver a quality product and nurture their user base. Michael
started an offshoot regarding (more or less) the latter point. As for
feature requests, I have found RSI to be very receptive. There is a lot
more they could do on the nurturing front though (they still owe me some
posters and t-shirts!) The user contrib site is a great idea but the
interface sucks and the "newsgroup" on the RSI website is just a mean
trick. Those poor users who post there...
-Rick
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| Re: Linux Question [message #42671 is a reply to message #42567] |
Fri, 18 February 2005 09:18 |
Michael Wallace
Messages: 409
Registered: December 2003
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Senior Member |
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> I meant in the sense of a programming language construct.
> There is nothing similar in MatLab, to my knowledge.
> And, frankly, I wouldn't even consider a language these
> days that didn't allow me to start my day writing another
> object. They are just that much fun! :-)
Java objects are fun. IDL "Objects" are.... lets not go there. ;-)
>> Hasn't matlab been object based from the get go? For example, the standard out-of-the-box
>> "plot" in matlab (or , at least, the window that the plot is displayed in) has the
>> functionality that I lay awake at night dreaming about for IDL plots. You can zoom, change
>> the line properties, print, etc. You can probably create legends too (but I'm not sure).
>> This is how a regular old "plot" should work in IDL. I guess iTools are the attempt to do
>> this in IDL.
>
>
> I guess you are right, but why aren't people using
> them, then? When I am in the field I hear, "Oh, I tried
> that, but it seemed too complicated.", or "I couldn't
> figure it out." Maybe the tutorials will help (assuming
> we can get the directions to match the save files).
My problem with iTools was that you can't use them pro grammatically.
Say I create an iplot and add a few annotations and get something that I
really like. I'd like the ability to save off the positional and size
information to a template and use that template over and over as I
iterate through my data. Load the template, set the X data vector, set
the Y data vector, set the title strings, and save the view off to a file.
I guess what I'm describing is using the iTool to handle your object
graphics code for you. It's much easier to define the look of plot if
you're able to do it graphically rather than messing with the code for
all the views, models, plots and other objects. It would simplify the
coding greatly and as such would be less error prone.
Back when iTools were introduced I was told from someone at RSI that you
couldn't do stuff like this. Everything was designed to be used in an
ad hoc way. Even something as simple as pro grammatically switching out
your data vectors only wasn't possible. What's the point of using the
iTool if you can't reuse it?
-Mike
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| Re: Linux Question [message #42673 is a reply to message #42567] |
Fri, 18 February 2005 08:01 |
btt
Messages: 345
Registered: December 2000
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Senior Member |
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Paul Van Delst wrote:
> David wrote:
>
>> Jonathan Greenberg writes:
>>
>>
>>> David: you are the expert on IDL, one thing I haven't figured out is
>>> what
>>> does IDL have that Matlab/Octave doesn't? As a remote sensor, I use IDL
>>> because of this interface with ENVI. However, why do non-envi users
>>> use IDL
>>> (except for sheer inertia of not wanting to learn a new program)?
>>
>>
>>
>> In a word, objects. :-)
>
>
>
> As to the OP question of "why do non-envi users use IDL" ? Well, in my
> case, it's because the matlab licensing procedure appears (horror of
> horrors) to be even more labyrinthine than that for IDL (how can that
> be!?!). Oh, and:
> - I have a crapload of IDL code
> - Everything in matlab seems to be a string, 4-byte integer, or 8-byte
> real. What's
> the go with that?
Well, I dunno. Your info might be a bit dated. The link below points to the
*very nice* online MatLab help system - in particular look at the 'Data Types'
link on the page. This shows that MatLab seems to comparable data types (except
complex, I think) and that there exists such a thing as 'User Class'. I
couldn't begin to tell you if they are comparable to IDL objects.
http://tinyurl.com/3gpdo
Tears,
Ben
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| Re: Linux Question [message #42674 is a reply to message #42567] |
Fri, 18 February 2005 07:43 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Paul Van Delst writes:
>> In a word, objects. :-)
>
> I disagree mightily with that, but anyway....
I meant in the sense of a programming language construct.
There is nothing similar in MatLab, to my knowledge.
And, frankly, I wouldn't even consider a language these
days that didn't allow me to start my day writing another
object. They are just that much fun! :-)
> Hasn't matlab been object based from the get go? For example, the standard out-of-the-box
> "plot" in matlab (or , at least, the window that the plot is displayed in) has the
> functionality that I lay awake at night dreaming about for IDL plots. You can zoom, change
> the line properties, print, etc. You can probably create legends too (but I'm not sure).
> This is how a regular old "plot" should work in IDL. I guess iTools are the attempt to do
> this in IDL.
I guess you are right, but why aren't people using
them, then? When I am in the field I hear, "Oh, I tried
that, but it seemed too complicated.", or "I couldn't
figure it out." Maybe the tutorials will help (assuming
we can get the directions to match the save files).
> As to the OP question of "why do non-envi users use IDL" ? Well, in my case, it's because
> the matlab licensing procedure appears (horror of horrors) to be even more labyrinthine
> than that for IDL (how can that be!?!). Oh, and:
> - I have a crapload of IDL code
> - Everything in matlab seems to be a string, 4-byte integer, or 8-byte real. What's
> the go with that?
