| Object Programming in IDL [message #30832] |
Tue, 21 May 2002 05:26  |
graham_wilson_1234
Messages: 1
Registered: May 2002
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Junior Member |
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Just to appease Craig, I have started a new thread so I can avoid putting my
comments after David's 'gosh golly' post ;) I am interested in hearing
others comments...
The first point that we should all be very clear on is that IDL is _NOT_
a particularly good example of an object oriented language. You can
certainly emulate OOP concepts using IDL's objects and a select few
functions/proceedures but if often defeats the purpose of the OOP style.
When someone mentions IDL objects, it is universally assumed that they
really mean 'object graphics' which leads directly to point number 2;
Object oriented programming != object graphics. Unfortunately, it
is very difficult to dispel this myth using IDL because of point number 1.
With regard to writing object oriented code in IDL we are all rather stuck
until RSI implements a more complete feature set. I generally define
polymorphism it as the ability to process objects differently depending on
their data type or class. In this respect, the lack of operator overloading
is an example where IDL fails to offer the full OOP tool set. Yes, you can
overload methods, but operators should be no different. To compensate for
this missing functionality one can write functions and/or procedures but
this better described as an overlay and you must rely on a naming
convention or a path precidence to avoid conflicts. Personally, I'd like
to see true polymorphism (with overloading) and public/private methods
sooner rather than later (is anyone at RSI listening?).
A good technical book describing the merits of using objects in data
analysis is "Programming with Data: A Guide to the S Language"
(ISBN: 0-387-98503-4). The concepts described are specific to S-Plus but
can be adapted to any OOP language. While they may seem abstract at first,
they are very powerful way of manipulating and modelling data. A free
alternative to S-Plus is R (www.r-project.com).
For what it is worth, Matlab has a slightly more complete implementation of
OOP. The one glaring (and annoying) feature missing from Matlab, however,
is the absence of pointers and therefore dynamic structures/sizing. This,
of course, is a grip for a different newsgroup...
I lurk therefore I am.
Graham
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| Re: Object Programming in IDL [message #30873 is a reply to message #30832] |
Fri, 24 May 2002 01:53  |
R.Bauer
Messages: 1424
Registered: November 1998
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Senior Member |
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Dear Graham,
I hope you already have done a feature request to RSI directly.
At the moment it's not clear to me why you believe this feature
is so important for the IDL language.
The parts of Object Language already in IDL implemented
are full working or not ?
regards
Reimar
Graham Wilson wrote:
>
> Just to appease Craig, I have started a new thread so I can avoid putting my
> comments after David's 'gosh golly' post ;) I am interested in hearing
> others comments...
>
> The first point that we should all be very clear on is that IDL is _NOT_
> a particularly good example of an object oriented language. You can
> certainly emulate OOP concepts using IDL's objects and a select few
> functions/proceedures but if often defeats the purpose of the OOP style.
> When someone mentions IDL objects, it is universally assumed that they
> really mean 'object graphics' which leads directly to point number 2;
> Object oriented programming != object graphics. Unfortunately, it
> is very difficult to dispel this myth using IDL because of point number 1.
>
> With regard to writing object oriented code in IDL we are all rather stuck
> until RSI implements a more complete feature set. I generally define
> polymorphism it as the ability to process objects differently depending on
> their data type or class. In this respect, the lack of operator overloading
> is an example where IDL fails to offer the full OOP tool set. Yes, you can
> overload methods, but operators should be no different. To compensate for
> this missing functionality one can write functions and/or procedures but
> this better described as an overlay and you must rely on a naming
> convention or a path precidence to avoid conflicts. Personally, I'd like
> to see true polymorphism (with overloading) and public/private methods
> sooner rather than later (is anyone at RSI listening?).
>
> A good technical book describing the merits of using objects in data
> analysis is "Programming with Data: A Guide to the S Language"
> (ISBN: 0-387-98503-4). The concepts described are specific to S-Plus but
> can be adapted to any OOP language. While they may seem abstract at first,
> they are very powerful way of manipulating and modelling data. A free
> alternative to S-Plus is R (www.r-project.com).
>
> For what it is worth, Matlab has a slightly more complete implementation of
> OOP. The one glaring (and annoying) feature missing from Matlab, however,
> is the absence of pointers and therefore dynamic structures/sizing. This,
> of course, is a grip for a different newsgroup...
>
> I lurk therefore I am.
> Graham
--
Reimar Bauer
Institut fuer Stratosphaerische Chemie (ICG-I)
Forschungszentrum Juelich
email: R.Bauer@fz-juelich.de
------------------------------------------------------------ -------
a IDL library at ForschungsZentrum Juelich
http://www.fz-juelich.de/icg/icg1/idl_icglib/idl_lib_intro.h tml
============================================================ =======
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| Re: Object Programming in IDL [message #30885 is a reply to message #30832] |
Thu, 23 May 2002 08:47 |
Pavel A. Romashkin
Messages: 531
Registered: November 2000
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Senior Member |
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I think by now only a few people equate objects with object graphics.
This topic was brought up way too many times for that.
I think objects in IDL are very useful. They speed up development, help
write reuseable code and make it easy to maintain. They may not be
perfect but again - if anyone knows of any tool, be it programming
language, a car or anything else - let us all know so we can all switch.