I was just thinking in the shower that one of the reasons MatLab
can get retaining of windows right from the start is that it
probably *always* does the equivalent of RETAIN=2. IDL is
probably more flexible than MatLab in any number of ways, which
is it's power and curse. What IDL does wrong, I think, is
assume the user is going to read the documentation. It needs
better default cases, and the documentation needs to be written
from the point of view of a user and not a developer, especially
with regard to how to get your computer set up to work with
IDL. (Oh, and then they could fix the TV command so that it
works like IMGDISP or TVIMAGE, but I guess that's another story.)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
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| Re: Linux Question [message #42676 is a reply to message #42567] |
Fri, 18 February 2005 07:25 |
Paul Van Delst[1]
Messages: 1157
Registered: April 2002
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Senior Member |
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David wrote:
> Jonathan Greenberg writes:
>
>
>> David: you are the expert on IDL, one thing I haven't figured out is what
>> does IDL have that Matlab/Octave doesn't? As a remote sensor, I use IDL
>> because of this interface with ENVI. However, why do non-envi users use IDL
>> (except for sheer inertia of not wanting to learn a new program)?
>
>
> In a word, objects. :-)
I disagree mightily with that, but anyway....
Hasn't matlab been object based from the get go? For example, the standard out-of-the-box
"plot" in matlab (or , at least, the window that the plot is displayed in) has the
functionality that I lay awake at night dreaming about for IDL plots. You can zoom, change
the line properties, print, etc. You can probably create legends too (but I'm not sure).
This is how a regular old "plot" should work in IDL. I guess iTools are the attempt to do
this in IDL.
As to the OP question of "why do non-envi users use IDL" ? Well, in my case, it's because
the matlab licensing procedure appears (horror of horrors) to be even more labyrinthine
than that for IDL (how can that be!?!). Oh, and:
- I have a crapload of IDL code
- Everything in matlab seems to be a string, 4-byte integer, or 8-byte real. What's
the go with that?
> P.S. I'm not sure there is much difference between Matlab and
> IDL users. You would be better off asking why some people are
> Methodist and some people are Baptist. It's just a matter of
> preference, I guess. :-)
It's not intrinsic though - a learned response *can* be unlearned (be it computer
languages or religions). Once the aforementioned inertia is overcome, of course. (For
some reason the the song "We shall not be moved" just popped into my head.... :o)
paulv
--
Paul van Delst
CIMSS @ NOAA/NCEP/EMC
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| Re: Linux Question [message #42691 is a reply to message #42567] |
Thu, 17 February 2005 21:24 |
mperrin+news
Messages: 81
Registered: May 2001
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Member |
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David Fanning, Ph.D. <david@dfanning.com> wrote:
> Jonathan Greenberg writes:
>
>> David: you are the expert on IDL, one thing I haven't figured out is what
>> does IDL have that Matlab/Octave doesn't? As a remote sensor, I use IDL
>> because of this interface with ENVI. However, why do non-envi users use IDL
>> (except for sheer inertia of not wanting to learn a new program)?
>
> In a word, objects. :-)
Another answer, also related to intertia, is the sheer mass of already
existant code. Speaking again from the parochial perspective of us
star-gazers, I can't imagine any mass migration until Matlab or Octave
have something comparable to the Goddard idlastro library.
Notably, the Python guys are actually working on creating just such a thing;
I'll be very interested to see how that progresses in coming years.
- Marshall
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| Re: Linux Question [message #42693 is a reply to message #42567] |
Thu, 17 February 2005 17:41 |
Jonathan Greenberg
Messages: 91
Registered: November 2002
|
Member |
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So I have to say I've actually been VERY surprised with how quick RSI is to
respond -- I've seen bug reports I've submitted get seriously considered and
folded into future releases. I should point out I work mostly with ENVI,
using IDL to support remote sensing work. Most of the features have been
remote sensing related, which begs the question of whether RSI has a big
difference in their IDL techs and their ENVI techs.
David: you are the expert on IDL, one thing I haven't figured out is what
does IDL have that Matlab/Octave doesn't? As a remote sensor, I use IDL
because of this interface with ENVI. However, why do non-envi users use IDL
(except for sheer inertia of not wanting to learn a new program)?
--j
On 2/17/05 12:23 PM, in article 1119vbenc668267@corp.supernews.com, "Michael
Wallace" <mwallace.no.spam@no.spam.swri.edu.invalid> wrote:
>>> Please don't spoil my phantasy! I hope really to overcome this
>>> unbelievable corruption of thinking caused by the usage of MS software!
>>
>>
>> Well, I was going to respond, but apparently my thinking has been
>> corrupted, unbelievably.
>
> Quoth the Borg (underwritten by M$), "You have been assimilated.
> Resistance is futile."
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| Re: Linux Question [message #42736 is a reply to message #42693] |
Mon, 21 February 2005 01:40 |
Nigel Wade
Messages: 286
Registered: March 1998
|
Senior Member |
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|
Jonathan Greenberg wrote:
> So I have to say I've actually been VERY surprised with how quick RSI is
to
> respond -- I've seen bug reports I've submitted get seriously considered
and
> folded into future releases. I should point out I work mostly with ENVI,
> using IDL to support remote sensing work. Most of the features have been
> remote sensing related, which begs the question of whether RSI has a big
> difference in their IDL techs and their ENVI techs.
>
> David: you are the expert on IDL, one thing I haven't figured out is what
> does IDL have that Matlab/Octave doesn't?
Direct graphics. Everything in MATLAB is an "object". When you plot millions
of little blocks, every block is an "object" containing its coordinates,
the fill colour, the fill style, the outline colour, the outline style etc.
The overhead is enormous.
The ability to work with non-double-precision numbers. Whilst MATLAB allows
you to create matrices containing non-DP numbers, you can't actually do
anything with them. Try adding 1 to one for example - result "that
operation is not supported".
A draconian licensing model. IDL requires 1 license per user per host. That
user can run any number of IDL sessions on the same host and requires only
1 license. MATLAB requires 1 license per invocation.
MATLAB comes as a pretty bare installation. If you want any functionality to
get some real work done you are going to have to cough up additional money
for some toolboxes.
--
Nigel Wade, System Administrator, Space Plasma Physics Group,
University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@ion.le.ac.uk
Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555
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