I think I will stay with IDL over C++ for data processing applications,
despite the lack of operator overloading in IDL.
Cheers,
Pavel
Graham Wilson wrote:
>
> Just to appease Craig, I have started a new thread so I can avoid putting my
> comments after David's 'gosh golly' post ;) I am interested in hearing
> others comments...
>
> The first point that we should all be very clear on is that IDL is _NOT_
> a particularly good example of an object oriented language. You can
> certainly emulate OOP concepts using IDL's objects and a select few
> functions/proceedures but if often defeats the purpose of the OOP style.
> When someone mentions IDL objects, it is universally assumed that they
> really mean 'object graphics' which leads directly to point number 2;
> Object oriented programming != object graphics. Unfortunately, it
> is very difficult to dispel this myth using IDL because of point number 1.
>
> With regard to writing object oriented code in IDL we are all rather stuck
> until RSI implements a more complete feature set. I generally define
> polymorphism it as the ability to process objects differently depending on
> their data type or class. In this respect, the lack of operator overloading
> is an example where IDL fails to offer the full OOP tool set. Yes, you can
> overload methods, but operators should be no different. To compensate for
> this missing functionality one can write functions and/or procedures but
> this better described as an overlay and you must rely on a naming
> convention or a path precidence to avoid conflicts. Personally, I'd like
> to see true polymorphism (with overloading) and public/private methods
> sooner rather than later (is anyone at RSI listening?).
>
> A good technical book describing the merits of using objects in data
> analysis is "Programming with Data: A Guide to the S Language"
> (ISBN: 0-387-98503-4). The concepts described are specific to S-Plus but
> can be adapted to any OOP language. While they may seem abstract at first,
> they are very powerful way of manipulating and modelling data. A free
> alternative to S-Plus is R (www.r-project.com).
>
> For what it is worth, Matlab has a slightly more complete implementation of
> OOP. The one glaring (and annoying) feature missing from Matlab, however,
> is the absence of pointers and therefore dynamic structures/sizing. This,
> of course, is a grip for a different newsgroup...
>
> I lurk therefore I am.
> Graham
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| Re: Object Programming in IDL [message #30946 is a reply to message #30832] |
Fri, 24 May 2002 11:14 |
Craig Markwardt
Messages: 1869
Registered: November 1996
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Senior Member |
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"Dick Jackson" <dick@d-jackson.com> writes:
>>
>> Ahh, don't worry Graham, I don't normally read object postings :-)
>
> This reminds me of one posting I read in comp.object, a group for
> discussions of O-O issues in any language. During a rather intense argument
> among people with very strong opinions, someone pointed out that in the name
> of the newsgroup, "object" was the noun, not the verb.
>
> Which did you mean, Craig? :-)
Heh, I like the ambiguity. :-)
Craig
--
------------------------------------------------------------ --------------
Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
------------------------------------------------------------ --------------
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| Re: Object Programming in IDL [message #30965 is a reply to message #30876] |
Fri, 24 May 2002 07:51 |
Dick Jackson
Messages: 347
Registered: August 1998
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Senior Member |
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"Craig Markwardt" <craigmnet@cow.physics.wisc.edu> wrote in message
news:on7klui7fu.fsf@cow.physics.wisc.edu...
>
> graham_wilson_1234@yahoo.ca (Graham Wilson) writes:
>
>> Just to appease Craig, I have started a new thread so I can avoid
putting my
>> comments after David's 'gosh golly' post ;) I am interested in hearing
>> others comments...
>
> Ahh, don't worry Graham, I don't normally read object postings :-)
This reminds me of one posting I read in comp.object, a group for
discussions of O-O issues in any language. During a rather intense argument
among people with very strong opinions, someone pointed out that in the name
of the newsgroup, "object" was the noun, not the verb.
Which did you mean, Craig? :-)
Cheers,
--
-Dick
Dick Jackson / dick@d-jackson.com
D-Jackson Software Consulting / http://www.d-jackson.com
Calgary, Alberta, Canada / +1-403-242-7398 / Fax: 241-7392
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| Re: Object Programming in IDL [message #30969 is a reply to message #30873] |
Fri, 24 May 2002 04:59 |
Paul Van Delst[1]
Messages: 1157
Registered: April 2002
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Senior Member |
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Reimar Bauer wrote:
>
> Dear Graham,
>
> I hope you already have done a feature request to RSI directly.
>
> At the moment it's not clear to me why you believe this feature
> is so important for the IDL language.
I use operator overloading in Fortran 90/95 all the time for derived type (structure)
arithmetic. Not just overloading existing operators either - you can define new ones too.
Very handy. If it's useful in Fortran, well then....
> The parts of Object Language already in IDL implemented
> are full working or not ?
I think that (and here I'm wildly speculating on Grahams POV) is that the emphasis is on
the word "parts" in the above sentence.
paulv
--
Paul van Delst Religious and cultural
CIMSS @ NOAA/NCEP/EMC purity is a fundamentalist
Ph: (301)763-8000 x7274 fantasy
Fax:(301)763-8545 V.S.Naipaul
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